19 Nov 17:38
by Piyush Singh,
Pradip Pattanayak,
Pradipta Purkayastha,
Sujit Kumar Ghosh
The graphical abstract depicts two reverse intersystem crossing (rISC) pathways through the Jablonski diagram: the traditional thermally activated delayed fluorescence (TADF) channel on the left with yellow sunny background and a new, cold rISC pathway on the right in blue.
Abstract
In recent years, understanding the mechanism of thermally activated delayed fluorescence (TADF) has become the primary choice for designing high-efficiency, low-cost, metal-free organic light emitting diodes (OLEDs). Herein, we propose a strategically designed chalcone based donor-acceptor system, where intensification of delayed fluorescence with decrease in temperature (300 K to 100 K) is observed; the theoretical investigations of electronic states and orbital characters uncovered a new cold rISC pathway in donor-acceptor system, where rISC occurs through the down-conversation of higher triplet exciton (from T3) to lowest singlet state (S1), having negative energy splitting, thus no thermal energy is required. The comprehensive research described herein might open-up new avenues in donor-acceptor system over the conventional up-convention of triplet exciton and demonstrates that not necessarily all delayed fluorescence are thermally activated (TADF).
24 Oct 05:40
by Shanyue Hou,
Zhu Ma,
Yanlin Li,
Zhuowei Du,
Yi Chen,
Junbo Yang,
Wei You,
Qiang Yang,
Tangjie Yu,
Zhangfeng Huang,
Guomin Li,
Haoyu Wang,
Qianyu Liu,
Guangyuan Yan,
Haimin Li,
Yuelong Huang,
Wenhua Zhang,
Mojtaba Abdi‐Jalebi,
Zeping Ou,
Kuan Sun,
Rong Su,
Wei Long
While heterojunctions with intermixed or gradient perovskites can reduce surface recombination, the aggregation and phase distribution of 2D perovskite induce transport losses, thereby limiting device fill factors. Accordingly, bulk in situ reconstruction (BISR) strategy is proposed to induce the reconstruction of 3D perovskites on a minim self-assembled 2D crystal seed, forming heterojunction perovskite that runs through the entire active layer.
Abstract
Heterojunction perovskite solar cells combine the stability of 2D perovskites and the high efficiency of 3D perovskites, making them an excellent photovoltaic candidate. While heterojunctions with intermixed or gradient perovskites can reduce surface recombination, the aggregation and phase distribution of 2D perovskite induce transport losses, thereby limiting device fill factors. Accordingly, a bulk in situ reconstruction (BISR) strategy is proposed to induce the reconstruction of 3D perovskites on a minim self-assembled 2D crystal seed, forming heterojunction perovskite that runs through the entire active layer. This facilitates charge extraction, relieves tensile stress, and avoids the decomposition of perovskite on grain boundaries. As a result, the best-performing heterojunction perovskite solar cells show a high-power conversion efficiency (PCE) of 24.06% with 82.9% FF for the small-area device (0.105 cm2) and a superior PCE of 19.2% for the large-area module (5 × 5 cm2). Importantly, the unencapsulated device shows dramatically improved operational stability, maintaining 87% of its initial efficiency after 8000 h of storage under ambient atmosphere at room temperature. This work provides an effective and simple approach to establish heterojunction perovskite to simultaneously boost the efficiency and stability of PSCs.
24 Oct 05:39
by Huanxin Yang,
Xiangxiang Chen,
Haolin Lu,
Yue Li,
Wenda Sun,
Yuhai Zhang,
Xiaowang Liu,
Guankui Long,
Libing Zhang,
Xiyan Li
Ultrabroad warm-white afterglow are first realized based on self-trapped excitons (STEs) of lead-free perovskites Cs2NaInCl6:Ag,Bi by room-temperature engineering. Ag and Bi guests enhance the quantum yield and afterglow performance, simultaneously, contributing to a remarkable afterglow persistence of over 20,000 s. The dynamic afterglow model for STEs is concluded and multi-channel information system are designed for prospectively intelligent applications.
Abstract
In the era of intelligence, the output colors of foundational phosphors are expected to be controlled by programs, while current activators-determined afterglow candidates with fixed spectral channel have limitations in creating customized colors. Here, a long-lived warm-white emission is successfully demonstrated originating from self-trapped excitons (STEs) in non-toxic Cs2NaInCl6:Ag,Bi, ranging from 400 to 850 nm, of which the afterglow color can be easily customized using filters. This investigation indicates that 3% of Ag alloying breaks the dark STEs and introduces traps for efficient afterglow, while 3% Bi doping further improves the quantum yield to ≈100% and greatly enhances afterglow by ≈100-fold compared with the initial intensity, allowing for an impressive afterglow persistence of over 20,000 s. Intriguingly, the self-trapped defect bands from Jahn-Teller distortions are prolonged from hundreds of femtoseconds to several hours, and they are first detected in the steady-state absorption spectra after the cessation of excitation sources, contributing to the concluded dynamic afterglow model for STEs. And its intelligent application is corroborated by designed multi-channel information system. These findings offer a novel scheme for understanding dynamic luminescence of STEs and supply an exemplification of designing white afterglow phosphors.
17 Oct 16:40
by Guanming Liao,
Jinyu Lei,
Shuxin Li,
Meiyan Liu,
Yali Qiao,
Kanglei Liu,
Nan Wang,
Quan Niu,
Xiaodong Yin
Spiro boron-nitrogen compounds with highly efficient photoluminescent properties are synthesized and exhibit typical thermally activated delayed fluorescence character both in solution and solid states. TPA-s-FMesBF exhibit excellent photo luminescent stability with almost identical photoluminescence properties in doped film and neat films, leading to an excellent EQE of 22.1% for the TPA-s-FMesBF based solution-processed organic light-emitting diode.
