25 Aug 15:03
Mater. Horiz., 2021, 8,2335-2342
DOI: 10.1039/D1MH00868D, Communication
Xuan Liu, Yang Liu, Yongfeng Ni, Ping Fu, Xuchao Wang, Qing Yang, Xin Guo, Can Li
A highly fluorescent molecule was introduced into ternary organic solar cells to enhance PL emission and EQEELvia the FRET to acceptor component, reducing non-radiative recombination energy loss and thus improving open-circuit voltage up to 41 mV.
The content of this RSS Feed (c) The Royal Society of Chemistry
25 Aug 11:58
Energy Environ. Sci., 2021, 14,4555-4563
DOI: 10.1039/D1EE00687H, Paper
Xiaojun Li, Siwei Luo, Huiliang Sun, Herman Ho-Yung Sung, Han Yu, Tao Liu, Yiqun Xiao, Fujin Bai, Mingao Pan, Xinhui Lu, Ian Duncan Williams, Xugang Guo, Yongfang Li, He Yan
Via designing of medium band-gap non-fullerene acceptors (NFAs) based on Y6, the indoor OPVs achieve the PCE of 25.1% at 1000 lux illumination. Furthermore, the results show that non-planar NFAs can also achieve outstanding performance.
The content of this RSS Feed (c) The Royal Society of Chemistry
25 Aug 11:56
by Siying Li,
Xin Yuan,
Qilin Zhang,
Bin Li,
Yuxiang Li,
Jianguo Sun,
Yifeng Feng,
Xuning Zhang,
Zang Wu,
Huan Wei,
Mei Wang,
Yuanyuan Hu,
Yuan Zhang,
Han Young Woo,
Jianyu Yuan,
Wanli Ma
Two narrow-bandgap block copolymers PBDB-T-b-PIDIC2T and PBDB-T-b-PTY6 are designed and synthesized for single-component polymer solar cells, and a record-high efficiency of 8.64% is obtained. Moreover, these block copolymers exhibit relatively small energy loss and improved storage stability under both ambient condition and continued 80 °C thermal stresses for over 1000 h.
Abstract
Two narrow-bandgap block conjugated polymers with a (D1–A1)–(D2–A2) backbone architecture, namely PBDB-T-b-PIDIC2T and PBDB-T-b-PTY6, are designed and synthesized for single-component organic solar cells (SCOSCs). Both polymers contain same donor polymer, PBDB-T, but different polymerized nonfullerene molecule acceptors. Compared to all previously reported materials for SCOSCs, PBDB-T-b-PIDIC2T and PBDB-T-b-PTY6 exhibit narrower bandgap for better light harvesting. When incorporated into SCOSCs, the short-circuit current density (J
sc) is significantly improved to over 15 mA cm−2, together with a record-high power conversion efficiency (PCE) of 8.64%. Moreover, these block copolymers exhibit low energy loss due to high charge transfer (CT) states (E
ct) plus small non-radiative loss (0.26 eV), and improved stability under both ambient condition and continuous 80 °C thermal stresses for over 1000 h. Determination of the charge carrier dynamics and film morphology in these SCOSCs reveals increased carrier recombination, relative to binary bulk-heterojunction devices, which is mainly due to reduced ordering of both donor and acceptor fragments. The close structural relationship between block polymers and their binary counterparts also provides an excellent framework to explore further molecular features that impact the photovoltaic performance and boost the state-of-the-art efficiency of SCOSCs.
25 Aug 11:51
by Bingqing Liu,
Jian Jiao,
Wan Xu,
Miya Zhang,
Peng Cui,
Zhengqing Guo,
Yibin Deng,
Huabing Chen,
Wenfang Sun
A far-red/near-infrared (NIR)-absorbing neutral Ir(III) complex (BODIPY-Ir) bearing the distyryl boron dipyrromethene motif and its encapsulated micelles (Micelle-Ir) are reported for potent photodynamic/photothermal therapy (PDT/PTT) against aggressive tumors. Micelle-Ir demonstrates a remarkable therapeutic efficacy against primary breast and metastatic lung tumors through bifunctional PDT/PTT damage in a cooperative manner.
Abstract
A critical issue in photodynamic therapy (PDT) is inadequate reactive oxygen species (ROS) generation in tumors, causing inevitable survival of tumor cells that usually results in tumor recurrence and metastasis. Existing photosensitizers frequently suffer from relatively low light-to-ROS conversion efficiency with far-red/near-infrared (NIR) light excitation due to low-lying excited states that lead to rapid non-radiative decays. Here, a neutral Ir(III) complex bearing distyryl boron dipyrromethene (BODIPY-Ir) is reported to efficiently produce both ROS and hyperthermia upon far-red light activation for potentiating in vivo tumor suppression through micellization of BODIPY-Ir to form “Micelle-Ir”. BODIPY-Ir absorbs strongly at 550–750 nm with a band maximum at 685 nm, and possesses a long-lived triplet excited state with sufficient non-radiative decays. Upon micellization, BODIPY-Ir forms J-type aggregates within Micelle-Ir, which boosts both singlet oxygen generation and the photothermal effect through the high molar extinction coefficient and amplification of light-to-ROS/heat conversion, causing severe cell apoptosis. Bifunctional Micelle-Ir that accumulates in tumors completely destroys orthotopic 4T1 breast tumors via synergistic PDT/photothermal therapy (PTT) damage under light irradiation, and enables remarkable suppression of metastatic nodules in the lungs, together without significant dark cytotoxicity. The present study offers an emerging approach to develop far-red/NIR photosensitizers toward potent cancer therapy.
23 Aug 02:17
by Mengqi Cui, Na Li, Yuying Wang, Yuting Li, Xia Tian, Xingchen Zhang, Wenting Wang, Zhongmin Liu, Qikun Rong, Xingsen Gao, Guofu Zhou, and Li Nian
ACS Applied Materials & Interfaces
DOI: 10.1021/acsami.1c06329
23 Aug 02:17
by Yuanhui Sun, Bochen Liu, Yue Guo, Xi Chen, Yi-Ting Lee, Zhao Feng, Chihaya Adachi, Guijiang Zhou, Zhao Chen, and Xiaolong Yang
ACS Applied Materials & Interfaces
DOI: 10.1021/acsami.1c06148
23 Aug 02:17
by Ibrahim Oladayo Raji▽, Shuguang Wen▽, Yonghai Li, Da Huang, Xiaoyan Shi, Aziz Saparbaev, Chuantao Gu, Chunming Yang, and Xichang Bao
ACS Applied Materials & Interfaces
DOI: 10.1021/acsami.1c07822
王磊, 以昇陳 and 3 others like this
23 Aug 02:17
by Masaaki Mitsui, Yushiro Nakagome, Yoshiki Niihori, Shota Inoue, Yutaka Fujiwara, and Kenji Kobayashi
ACS Applied Materials & Interfaces
DOI: 10.1021/acsami.1c08431
23 Aug 02:16
by Sonam Saxena, Philipp Marlow, Jegadesan Subbiah, Alexander Colsmann, Wallace W. H. Wong, and David J. Jones
ACS Applied Materials & Interfaces
DOI: 10.1021/acsami.1c07219
08 Aug 16:35
by Linyu Cao,
Zhi‐Qiang Zhu,
Kody Klimes,
Jian Li
A tetradentate Pd(II) complex, i.e., Pd3O8-Py5, exhibiting efficient aggregate emission is developed through judicious ligand design. The optimized organic light-emitting diode device using Pd3O8-Py5 aggregates exhibits a peak EQEair of 37.3% and a peak EQEair+sub of 67.4% with reduced efficiency roll-off, and a long measured LT95 lifetime (time to 95% of the initial luminance) of over 500 h with an initial brightness of 17 304 cd m−2.