Abstract
Spiro compounds with unique structural and electronic properties are beneficial for thermally activated delayed fluorescence (TADF) emitters. Herein, a series of spiro boron-nitrogen (B-N) compounds are reported with donor–acceptor (D-A) interaction through homoconjugation. Three phenyl acridine-containing spiro B-N compounds exhibit highly efficient photoluminescence (PL) in degassed toluene and solid-state with obvious TADF character. The separation of HOMO and LUMO for these compounds is confirmed by theoretical calculations, as is the small ΔE
ST of phenyl acridine-containing compounds. These three compounds are used as emitting layers in solution-processed organic light-emitting diodes (OLEDs), resulting in deep-blue to green emission colors with different acceptor moieties. Impressively, an excellent external quantum efficiency (EQE) of 22.1% is recorded for the TPA-s-FMesBF-based OLED device, which is comparable with the highest value from solution-processed OLEDs based on spiro D-A emitting materials. This work presents a facile synthetic route to novel B, N-substituted spiro compounds, as well as the structure-property relationship of spiro D-A compounds for highly efficient TADF emitters.
17 Oct 16:39
by Hui‐Ying Luo,
Yan Guan,
Jiang Huang,
Zhi‐Wang Luo,
Ao Huang,
Ping Wang,
He‐Lou Xie
Circularly polarized delayed fluorescence (CP-DF) with a glum of −0.042 is successfully realized based on carbonized polymer dot liquid crystal (CPDs-Chol) through regulating the energy splitting (ΔEST) between the lowest singlet (S1) and triplet (T1) excited states, which shows an attractive photonic technology with advanced applications in anti-counterfeiting and information encryption.
Abstract
Circularly polarized luminescence (CPL) as modern photonic technology is essential for optical apparatuses, anti-counterfeiting, and information encryption. However, it still faces the formidable challenge of integrating delayed fluorescence into CPL through harvesting the triplet excitons. Herein, a carbonized polymer dot liquid crystal (CPDs-Chol) is reported that shows both circularly polarized fluorescence (CPF) and circularly polarized delayed fluorescence (CP-DF). In order to realize the CP-DF, a kind of CPDs-Chol is successfully designed and synthesized through grafting cholesterol molecules on the surface of novel carbonized polymer dots (CPDs) possessing long afterglow of 13 s. Then, the resultant CPDs-Chol is doped with 4-cyano-4-pentylbiphenyl (5CB) in different ratios to fabricate CPL material, which shows the highest glum of −0.5 and −0.042 for CPF and CP-DF, respectively. The combination of the CPL feature and the long afterglow of CPDs-Chol@5CB and CPDs offer an attractive photonic technology with advanced applications in anti-counterfeiting and information encryption.
17 Oct 16:38
by Jinho Park,
Seung Chan Kim,
Unhyeok Jo,
Dong Ryun Lee,
Han Jin Ahn,
Jun Yun Kim,
Ji‐Ho Baek,
Jun Yeob Lee
Highly efficient, narrow-emitting violet materials based on boron and oxygen polycyclic aromatic hydrocarbon multiple resonance structure achieve a high external quantum efficiency of over 15%, violet emission with a peak wavelength of 423 nm, and CIE chromaticity coordinates of (0.156, 0.037).
Abstract
This study proposes a novel approach to develop highly efficient, narrow-emitting violet materials based on boron and oxygen polycyclic aromatic hydrocarbon multiple resonance structure. Herein, B-2OCz is developed by fusing indole with a 5,9-dioxa-13bboranaphtho[3,2,1-de]anthracene (DOBNA) core to enhance its thermally activated delayed fluorescence (TADF) properties and molecular rigidity. On the other hand, the B-2OCz-Si is decorated with a bulky tetraphenylsilyl substituent. B-2OCz-Si exhibits exceptional features such as violet emission at 397 nm, a very small full width at half maximum of 16 nm, and 82% of photoluminescence quantum yield. The B-2OCz-Si devices achieve a high external quantum efficiency of over 15%, violet emission with a peak wavelength of 423 nm, and color coordinates of (0.156, 0.037). Furthermore, the B-2OCz-Si is used as an electron transport type host material for phosphorescent organic light-emitting diodes (PhOLEDs), based on its high triplet energy and TADF properties. As compared to the conventional triazine based host materials, these newly developed DOBNA-based materials display superior device lifetime performance. All these potential aspects corroborate that this new class of DOBNA-based materials can work as a promising host material for PhOLEDs and violet-emitting fluorescent devices.
17 Oct 16:38
by Yaxiong Wei,
Kebin An,
Xinsheng Xu,
Zeyuan Ye,
Xiaojun Yin,
Xiaosong Cao,
Chuluo Yang
The high efficiency example of pure-organic near-infrared to blue triplet–triplet annihilation upconversion is presented by employing a π-radical photosensitizer. This heavy-atom-free approach achieves notable upconversion efficiency, large anti-Stokes shift, and exceptional photostability, offering the potential for applications in photovoltaics, photocatalysis, bioimaging, and additional fields.
Abstract
Near-infrared (NIR)-to-blue triplet–triplet annihilation upconversion (TTA-UC) exhibits substantial potential for diverse applications, encompassing photovoltaics, photocatalysis, bioimaging, and photodynamic therapy. A major challenge in this field, however, is attaining high upconversion quantum yields (Φ
UC) without using transition metals as NIR photosensitizers. This research presents an innovative organic π-radical photosensitizer (TTM-TPA) featuring extended absorption in the NIR region (≈760 nm) that is capable of generating pronounced anti-Stokes emissions when coupled with suitable triplet acceptors. By eliminating energy loss associated with intersystem crossing and promoting rapid doublet–triplet energy transfer processes, the binary TTM-TPA/perylene system achieves Φ
UC values of up to 6.8% and an anti-Stokes shift of 0.93 eV. Notably, the TTA-UC system demonstrates exceptional stability when subjected to intense 733 nm laser irradiation (4 W cm−2), maintaining nearly constant upconversion intensity after 4 h. These findings underscore the considerable potential of doublet-sensitized TTA-UC for a broad array of practical applications.
17 Oct 16:37
by Nagaraju Peethani,
Na Yeon Kwon,
Chang Woo Koh,
Su Hong Park,
Jung Min Ha,
Min Ju Cho,
Han Young Woo,
Sungnam Park,
Dong Hoon Choi
A simple molecular design strategy is proposed to suppress both aggregation-related issues and efficiency roll-off in the planar multi-resonance (MR) framework by strategically encapsulating the structure with bulkier phenyl-fluorene units. This design approach effectively mitigates efficiency roll-off and achieves excellent external quantum efficiency (EQE) in the corresponding OLED.
Abstract
Multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters exhibit enormous potential for use in organic light-emitting diodes (OLEDs), owing to their exceptional external quantum efficiencies (EQEs) and narrowband emission spectra. However, planar MR-TADF emitters often suffer from aggregation-caused quenching (ACQ) and spectral broadening at high doping concentrations because of strong interchromophore π–π interactions. A method of sterically encapsulating the planar MR skeleton with four bulky 9-phenyl-fluorene (Fl) units is devised, resulting in the development of a bright bluish-green emitter (4FlCzBN). This steric shielding effectively reduces intermolecular interactions, suppresses ACQ, and improves solubility. Consequently, by utilizing 4FlCzBN as a doping-insensitive MR emitter, solution-processed OLEDs are fabricated with doping concentrations of 2–16 wt.%, and they show EQEs of 10.1–10.9% with a bandwidth of 28–30 nm. Furthermore, a TADF-sensitizer-based device using 4FlCzBN demonstrates a significantly reduced efficiency roll-off while achieving an EQE of 12.2%. This is a remarkable improvement that overcomes the disadvantages that are difficult to achieve in previously reported MR-TADF OLEDs. The current work provides valuable insights into the design of efficient MR-TADF emitters with minimized aggregation and reduced efficiency roll-off for solution processing.
17 Oct 16:37
by Yijie Wang,
Shengju Zhou,
Shengmei Pan,
Xiaofeng Sun,
Jin Zhou,
Hongguang Li
Color-tunable carbon dots (CDs) with aggregation-induced emission (AIE) are prepared by simply changing the filling ratio of the autoclave in this work. These CDs all exhibit blue fluorescence in dilute solution, and aggregation-induced redshift behaviors are observed when the CDs form aggregates. Multicolor fluorescence is caused by increased fluorescence resonance energy transfer (FRET) efficiency among the dual emission (green/red) peaks.
Abstract
As a class of new fluorescent materials, carbon dots (CDs) have drawn widespread attention by virtue of their tunable photoluminescence (PL), excellent biocompatibility, and novel physicochemical properties. Unfortunately, in solid state, most CDs experience serious aggregation-caused quenching (ACQ). In this work, color-tunable CDs with aggregation-induced emission (AIE) are prepared by simply changing the filling ratio of the autoclave. The obtained CDs show dual emission (green/red) in solid state, and the fluorescent color can be tuned from green to red. These CDs all exhibit blue fluorescence in dilute solution, and aggregation-induced redshift behaviors are observed when the CDs form aggregates. Structural and optical characterizations prove that blue fluorescence is contributed by the carbon cores, whereas the green/red emission is attributed to the surface groups. Multicolor fluorescence is caused by increased fluorescence resonance energy transfer (FRET) efficiency among the dual emission (green/red) peaks from g-CDs to r-CDs. Surprisingly, delayed fluorescence (DF) of CDs are brightened by inserting the CDs into poly(vinyl alcohol) (PVA) films, which can be easily recognized by the naked eyes with a lifetime up to ms. Finally, owing to the unique AIE and DF properties, the four CDs can be applied to multimodal advanced anti-counterfeiting and information encryption.
17 Oct 16:36
by Xinrui Chen,
Sergey Bagnich,
Robert Pollice,
Bing Li,
Yuanyuan Zhu,
Rishabh Saxena,
Yixiao Yin,
Weiguo Zhu,
Alan Aspuru‐Guzik,
Eli Zysman‐Colman,
Anna Köhler,
Yafei Wang
Three structurally related charge transfer-based compounds DPS-m-bAc, DPS-p-bAc, and DPS-OAc are prepared. Notably, compound DPS-m-bAc shows the fastest reverse intersystem crossing rate constant of the three of over 107 s−1 in a doped PMMA film as a result of the very small singlet-triplet gap. A maximum external quantum efficiency of 21.7% is achieved for the DPS-m-bAc-based solution-processed device.
Abstract
Intramolecular through-space charge transfer thermally activated delayed fluorescence (TSCT-TADF) has attracted much attention recently as it can achieve both small energy splitting and high emission efficiency. However, the relationship of excited states between TSCT and through-bond charge transfer (TBCT) remains a challenge in the TSCT-TADF molecules. Herein, three compounds DPS-m-bAc, DPS-p-bAc, and DPS-OAc that possess emissive TSCT and/or TBCT states are prepared. Interestingly, a so-called inverted energy gap is found for both DPS-m-bAc and DPS-p-bAc in toluene solution, which results from the different charge transfer states of ICThigh and ICTlow, as proved by the detailed transient photoluminescence and calculated results. Intense emission from blue to yellow associated with high photoluminescence quantum yields of 70–100% are measured in doped polymethyl(methacrylate) (PMMA) films. Notably, compound DPS-m-bAc achieves the highest reverse intersystem crossing rate constant (k
RISC) of over 107 s−1 in a PMMA film, benefiting from close-lying TSCT and TBCT states. The solution-processed device with DPS-m-bAc displays a maximum external quantum efficiency of 21.7% and a relatively small efficiency roll-off (EQE of 20.2% @ 100 cd m−2). Overall, this work demonstrates how with judicious emitter engineering, a synergy between different charge transfer excited states, can be achieved, providing an avenue to achieve highly efficient solution-processed OLEDs.
17 Oct 16:18
by Yuchao Liu,
Yanchao Xie,
Lei Hua,
Shengyu Li,
Xingwen Tong,
Shian Ying,
Shouke Yan,
Zhongjie Ren
A feasible molecular design strategy for thermally activated delayed fluorescence (TADF) polymers is proposed by combining a spatially confined conjugated backbone and the saturated spiro junction to achieve blue emission. The resulted solution-processed blue TADF polymer light-emitting diodes exhibit record-high performance with an external quantum efficiency of 20.5%.