Abstract
Phosphorescent molecular aggregates show promise in realizing efficient and stable organic light-emitting diodes (OLEDs) operating at high brightness level, which is highly desired for future lighting and display applications. Herein, four tetradentate Pd(II) complexes are prepared with judicious ligand design, and their electrochemical and photophysical properties are thoroughly examined. The studies indicate that slight structural changes of ligands can modify the hole and electron transporting capabilities, and alter the horizontal emitting dipole ratios of aggregates in amorphous film, the latter of which are sensitive to the thin-film deposition conditions including the deposition rate and the choice of the templating layer. An optimized OLED device using Pd3O8-Py5 aggregates exhibits a peak external quantum efficiency (EQE) of 37.3% and a reduced efficiency roll-off with high EQEs of 36.0% and 32.5% at 1000 and 10 000 cd m−2, respectively. Moreover, such an efficient device demonstrates a long measured LT95 (time to 95% of the initial luminance) lifetime of over 500 h with an initial brightness of 17 304 cd m−2 corresponding to an estimated LT95 lifetime of 48 246 h at 1000 cd m−2.
06 Aug 10:49
by Xuancheng Fu,
Yiming Huang,
Hao Zhao,
Endong Zhang,
Qi Shen,
Yufei Di,
Fengting Lv,
Libing Liu,
Shu Wang
A new strategy for near-infrared-light remote-controlled activation of cancer immunotherapy is developed using photothermal conjugated polymer nanoparticles (CPNs). The CPNs serve as a photo–heat nanotransducer to trigger the gene transcription of the IFN-γ cytokine. The secreted IFN-γ can sufficiently elicit surrounding tumor-associated macrophages activation followed by cancer cell killing by immunotherapy.
Abstract
Remote control of the therapeutic process is an ideal strategy for maximizing efficacy and avoiding side effects, especially for cancer immunotherapy. Herein, a conjugated polymer nanoparticles (CPNs)-mediated optogenetic system for in situ activation of immunotherapy under near-infrared laser irradiation is reported. This system is composed of photothermal CPNs and interferon-gamma (IFN-γ) plasmid driven by heat shock promoter HSP70. The photothermally responsive CPNs serve as a photo–heat nanotransducer to trigger the gene transcription of IFN-γ cytokine. The secreted IFN-γ from cancer cells can sufficiently elicit surrounding tumor-associated macrophages activation through IFN-γ-JAK-STAT1 transcription-factor signaling pathway and finally induce cancer cell killing by immunotherapy. Therefore, this synergetic optogenetic system provides a promising approach to remotely control the process of cancer immunotherapy.
05 Aug 02:08
by Chen Zhang,
Dongdong Zhang,
Zhengyang Bin,
Ziyang Liu,
Yuewei Zhang,
Hyuna Lee,
Jang Hyuk Kwon,
Lian Duan
Color-tunable white organic light-emitting diodes with hole-trapping thermally activated delayed-fluorescence-sensitized emissions realize significant Commission Internationale de l'Eclairage coordinates and correlated color temperature shifts from (0.40, 0.47) and 4088 K at 100 cd m−2 to (0.27, 0.33) and 9269 K at 5000 cd m−2, with a reported maximum external quantum efficiency of 30.7% and long lifetime of over 20 000 h at 80% of the initial luminance.
Abstract
White organic light-emitting diodes (WOLEDs) with high efficiencies and tunable colors attracts considerable interest from the industry and academia. Thermally activated delayed-fluorescence (TADF) emitters can revolutionize such WOLED devices; however, they still suffer from poor performances. In this study, an advanced double-emissive-layer device architecture capable of hole-trapping TADF-sensitized emissions is proposed to not only achieve a recombination zone shift for the tunable colors but also accelerate exciton emission dynamics for high efficiency and alleviated roll-off. The proof-of-concept WOLEDs exhibit significant shifts in their Commission Internationale de l'Eclairage (CIE) coordinates and correlated color temperatures from (0.40, 0.47) and 4088 K at 100 cd m−2 to (0.27, 0.33) and 9269 K at 5000 cd m−2. Additionally, the maximum external quantum efficiency (EQE) reaches 30.7% and remains >25% over a wide luminance range of 500–5000 cd m−2, along with an extended LT80 of over 20 000 h at an initial luminance of 100 cd m−2. This is the first time that all-fluorescent WOLEDs have been used to realize an EQE exceeding 30%, thereby establishing a new benchmark in this field.