Abstract
The concept of thermally activated delayed fluorescence (TADF) conjugated polymers has the advantage of enabling solution-processable devices and harnessing singlet and triplet excitons simultaneously, whereas the resultant redshift of emission spectra and inevitable drop-off of triplet excited states are detrimental to exploring high-efficiency blue conjugated polymeric emitters. Herein, a feasible molecular design strategy is proposed by combining a spatially confined conjugated backbone and a TADF moiety isolated by a saturated spiro spacer to enable blue emission in newly designed partly conjugated TADF polymers, simultaneously achieving an excellent photoluminescence quantum yield of over 80% and a relatively high reverse intersystem crossing rate of 4.2 × 105 s−1. Endowed by superior photophysical properties and balanced carrier mobility, a maximum external quantum efficiency of 20.5% is achieved with emission at 486 nm and Commission Internationalede l'Eclairage coordinates of (0.18, 0.31), which is so far the highest efficiency for solution-processed blue TADF polymer light-emitting diodes.
17 Oct 16:18
by Jie Yan,
Min Song,
Dong‐Ying Zhou,
Guowei Ni,
Muhua Gu,
Shek‐Man Yiu,
Xiuwen Zhou,
Liang‐Sheng Liao,
Yun Chi
Saturated-red and near-infrared emissive bis-tridentate Ir(III) complexes are synthesized. The representative organic light-emitting diode (OLED) devices exhibit maximum external quantum efficiencies of 21.4% and 10.0% with peak maximums at 620 and 702 nm, confirming their suitability in making phosphorescent OLED devices.
Abstract
Efficient saturated red and near-infrared (NIR) emissive materials are needed in the development of organic light-emitting diodes (OLEDs), with applications extending beyond flat panel displays and lighting luminaries. Toward this aim, a series of bis-tridentate Ir(III) complexes (3a ‒ 3c and 4a ‒ 4c) are designed and synthesized, showing emission spanning the region of 601‒694 nm in degassed toluene. Their emission tuning is mainly achieved using monoanionic chromophoric chelates, L1H for red and L2H for deep-red and NIR, where the extended π-conjugation and electron deficient N atoms are introduced synergistically. Moreover, three ancillary chelates, X1H2
, X2H2
, and X3H2
, delivered a secondary influence via varied donor strength to the central Ir(III) atom. The resulting red and deep-red OLED devices exhibit maximum (max.) external quantum efficiencies (EQEs) of 21.4% and 18.1% with peak maximum at 620 and 666 nm, respectively. More impressively, the device based on 4b delivers a NIR emission peak maximum at 702 nm with a maximum EQE of 10.0%.
17 Oct 16:17
by P. Keerthika,
Rajendra Kumar Konidena
The recent advances in narrowband long-wavelength (> 550 nm) emissive multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters are highlighted in this review from the perspective of molecular design, photophysical properties, and electroluminescence performances in organic light-emitting diodes (OLEDs). MR-TADF materials that enable high-efficiency and high-color-purity electroluminescence will make significant contribution as a key technology for ultrawide-color-gamut OLEDs.
Abstract
Over the past decade, thermally activated delayed fluorescence (TADF) emitters have garnered tremendous impetus because of their ability to harvest 100% excitons for the light emission in organic light emitting diodes (OLEDs). However, despite their superior external quantum efficiencies (> 35%), the broad emission spectra with associated full-width-at-half maximum (FWHM > 70 nm) present a limiting factor that must be solved. Recently, multiple-resonance TADF (MR-TADF) materials based on the heteroatom doped polyaromatic hydrocarbons have gained astonishing attention owing to their remarkable narrowband emission (FWHM < 30 nm). However, emission of the majority of reported MR-TADF emitters falls in the blue/green region, which inevitably jeopardizes their application in full-color OLEDs. Therefore, there is an urgent need to develop the new molecular designs for expanding the color-gamut of MR-TADF emitters, i.e., λ
em > 550 nm without compromising the narrowband emission. To the best of current knowledge, no detailed reviews focusing on the different design strategies for producing long-wavelength (> 550 nm) MR-TADF emitters have been reported to date. To this end, a review highlighting the recent design advances for constructing long-wavelength MR-TADF emitters is presented, and their photophysics and OLED performance is discussed. Finally, the current status and future prospects of long-wavelength MR-TADF materials are discussed.
17 Oct 16:02
Chem. Commun., 2023, 59,13058-13061
DOI: 10.1039/D3CC03892K, Communication
Kyoung-Rok Kim, Jiwoo Kim, Jinrok Oh, Joohoon Kim, Jong-In Hong
Dimethylaminonaphthalene-oxazaborine donor–acceptor molecules were developed as efficient electrochemiluminescent luminophores with tunable intramolecular charge transfer.
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17 Oct 16:00
by Youhui Zhang,
Jiawei Deng,
Shiyong You,
Xuexiang Huang,
Jiabin Liu,
Yujun Cheng,
Bin Huang,
Xi Chen,
Zhe Sun,
Changduk Yang,
Qian‐Yong Cao,
Feiyan Wu,
Lie Chen
In this study, two novel small molecular of ZH1 and ZH2 are developed for organic solar cells (OSCs). It is observed that precise manipulation of end groups of acceptors can simultaneously optimize the morphology and improve the efficiency, stability, promoting the development of the high-performance OSCs.
Abstract
Introducing the guest materials into binary active layer to construct ternary organic solar cells (OSCs) is widely used to improve device performance. Nevertheless, designing the guest materials is a challenging task. Herein, asymmetric alloy acceptor strategy guided by similarity principle to design the guest materials is employed. Two small molecular acceptors (ZH1 with symmetric end groups and ZH2 with asymmetric end groups) with the same skeleton to the host acceptor are synthesized and compared. Compared to symmetric ZH1, asymmetric ZH2 delivers a remarkably higher efficiency (3.86% vs 13.03%) when paired with PM6, benefiting from the larger dipole moment to facilitate charge dynamics and more favorable morphology. More importantly, by introducing ZH1 and ZH2 as the guest materials into the PM6:BTP-eC9 blend, both ZH1 and ZH2 well alloy with acceptor BTP-eC9 due to the similar skeleton, not only providing a complementary absorption, but also optimizing and stabilizing the blend morphology. Notably, the asymmetric alloy acceptor distinctly outperforms symmetric alloy acceptor, PM6:BTP-eC9:ZH2-based device achieves an outstanding efficiency of 18.75% with better stability and reduced non-radiative energy loss. Therefore, developing asymmetric alloy acceptor is an effective strategy to develop high-performance and stable OSCs.
17 Oct 15:59
by Xueying Shi,
Bing Xiao,
Xiaodan Xu,
Yixuan Pan,
Jiajia Xiang,
Shiqun Shao,
Zhuxian Zhou,
Feihe Huang,
Jianqing Gao,
Nigel K. H. Slater,
Youqing Shen,
Jianbin Tang
A two-pronged strategy by combining cryo-shocked M1 macrophages (CSM1) and CD47-targeted lonidamine nanodrugs (CLNDN) is developed. CSM induce durable polarization of TAMs into immunostimulatory M1 phenotypes through the TLR2/MAPK signaling and CLNDN trigger tumor-specific pyroptosis through the caspase-3/GSDME pathway. This combination can synergically revert tumor immunosuppression, provoke potent antitumor immunity, and induce long-term immune memory against tumor metastasis and recurrence.
Abstract
Therapeutics targeting immune checkpoints have achieved astonishing clinical success in cancer treatment. However, these therapies can hardly adapt to immunologically “cold” tumors featuring insufficient and exhausted tumor-infiltrating lymphocytes as well as low immunogenicity. Herein, a two-pronged strategy is presented by combining cryo-shocked M1 macrophages (CSMs) and CD47-targeted lonidamine nanodrugs (CLNDN) for reprograming the immunosuppressive tumor microenvironment (TME). CSMs induce durable polarization of tumor-associated macrophages (TAMs) into the immunostimulatory M1 phenotype through the TLR2/MAPK signaling and also elevate CD47 expression in tumor cells, which in turn facilitates the targeted delivery of CLNDN into tumor cells. CLNDN trigger tumor cell-specific pyroptosis through the caspase-3/GSDME pathway and lead to the release of damage-associated molecular patterns. Consequently, the combination of CSM and CLNDN synergistically boosts immune infiltration and tumor cell immunogenicity within the TME, effectively reverting tumor immunosuppression. This combination achieves potent antitumor effects and induces long-term immune memory against tumor metastasis and recurrence. This work demonstrates for the first time TAM polarization by using cryo-shocked macrophages and highlights its coordination with tumor pyroptosis for igniting tumor immunity, opening up a new avenue for robust cancer immunotherapy.
17 Oct 15:58
by Tao Jia,
Jiarui Du,
Jiani Yang,
Yang Li,
Tymish Y. Ohulchanskyy,
Xikui Fang,
Guanying Chen
A facile hydrothermal strategy is employed to construct a core-shell heterostructure sonosensitizer comprising metalloporphyrin (Fe-TCPP) metal organic frameworks (MOFs) and bright DSNPs (NaErF4:Yb@NaLuF4). The coordination of Fe3+ into the macrocycle of TCPP at the MOFs shell is confirmed resulting in a marked decrease in TCPP phosphorescence and a significant increase in singlet oxygen generation, and the subsequent reduction of Fe3+ by GSH facilitates the restoration of DSNPs at 1525 nm, thereby significantly augmenting the generation of reactive oxygen species and enabling real-time monitoring of sonodynamic therapy.
Abstract
Noninvasive sonodynamic therapy (SDT) shows promise for brain glioma treatment due to deep tissue-penetrating capabilities (>10 cm) of ultrasound and high spatial resolutions. Yet, this technique is hindered by inefficient production of reactive oxygen species (ROS), resulting from the hypoxic tumor microenvironment (TME), high level of ROS scavenger glutathione (GSH), and the inability to visualize glioma in vivo for precise treatment management and monitoring in current sonosentizers. To address these challenges, we fabricated a core-shell heterostructure sonosensitizer (labeled as DFM), in which meso-tetra (4-carboxyphenyl) porphine (TCPP) porphyrin metal-organic frameworks (MOF, PCN-224(Fe)) serve as a porous shell to contain approved chemotherapeutics sorafenib (SRF) to effectively inhibit GSH synthesis, while NaErF4:Yb@NaLuF4 nanoparticles as the core provide TME-responsive NIR IIb (≈1500–1800 nm) luminescence at 1525 for precise optical imaging. Coordination of Fe3+ into the macrocycle of TCPP at the MOFs shell is found to, besides triggering ferroptosis, reduce TCPP phosphorescence (23% decrease) and increase the triplet state (T
1) oxygen quenching, substantially promoting the singlet oxygen generation (2.6-fold increase). Furthermore, GSH in TME facilitates the reduction of Fe3+ to Fe2+, thereby eliminating the luminescence quenching of Fe3+ and augmenting the NIR IIb luminescence of Er3+ (5-fold increase) for nanoagents accumulation imaging in intracranial glioma, realizing dynamical monitoring of SDT processes. Compared to control groups, in vitro and in vivo experiments confirm the effective ROS generation and results in a 6-fold volume reduction of brain gliomas, reaching a survival rate of 80% at 30 days posttreatment.
17 Oct 10:44
Chem. Sci., 2023, 14,12246-12254
DOI: 10.1039/D3SC04264B, Edge Article
Open Access
Xiu-Fang Song, Chenglin Jiang, Nengquan Li, Jingsheng Miao, Kai Li, Chuluo Yang
Red and deep-red emitters exhibiting thermally activated delayed fluorescence (TADF) from through-space charge transfer (TSCT) excited states have been developed by manipulating the intramolecular cofacial donor–acceptor interactions.