15 Jul 08:14
by Shenjie Wu, Daming Ren, Kang Zhou, Hai-Lun Xia, Xiao-Yuan Liu, Xiaotai Wang, and Jing Li
Journal of the American Chemical Society
DOI: 10.1021/jacs.1c04810
30 Jun 11:26
by Yogajivan Rout, Chiara Montanari, Erika Pasciucco, Rajneesh Misra, and Benedetta Carlotti
Journal of the American Chemical Society
DOI: 10.1021/jacs.1c04173
30 Jun 11:24
by Seongsoo Kang, Taeyeon Kim, Yongseok Hong, Frank Würthner, and Dongho Kim
Journal of the American Chemical Society
DOI: 10.1021/jacs.1c03276
24 Jun 06:38
by Mingyu Jeong,
Jiyeon Oh,
Yongjoon Cho,
Byongkyu Lee,
Seonghun Jeong,
Sang Myeon Lee,
So‐Huei Kang,
Changduk Yang
![Triisopropylsilyl-Substituted Benzo[1,2-b:4,5-c′]dithiophene-4,8-dione-Containing Copolymers with More Than 17% Efficiency in Organic Solar Cells](https://onlinelibrary.wiley.com/cms/asset/7c36539f-b8a2-469f-a541-5d30eb131548/adfm202102371-gra-0001-m.png)
Copolymer series with varying contents of triisopropylsilyl-substituted benzo[1,2-b:4,5-c′]dithiophene-4,8-dione are synthesized and characterized. Using them as donors for bulk-heterojunction organic solar cells, a high power conversion efficiency of 17.01% is achieved from optimal composition of monomers with balanced charge transport, enhanced charge generation/dissociation kinetics, and minimized total energy and recombination losses.
Abstract
Considering the special functions of fused-ring aromatic building blocks and Si-atom in high-performance donor–acceptor-conjugated materials at the same time, herein the synthesis of a novel fused-ring tricyclic heterocycle, triisopropylsilyl-substituted benzo[1,2-b:4,5-c′]dithiophene-4,8-dione (iBDD-Si), an isomer of well-known benzo[1,2-c:4,5-c′]dithiophene-4,8-dione is presented. The iBDD-Si-based copolymer series (PM6, PM6-5Si, PM6-10Si, and PM6-15Si) is synthesized via Stille polymerization, revealing fine-tuned optical and electrochemical properties, and molecular packing with varying iBDD-Si contents in the backbone. Organic solar cells are fabricated by pairing the copolymer donors with nonfullerene acceptor N3 and characterized. High power conversion efficiency of more than 17% is achieved using the PM6-5Si-based solar cell, which is attributed to the balanced charge transport, enhanced charge generation/dissociation kinetics, and minimized total energy and recombination losses. It is demonstrated that iBDD-Si is a promising backbone toolbox for various high-performance conjugated materials.
24 Jun 06:37
by Jun Li,
Lijian Zuo,
Haotian Wu,
Benfang Niu,
Shiqi Shan,
Gang Wu,
Hongzheng Chen
This study develops a universal bottom interface modification method with diverse 2D spacers, which significantly enhance the device performance of inverted perovskite solar cells from 20.7% to 21.6%. The lift-off method is used to directly study the change of optoelectronic properties at the bottom interface and unveils the formation of 2D/3D heterojunction as the general mechanism underlying the device performance enhancement.