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24 Sep 19:16
by Cuihong Chen,
Zhenxing Yang,
Congyang Mao,
Liguo Jin,
Shuilin Wu,
Yufeng Zheng,
Zhenduo Cui,
Zhaoyang Li,
Yu Zhang,
Shengli Zhu,
Hui Jiang,
Xiangmei Liu
This work prepares novel curcumin sonosensitizers cationic starch modified curcumin nanoparticles through hydrogen bonding with methyl methacrylate and improved water solubility, resulting in decreased ΔE and ΔE
S-T and increased spin−orbital coupling values. These play a vital role in promoting triplet-state formation rates, thereby promoting power generation of reactive oxygen species capacity. Combined with targeting to realize rapid sterilization without antibiotics.
Abstract
Drugs treatment including antibiotics or herbal medicines cannot cure osteomyelitis effectively accompanied by drug-resistance bacteria and even amputation after long-term debridement. Herein, a materioherbological strategy is utilized to construct a smart nanovector of cationic starch (CS) modified curcumin nanoparticles (CS@Cur NPs) for treating methicillin-resistant Staphylococcus aureus (MRSA) induced osteomyelitis. On the one hand, CS modification can reduce the π–π accumulation of curcumin to endow the nanocomposite with excellent water solubility. On the other hand, the hydroxyl group in the curcumin is hydrogen-bonded to the carbonyl group in the monomer (methyl methacrylate, MMA) of CS, resulting in a decrease in both the bandgap (between the highest and lowest occupied molecular orbitals, labeled as ΔE) and the S1–T1 energy gap (ΔE
S-T) while the spin–orbital coupling (SOC) values increase, which benefits the formation of triplet-state molecules under ultrasonic irradiation, significantly improving the yields of reactive oxygen species (ROS) capacity. The CS@Cur NPs nanocomposite constructed in this paper produced a large number of ROS synergic targeting effects under continuous 15 min ultrasonic irradiation, the clearance rate of MRSA infection induced osteomyelitis in rats can be as high as 99.93%. This study provides a new therapeutic strategy for the treatment of osteomyelitis induced by pathogenic bacteria.
12 Sep 04:40
by Shi Tang,
John Marques dos Santos,
Joan Ràfols‐Ribé,
Jia Wang,
Eli Zysman‐Colman,
Ludvig Edman
The functional incorporation of a multi-resonance thermally activated delayed fluorescence (MR-TADF) emitter into a light-emitting electrochemical cell (LEC) is reported. This designed MR-TADF LEC delivers narrowband and bright blue emission, with a full-width-at-half-maximum of 31 nm and 500 cd m−2, respectively, at a high external quantum efficiency of 3.8%.
Abstract
Organic semiconductors that emit by the process of multi-resonance thermally activated delayed fluorescence (MR-TADF) can deliver narrowband and efficient electroluminescence while being processable from solvents and metal-free. This renders them attractive for use as the emitter in sustainable light-emitting electrochemical cells (LECs), but so far reports of narrowband and efficient MR-TADF emission from LEC devices are absent. Here, this issue is addressed through careful and systematic material selection and device development. Specifically, the authors show that the detrimental aggregation tendency of an archetypal rigid and planar carbazole-based MR-TADF emitter can be inhibited by its dispersion into a compatible carbazole-based blend host and an ionic-liquid electrolyte, and it is further demonstrated that the tuning of this active material results in a desired balanced p- and n-type electrochemical doping, a high solid-state photoluminescence quantum yield of 91%, and singlet and triplet trapping on the MR-TADF guest emitter. The introduction of this designed metal-free active MR-TADF material into a LEC, employing air-stabile electrodes, results in bright blue electroluminescence of 500 cd m−2, which is delivered at a high external quantum efficiency of 3.8% and shows a narrow emission profile with a full-width-at-half-maximum of 31 nm.
12 Sep 04:40
by Yuzhong Chen,
Zeng Wu,
Lu Ding,
Shuixin Zhang,
Zekun Chen,
Wenhao Li,
Yan Zhao,
Yang Wang,
Yunqi Liu
How the molecular packing of Y-series non-fullerene acceptors fundamentally determines their charge-transport properties is clarified by manipulating their crystal stacking via sidechain engineering. Therefore, the all-branched-chains-substituted derivative, namely 1OBO-2, exhibits single crystal structure with a favorable 3D interpenetrating porous network. It thus results in an excellent electron mobility of 1.42 cm2 V−1 s−1 in organic single-crystal transistors.
Abstract
Y-series non-fullerene acceptors (NFAs) have achieved great progress in organic solar cells (OSCs). Most research attention is currently paid to their molecular engineering to improve the efficiency of OSCs. However, as n-type organic semiconductors, the relationship between their molecular packing structures and charge transport properties is mostly ignored. Herein, it is clarified how the molecular packing of Y-series NFAs fundamentally determines their charge transport properties by manipulating their crystal stacking via sidechain engineering. Therefore, branched alkyl/alkoxy substitutions are taken on a reference NFA (Y6-1O), affording three derivatives, namely 1OBO-1, 1OBO-2, and 1OBO-3. Results show that while the replacement of branched alkyl/alkoxy sidechains has little impact on optical properties and energy levels, it can change crystal stacking motifs significantly. The single crystal of Y6-1O with all linear sidechains forms a 2D-brickwork structure and shows lower mobility. In contrast, 1OBO-2 with all branched sidechains exhibits a favorable 3D interpenetrating porous network, displaying an electron mobility of 1.42 cm2 V−1 s−1 in single-crystal organic field-effect transistors (SC-OFETs). This value is among the highest for NFA-based n-type OFETs. This study not only reveals the fundamental structure–property relationships of Y-series NFAs, but also suggests the potential of Y-series NFAs for high-performance n-type organic semiconductors.
12 Sep 04:38
by Yu Zhang,
Dong Li,
Qihuan Li,
Yiwu Quan,
Yixiang Cheng
Chiral coassembled host materials are first constructed through a strong π–π stacking interaction using an achiral conjugated pyridine-based polymer acceptor doped with a chiral binaphthyl-based donor. Significantly, the chiral coassembly hosts promote an achiral phosphorescence emitter to achieve red circularly polarized electroluminescence at 620 nm with a high external quantum efficiency of 4.1% and large |g
EL| values of 0.014.
Abstract
Circularly polarized organic light-emitting diodes are of great significance in 3D displays. However, achieving circularly polarized electroluminescence (CP-EL) simultaneously with a large dissymmetry factor (g
EL) and high efficiency still remains a formidable challenge. Herein, a facile and efficient strategy is developed for improving the performance of CP-EL devices using device emitting layers of chiral coassembled helix nanofiber host materials. Chiral coassembled helix nanofiber host materials ((S-/R-2Cz)0.2-(PFpy)0.8) could be smartly constructed through intermolecular π–π stacking interactions between the achiral conjugated pyridine-based polymer acceptor (PFpy) and the chiral binaphthyl-based donor (S-/R-2Cz). Significantly, the resulting chiral coassembled hosts (S-/R-2Cz)0.2-(PFpy)0.8 greatly promote a commercially available achiral phosphorescence emitter to achieve solution-processed red CP-EL device performances at 620 nm with a high external quantum efficiency of 4.1% and a large |g
EL| value of 0.014.
12 Sep 04:37
by Fengbo Sun,
Xunchang Wang,
Ming Wan,
Zhitian Liu,
Yixuan Luo,
Jiajia Ren,
Xufan Zheng,
Thomas Rath,
Cong Xiao,
Tianyu Hu,
Gregor Trimmel,
Renqiang Yang
As an analog of D18-Cl, the new polymer donor D18-ChCl is designed by substituting the 2-ethylhexyl side chains with cyclohexyl-hexyl chain. Using PYF-T-o as the acceptor, the D18-ChCl blend realizes an interpenetrating network constituting of smaller phase separation, and higher miscibility and crystallinity. Such a morphology evolution reduces energy disorder and trap density, which ultimately boosts the power conversion efficiency from 12.3% to 17.1%.
Abstract
Reducing the trap density within organic solar cells is of vital importance to realize high power conversion efficiency (PCE); however, research focusing on this aspect is limited in all-polymer solar cells (All-PSCs). In this work, it is found that the trap density can be dramatically reduced by simultaneously obtaining high miscibility of donor and acceptor and ordered packing in blend films through substituting ethylhexyl with hybrid cyclohexyl-hexyl side chains in the design of the polymer donor. D18-ChCl with hybrid cyclohexyl-hexyl chains has a slightly lower aggregation behavior relative to the D18-Cl counterpart, but reveals synchronously higher miscibility and crystallinity in a blend with the acceptor PYF-T-o. Such a morphology evolution positively affects the electronic properties of the device—prolongs the carrier lifetime, facilitates exciton dissociation, and lowers the energy disorder. As a result, the All-PSC devices based on D18-ChCl exhibited a remarkable PCE of 17.1%, with a low trap density of 2.65 × 1015 cm−3, a low energy disorder of 47 meV as well as outstanding stability and mechanical durability. This result demonstrates that hybrid cyclohexyl-hexyl alkyl engineering delicately improves miscibility, drives low trap density, and refines device performance, which brings vibrancy to the All-PSC research field.
12 Sep 04:35
by Xiang Xu,
Qingya Wei,
Zhisheng Zhou,
Haozhe He,
Jingjing Tian,
Hin‐Lap Yip,
Yuang Fu,
Xinhui Lu,
Yonghua Zhou,
Yongfang Li,
Yingping Zou
A color-neutral semitransparent organic solar cell (ST-OSC) is fabricated using a new near-infrared acceptor BZO-4Cl. By some optimization strategies , as a consequence, the ST-OSC shows light utilization efficiency (LUE) of 4.02% and color rendering index (CRI) of 90.67%, which are among the best ST-OSCs with both LUE and CRI values.
Abstract
Semitransparent organic solar cells (ST-OSCs) can function as power-generating windows due to their ability to allow visible light go-through for human eyesight while absorbing low-energy photons in the near-infrared region for photocurrent generation. In this regard, effective ST-OSCs with high light utilization efficiency (LUE) and color rendering index (CRI) can be developed via a synergistic material and device engineering strategy. Herein, an A-DA'D-A acceptor BZO-4Cl is synthesized with an ultralow optical bandgap of 1.26 eV and bathochromically shifted absorption of roughly 60 nm with respect to Y6. Initially, the opaque devices using PTB7-Th as the donor show a high power conversion efficiency (PCE) of 14.12% , which can be listed as one of the highest efficiencies for the PTB7-Th-based OSCs so far. Then, through these efforts of optimizations in the bulk-heterojunction(BHJ) composition, top electrodes and anti-reflection layer, the cutting-edge ST-OSC demonstrates a high LUE of 4.02%, and a CRI of 90.67%, making it one of the best-performing ST-OSCs with both high LUE and CRI values. These results indicate that the ST-OSCs presented in this study have significant potential for use in applications that possess transparent visible light and energy-generation functions.
12 Sep 04:35
by Jun Yong Kim,
Sang Youn Lee,
Kwan Hyun Cho,
Yun Seon Do
A novel optical design concept is proposed for a dual-microcavity structure that controls high-order modes with the same cavity length of electroluminescent (EL) devices for each red, green, and blue (RGB) subpixel. The structure can overcome the challenges of EL devices, such as different electrical characteristics and complex patterning for each subpixel due to different cavity lengths of RGB wavelengths.
Abstract
Microcavity structures are used in inorganic-, organic-, quantum-dot-, and perovskite-based electroluminescent (EL) devices to advance next-generation displays. However, there are difficulties in controlling electrical characteristics and patterning processes for producing different thicknesses for each red, green, and blue (RGB) subpixel, and the issues are more challenging in the high-resolution display for future realistic media. Here, a novel design method is presented for a dual-microcavity structure that controls high-order modes of a second cavity stacked on top of EL devices with the same cavity length for each subpixel to produce multiple peaks at RGB resonant wavelengths. The dual-microcavity effect demonstrated by top-emitting organic light-emitting diodes (OLEDs) can be conveniently fabricated via in situ deposition. By modulating the high-order modes, the spectral characteristics of each RGB dual-microcavity top-emitting OLED (DMTOLED) are manipulated while its electrical properties are maintained. Green DMTOLED exhibits a maximum luminance of 2.075 × 105 cd m−2, allowing applications not only for commercialized displays but also for outdoor augmented reality and automotive displays. Furthermore, dual-microcavity structures with narrow spectral bandwidths can be applied to next-generation EL devices for more realistic media. The method is expected to be applied industrially, promoting the advancement of EL devices for next-generation displays.