Abstract
Although the 2D spacer modification is widely studied in perovskite solar cells (PVSCs), the energy level alignment between the 2D/3D interfaces makes it unfavorable for top surface passivation in the inverted p-i-n device structure. To address this issue, the effect of bottom interface modification is studied with three representative 2D spacers, i.e., the Ruddlesden-Popper 2D spacer, Dion-Jacobson 2D spacer, and strong passivation 2D spacer, in inverted p-i-n PVSCs. After optimization, the PVSCs with these 2D spacer modifications universally exhibit the best efficiencies of ≈21.6%, which constitutes dramatic improvement compared to the control device (20.7%). By lifting off the perovskite layer, the optoelectronic properties of the bottom surface are studied, and the mechanism underlying the improved device performance is unveiled to be uniformly originated from the formation of 2D/3D heterojunction, where the cascade valence band facilitates the hole collection and electron back scattering field suppresses the charge recombination at the anode interface. Besides, the unencapsulated device retains 90% of initial efficiency after 30 days of storage in ambient air with a relative humidity of 30 ± 5%, indicating excellent stability against moisture and oxygen. This study provides insight into the bottom interface modification with diverse 2D spacers for high-performance p-i-n structured PVSC devices.
24 Jun 06:37
by Hao Lu,
Hui Jin,
Hao Huang,
Wenxu Liu,
Zheng Tang,
Jianqi Zhang,
Zhishan Bo
Replacing one of the chlorinated terminal groups with norbornyl-modified one endows the reported asymmetric acceptors with not only enhanced solubility but also more favorable morphology and higher EQEEL in the blend with PBDB-T. A power conversion efficiency of 16.82% with a J
sc over 26.5 mA cm−2 and a ΔV
nr of 0.18 V are realized, representing the state-of-the-art in PBDB-T based organic solar cells.
Abstract
Three asymmetric non-fullerene acceptors (LL2, LL3, and LL4) are designed and synthesized with one norbornyl-modified 1,1-dicyanomethylene-3-indanone (CBIC) terminal group and one chlorinated 1,1-dicyanomethylene-3-indanone (IC-2Cl) terminal group. The three-dimensional shape-persistent CBIC terminal group can effectively enhance the solubility and tune the packing mode of acceptors. Compared with their symmetric counterparts (LL2-2Cl, LL3-2Cl, and LL4-2Cl) bearing two IC-2Cl terminals, the asymmetric acceptors show improved solubilities, giving rise to enhanced crystallinity and favored nanomorphology for charge transport in the blend films with PBDB-T. Asymmetric acceptors based organic solar cells (OSCs) also show much lower voltage loss due to their higher E
CT and EQEEL values. Therefore, they exhibit 17−27% higher power conversion efficiency (PCE) than OSCs based on the corresponding symmetric acceptors. Among these six acceptors, LL3 with a central benzotriazole core shows the best PCE of 16.82% with an outstanding J
sc of 26.97 mA cm−2 and a low nonradiative voltage loss (ΔV
nr) of 0.18 V, the best values for PBDB-T based OSCs. The J
sc and ΔV
nr also represent the best reported for asymmetric non-fullerene acceptors-based OSCs to date. The results demonstrate that the combination of the unique CBIC terminal group with the asymmetric strategy is a promising way to enhance the performance of OSCs.
24 Jun 06:36
by Zhenye Wang,
Meichen Xu,
Zhilin Li,
Yerun Gao,
Lvpeng Yang,
Di Zhang,
Ming Shao
An intrinsically stretchable organic solar cell (OSC) with an efficiency of over 10% is achieved by the transfer printing method. The ductility of bulk heterojunction film is greatly improved to 20% by introducing polydimethylsiloxane additives, and intimated multilayer stacking is realized with the assistance of electrical adhesive D-Sorbitol. The stretchable OSC exhibits ultra-flexibility and superior stretchability without sacrificing the device performance.
Abstract
Stretchable organic solar cells (OSCs) simultaneously possessing high-efficiency and robust mechanical properties are ideal power generators for the emerging wearable and portable electronics. Herein, after incorporating a low amount of trimethylsiloxy terminated polydimethylsiloxane (PDMS) additive, the intrinsic stretchability of PTB7-Th:IEICO-4F bulk heterojunction (BHJ) film is greatly improved from 5% to 20% strain without sacrificing the photovoltaic performance. The intimate multi-layers stacking of OSCs is also realized with the transfer printing method assisted by electrical adhesive “glue” D-Sorbitol. The resultant devices with 84% electrode transmittance exhibit a remarkable power conversion efficiency (PCE) of 10.1%, which is among the highest efficiency for intrinsically stretchable OSCs to date. The stretchable OSCs also demonstrate the ultra-flexibility, stretchability, and mechanical robustness, which keep the PCE almost unchanged at small bending radium of 2 mm for 300 times bending cycles and retain 86.7% PCE under tensile strain as large as 20% for the devices with 70% electrode transmittance. The results provide a universal method to fabricate highly efficient intrinsically stretchable OSCs.
24 Jun 06:36
by Yang Shen,
Hai‐Yan Wu,
Yan‐Qing Li,
Kong‐Chao Shen,
Xingyu Gao,
Fei Song,
Jian‐Xin Tang
Synergistic manipulation of the whole electroluminescence process in blue perovskite light-emitting diodes has been proposed with an interfacial nucleation seeding scheme. Efficient and stable blue devices achieve a maximum external quantum efficiency of 27.5% and improved electroluminescent stability during operation.
Abstract
Efficient and stable blue emission of perovskite light-emitting diodes (PeLEDs) is a requisite toward their potential applications in full-color displays and solid-state lighting. Rational manipulation over the entire electroluminescence process is promising to break the efficiency limit of blue PeLEDs. Herein, a facile device architecture is proposed to achieve efficient blue PeLEDs for simultaneously reducing the energetic loss during electron-photon conversion and boosting the light outcoupling. Effective interfacial engineering is employed to manipulate the perovskite crystallization nucleation, enabling highly compact perovskite nanocrystal assemblies and suppressing the trap-induced carrier losses by means of interfacial hydrogen bonding interactions. This strategy contributes to a high external quantum efficiency (EQE) of 12.8% for blue PeLEDs emitting at 486 nm as well as improved operational stability. Moreover, blue PeLEDs reach a peak EQE of 16.8% with the incorporation of internal outcoupling structures for waveguided light, which can be further raised to 27.5% by integrating a lens-based structure for substrate-mode light. These results verify the validity of this strategy in producing efficient and stable blue PeLEDs for practical applications.
21 Jun 05:44
by Xiaohua Zhang, Pu Fan, Zijun Wang, Ding Zheng, and Junsheng Yu
![TOC Graphic]()
The Journal of Physical Chemistry C
DOI: 10.1021/acs.jpcc.1c03994
21 Jun 05:39
by Kenichi Ozawa, Susumu Yamamoto, Tetsuya Miyazawa, Keita Yano, Koji Okudaira, Kazuhiko Mase, and Iwao Matsuda
![TOC Graphic]()
The Journal of Physical Chemistry C
DOI: 10.1021/acs.jpcc.1c03584
19 Jun 12:38
by Hai Lin Wang,
Hui Feng Ma,
Mao Chen,
Shi Sun,
Tie Jun Cui
A reconfigurable multifunctional metasurface that demonstrates real-time control of transmission, absorption, and reflection of electromagnetic waves is proposed, and its performance is validated by both simulation and experiment. In addition, a potential application of the metasurface in a stealth radome is also proposed and demonstrated.
Abstract
Metasurfaces have attracted much attention in recent years due to their powerful abilities in manipulating electromagnetic (EM) waves. However, most of the previously reported metasurfaces are incapable of real-time control of full-space EM waves, including transmission, reflection, and absorption at the same time. In this paper, a reconfigurable multifunctional metasurface is proposed that demonstrates real-time control of transmission, absorption, and reflection of EM waves, which can be continuously controlled from total transmission to total reflection, and to perfect absorption. In the case of total reflection, the reflected waves can be further manipulated in a programmable way by changing the digital coding sequences via bias voltages. Meanwhile, the metasurface can independently control vertical and horizontal polarized waves in broadband. The reconfigurable functionalities of the metasurface are validated by experiments, which agree very well with numerical simulations. In addition, a potential application of the reconfigurable multifunctional metasurface in a stealth radome is proposed and demonstrated.