12 Sep 04:34
by Guping Zhang,
Xunxun Li,
Dongyun Chen,
Najun Li,
Qingfeng Xu,
Hua Li,
Jianmei Lu
A cadmium sulfide@covalent triazine frameworks (CdS@CTF-HUST-1) core–shell S-scheme heterojunction photocatalyst is successfully fabricated for CO2 adsorption and photocatalytic conversion. Benefiting from the integrated strong internal electric field and adsorption effect, the designed CdS@CTF-HUST-1 photocatalyst demonstrates dramatically boosted CO2-to-CO reduction performance. This study will provide a reference for designing advanced core–shell heterostructure systems for adsorption-photocatalytic CO2 conversion.
Abstract
Solar-driven photocatalytic conversion of carbon dioxide (CO2) into carbon-neutral fuels is of significance for energy sustainability. The critical challenges in this process are high charge carrier recombination and low CO2 adsorption capacity. Here, by integrating porous covalent triazine frameworks (CTFs) with cadmium sulfide (CdS) nanospheres, a CdS@CTF-HUST-1 heterojunction photocatalyst with core–shell structure is developed for CO2-to-CO conversion. Experimental investigations combined with density functional theory simulations reveal that the formation of an internal electric field provides the driving force for accelerating S-scheme charge transfer, resulting in enhanced separation and utilization efficiency of charge carriers in photocatalysis. Together with the improved CO2 adsorption capacity contributed by the porous structure of the CTF-HUST-1 shell, the CdS@CTF-HUST-1 heterojunction photocatalyst gives an impressive CO yield rate of 168.77 µmol g−1 h−1 with high selectivity. This research furnishes a feasible strategy to construct highly active core–shell composite photocatalysts for optimizing CO2 adsorption and conversion.
12 Sep 04:33
by Shuaishuai Yan,
Zhan Wang,
Fengxiang Liu,
Hangyu Zhou,
Kai Liu
A supramolecular polyurethane material reinforced by aromatic donor–acceptor (D–A) charge-transfer interactions is utilized as electrolyte matrix with high stiffness, excellent toughness, and unique mechanical energy dissipation capacity. This study highlights the importance of the comprehensive mechanical properties of polymer electrolytes and the stable electrolyte/electrode interface for high-performance solid-state lithium metal batteries.
Abstract
Polymer electrolytes have great potential to realize solid-state lithium metal batteries with high energy density and intrinsic safety. However, the poor mechanical strength and uncontrolled electrolyte/electrode interface cannot guarantee the stable operation during long-term cycling. Herein, a supramolecular polyurethane material reinforced by aromatic charge-transfer interactions is synthesized as electrolyte matrix with high stiffness, excellent toughness, and unique mechanical energy dissipation capacity. The optimized electrolyte network can dynamically adapt to the volume fluctuating Li metal and, importantly, eliminate stress-concentrating behavior under deformed state. As a result, the Li/Li symmetric cells can stably work for more than 3500 h without short circuit. And the LiFePO4/Li batteries show superior electrochemical performance over 1200 cycles with a capacity retention of 95.4% at 0.33 C. The supramolecular approach to tune the mechanical properties of the polymers is believed to provide a new strategy for designing solid electrolytes with desirable comprehensive mechanical properties for solid-state batteries.
12 Sep 04:32
by Hao Liu,
Yan Fu,
Ben Zhong Tang,
Zujin Zhao
All-fluorescence white organic light-emitting diodes with record-high electroluminescence efficiency and color rendering index and excellent operational stability are achieved by interlayer-sensitizing strategy assisted by thermally activated delayed fluorescence electron-capturing agent.
Abstract
As a promising next-generation lighting technology, all-fluorescence white organic light-emitting diodes (WOLEDs) have advanced rapidly but still face the formidable challenge of achieving high efficiencies and high color quality simultaneously. Herein, an interlayer sensitization strategy assisted by electron-capturing agent with thermally activated delayed fluorescence (TADF) is proposed for the fabrication of high-performance all-fluorescence WOLEDs. The proof-of-concept three-color devices with an interlayer-sensitizing configuration are designed, and a low concentration of TADF electron-capturing agent is codoped with a red conventional fluorescence (CF) emitter to reduce exciton loss. The major energy transfer from TADF sensitizing layer to red CF emitter combined with the supplementary energy transfer from TADF electron-capturing agent to CF emitter can successfully increase exciton utilization. The synergistic effect endows the three-color all-fluorescence WOLEDs with high efficiencies, high color quality, and improved efficiency stability and operational stability, simultaneously. The resultant WOLEDs successfully attain remarkable external quantum efficiency of 31.0%, outstanding color rendering index of 93 and long operational lifetime. The record-beating comprehensive performances of these WOLEDs strongly demonstrate the great potential of the proposed strategy for the exploration of high-performance all-fluorescence WOLEDs.
12 Sep 04:26
Chem. Sci., 2023, 14,9885-9891
DOI: 10.1039/D3SC03083K, Edge Article
Open Access
Marius Reinhold, Justin Steinebach, Christopher Golz, Johannes C. L. Walker
Crossed [2 + 2] cycloaddition yields bicyclo[2.1.1]hexanes with 11 different substitution patterns. ortho-, meta- and polysubstituted benzene bioisosteres, and structures with substituent patterns that go beyond aromatic chemical space can be prepared.
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12 Sep 04:24
Chem. Sci., 2023, 14,11040-11044
DOI: 10.1039/D3SC03242F, Edge Article
Open Access
R. Jeyaseelan, M. Utikal, C. G. Daniliuc, L. Næsborg
A commercially available upconversion pair is applied to promote a photocyclization for the synthesis of bioisosteres using green light irradiation. The reaction concept is enabled to run in water without oxygen removal by a micellar medium.
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