19 Jun 12:38
by Shucheng Qin,
Zhenrong Jia,
Lei Meng,
Can Zhu,
Wenbin Lai,
Jinyuan Zhang,
Wenchao Huang,
Chenkai Sun,
Beibei Qiu,
Yongfang Li
Two new small-molecule acceptors with different bandgaps are designed and synthesized for application in front and rear cells in tandem organic solar cells (OSCs) processed by non-halogenated solvents. When cooperating with appropriate polymer donors, the tandem OSCs processed by non-halogenated solvents demonstrate a power conversion efficiency of 16.67%.
Abstract
Organic solar cells (OSCs) have recently reached a remarkably high efficiency and become a promising technology for commercial application. However, OSCs with top efficiency are mostly processed by halogenated solvents and with additives that are not environmentally friendly, which hinders large-scale manufacture. In this study, high-performance tandem OSCs, based on polymer donors and two small-molecule acceptors with different bandgaps, are fabricated by solution processing with non-halogenated solvents without additive. Importantly, the two active layers developed from non-halogenated solvents show better phase segregation and charge transport properties, leading to superior performance than halogenated ones. As a result, a tandem OSC with high efficiency of up to 16.67% is obtained, showing unique advantages in future massive production.
19 Jun 12:36
by Min Soo Kim,
Woongsik Jang,
Thuc‐Quyen Nguyen,
Dong Hwan Wang
A mold-assisted decal-coating process is developed by controlling the surface energy of polymer molds by calculating for adhesion based on a wetting coefficient. The mold-assisted decal-coating contributes to higher performance of both photovoltaic device and photodetector than that of the spin-coated device. The decal-coated device reveals a favorable charge transfer property and suppressed morphological change over time due to morphology inversion and stabilization.
Abstract
In this study, a promising film formation technique is highlighted, named mold-assisted decal-coating, as a thin film transfer printing process using the polyurethane acrylate-based stamping mold. By optimizing the surface energy of the mold with wetting coefficient theory, the mold-assisted decal-coating process is successfully demonstrated by transferring the photoactive layer composed of the polymer donor, poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b′]dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)] and a narrow bandgap non-fullerene acceptor (NFA), 2,2′-[[4,4,9,9-tetrakis(4-hexylphenyl)-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl]bis[[4-[(2-ethylhexyl)oxy]-5,2-thiophenediyl]methylidyne(5,6-difluoro-3-oxo-1H-indene-2,1(3H)-diylidene)]]bis[propanedinitrile]. This process induces a well-ordered morphology of photoactive material, prevents damage to the underlying layer by suppressing the solvent penetration. Both photovoltaic cells and photodetectors prepared by the decal-coated photoactive layers containing fluorinated NFAs showed higher performance (power conversion efficiency = 10.69% and specific detectivity = 1.27 × 1012 A cm Hz1/2 W−1, respectively) than those of cells prepared by the spin-coating method owing to morphology inversion and smoother interface that led to suppressed internal resistance and enhanced charge flow in normal structure. Thus, the reproducible decal-coating process using a customized elastomeric mediator is an important thin film coating technique for efficient next-generation organic optoelectronic materials.
19 Jun 12:36
by Shuyan Liang,
Siying Li,
Yannan Zhang,
Tao Li,
Haoxiang Zhou,
Feng Jin,
Chuanxiang Sheng,
Gang Ni,
Jianyu Yuan,
Wanli Ma,
Haibin Zhao
In the PM6:Y6 blend, the strong intermolecular interaction and the formation of the delocalized excited state in acceptor Y6 are favorable for rapid exciton migration and hole transfer at donor/acceptor interfaces, thus resulting in a considerably high hole transfer efficiency of 71.4%. While the transfer efficiency only reaches 13.1% in PM6:3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone)-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]-dithiophene (ITIC) blend, due to the weak intermolecular π–π interaction in the ITIC component.
Abstract
Organic solar cells (OSCs) based on small molecular acceptors (SMAs) have made great development with a power conversion efficiency (PCE) over 16% due to the design of novel materials and advances in device preparation technology. This work fabricates two bulk-heterojunction photovoltaic devices containing the same wide-bandgap donor PM6, respectively, matched with popular Y6 and ITIC SMAs. The PM6:Y6-based device achieves a much higher PCE of 15.21% than the PM6:ITIC-based device of 9.02%. On the basis of comparisons of macroscopic performances in the quasistatic regime, transient absorption spectroscopy (TAS) is further performed to better understand the microscopic dynamics difference in charge separation processes between the two photovoltaic blends. According to the TAS results, the calculated hole transfer efficiency in PM6:Y6 is 71.4%, far greater than the efficiency of 13.1% in PM6:ITIC, demonstrating favorable charge separation at donor/acceptor interfaces via hole transfer channel in PM6:Y6. The favorable hole transfer in PM6:Y6 is accounted for by its better mutual miscibility between the donor and acceptor, and the formation of long-lived delocalized intramoiety excimer state in the acceptor. These results highlight the important role of proper molecular design strategy with strong intermolecular coupling and beneficial film morphology on facilitating charge generation in OSCs adopting SMAs.
18 Jun 03:44
by Anping Zeng,
Xiaoling Ma,
Mingao Pan,
Yuzhong Chen,
Ruijie Ma,
Heng Zhao,
Jianquan Zhang,
Ha Kyung Kim,
Ao Shang,
Siwei Luo,
Indunil Chathurangani Angunawela,
Yuan Chang,
Zhenyu Qi,
Huiliang Sun,
Joshua Yuk Lin Lai,
Harald Ade,
Wei Ma,
Fujun Zhang,
He Yan
In this study, a chlorinated polymer named D18-Cl is designed and synthesized, leading to highly efficient (near 18%) organic solar cells, yet whose performance is insensitive to its molecular weight. These advantages make D18-Cl a more promising donor polymer than previously reported polymer D18 for scale-up and low-cost production.
Abstract
In the field of non-fullerene organic solar cells (OSCs), compared to the rapid development of non-fullerene acceptors, the progress of high-performance donor polymers is relatively slow. The property and performance of donor polymers in OSCs are often sensitive to the molecular weight of the polymers. In this study, a chlorinated donor polymer named D18-Cl is reported, which can achieve high performance with a wide range of polymer molecular weight. The devices based on D18-Cl show a higher open-circuit voltage (V
OC) due to the slightly deeper energy levels and an outstanding short-circuit current density (J
SC) owing to the appropriate long periods of blend films and less ([6,6]-phenyl-C71-butyric acid methyl ester) (PC71BM) in mixed domains, leading to the higher efficiency of 17.97% than those of the D18-based devices (17.21%). Meanwhile, D18-Cl can achieve high efficiencies (17.30–17.97%) when its number-averaged molecular weight (M
n) is ranged from 45 to 72 kDa. In contrast, the D18-based devices only exhibit relatively high efficiencies in a narrow M
n range of ≈70 kDa. Such property and performance make D18-Cl a promising donor polymer for scale-up and low-cost production.
15 Jun 22:40
by Prashant Donthamsetti, David B. Konrad, Belinda Hetzler, Zhu Fu, Dirk Trauner, and Ehud Y. Isacoff
Journal of the American Chemical Society
DOI: 10.1021/jacs.1c02586
15 Jun 22:39
by Jianyu Zhang, Lianrui Hu, Kaihua Zhang, Junkai Liu, Xingguang Li, Haoran Wang, Zhaoyu Wang, Herman H. Y. Sung, Ian D. Williams, Zebing Zeng, Jacky W. Y. Lam, Haoke Zhang, and Ben Zhong Tang
Journal of the American Chemical Society
DOI: 10.1021/jacs.1c03882
15 Jun 22:39
by You-Quan Zou, Dawei Zhang, Tanya K. Ronson, Andrew Tarzia, Zifei Lu, Kim E. Jelfs, and Jonathan R. Nitschke
Journal of the American Chemical Society
DOI: 10.1021/jacs.1c05172
