30 Oct 06:54
by Kou Yoshida,
Cheng Chen,
Harald Haas,
Graham A. Turnbull,
Ifor D. W. Samuel
High-speed red, green, and blue organic light-emitting diodes (RGB-OLEDs) are integrated onto a single substrate and achieve a record data transmission rate for an OLED transmitter system of 3.2 Gbps by exploiting wavelength-division multiplexing. It is demonstrated that integrating RGB pixels is a useful way to increase the data transmission rate of OLED transmitters.
Abstract
Organic light-emitting diodes (OLEDs) have been developed for high-speed transmitters of visible-light communication (VLC) but so far the possibility of direct fabrication of multiple colors on a single substrate has not been exploited for multi-Gbps data transmission. Very fast red-, green-, and blue (RGB)-emitting OLEDs are developed on a single substrate to realize high data transmission speed by wavelength division multiplexing (WDM). −6 dB electrical bandwidth of over 100 MHz is achieved for all colors by selecting fluorescent materials with nanosecond emission lifetimes and little overlap between their emission spectra and incorporating them into OLEDs designed for high-speed operation. Optical microcavities in top-emitting OLED structures are used to minimize spectral overlap. A record data transmission rate for an OLED transmitter system of 3.2 Gbps is demonstrated, by transmitting data with the 3 colors simultaneously and separating each data by dichroic mirrors. The results show that WDM with integrated RGB pixels is a useful way to increase the data transmission rate of a VLC system based on OLED transmitters, which has the potential to enable multi-gigabit transmission by displays. The availability of high-speed multiple-color devices as developed here also expands applications of OLEDs for spectroscopy, sensing, and ranging.
30 Oct 06:48
by Huanhuan Gao, Baobing Fan, Liyang Yu, Yiwen Wang, Ruipeng Li, Wenlin Jiang, Tianqi Chen, Jie Zeng, Francis R. Lin, Bin Kan, Hongxiang Li, Lei Wang, and Alex K.-Y. Jen
ACS Energy Letters
DOI: 10.1021/acsenergylett.4c02429
30 Oct 06:46
by Chengxi Sun, Zhenli Guo, Ying Tang, Xinchi Lu, Qixin Lv, Ping Li, Chao Zheng, and Runfeng Chen
ACS Applied Materials & Interfaces
DOI: 10.1021/acsami.4c13377
30 Oct 06:39
by Huifen Liu,
Yu Zhang,
Zijian Huang,
Yuetong Wu,
Lan Wang,
Guilin Liu,
Yanrun Chen,
Kailin Li,
Wenhua Zhang,
Huanping Zhou
In this work, effective p-type doping strategies for the representative crystalline polymer P3HT are explored to achieve efficient and stable PSCs. According to the Hard–Soft-Acid–Base theory, the soft base P3HT is more likely to form a stable Lewis acid–base adduct with the reactive soft acid radical, resulting in a strong charge-transfer interaction, thereby improving the doping efficiency.
Abstract
Perovskite solar cells (PSCs) have significant potential for next-generation photovoltaic technology applications. However, the instability of hole transport layers (HTLs) becomes the major obstacle to long-term operational devices, which are affected by the intrinsic thermal instability and loose structure of hole transport materials, as well as the hygroscopicity and migration of dopants. Here, poly(3-hexylthiophene-2,5-diyl) (P3HT) is used as a model crystalline polymer to thoroughly investigate effective p-type doping strategies and the underlying mechanism. According to Hard–Soft-Acid–Base theory, the soft base P3HT is more likely to form a stable Lewis acid–base adduct with the reactive soft acid radical, resulting in a strong charge-transfer interaction, thereby enhancing conductivity and regulating the energy band of the HTL. Meanwhile, the radical cation salt can promote pre-nucleation to optimize the crystallization orientation of P3HT. The resulting PSCs exhibited the efficiency of 25.16%, which is the highest efficiency reported so far based on doped P3HT. In addition, the resulting devices demonstrated excellent stability, maintaining 96.5%, 96%, and 91% of their initial efficiency after aging under continuous illumination for 2028 h, at 85 °C for 1080 h, and at maximum power point (MPP) tracking under continuous 1 Sun illumination at 85 °C for 528 h, respectively.
30 Oct 06:38
by Samah Akel,
Yueming Wang,
Genghua Yan,
Uwe Rau,
Thomas Kirchartz
Poor transport within the transport layers in halide perovskites can result in collection losses with increasing absorber thickness, which is often observed in cases of low absorber mobilities. This suggests that different optimization strategies for a better charge collection may be required by enhancing the absorber mobility if it is low, while improving the transport-layer mobility is the preferred strategy when the absorber-layer mobility is sufficient.
Abstract
The collection of photogenerated charges in halide perovskite solar cells depends on the thickness of the absorber layer, with larger thicknesses leading to a reduced collection efficiency. This observation has traditionally been associated with insufficiently high electron and hole diffusion lengths in the absorber layers. However, it is shown that in the presence of low-mobility contact layers, charge collection can be thickness-dependent, even if the absorber layer has infinite mobility. Here, analytical equations are derived for the thickness dependence of charge collection losses in situations where recombination is bulk or interface-limited and show how to relate these equations to voltage-dependent photoluminescence data. The analytical equations are compared to experimental data and numerical simulations and it is observed that experimental data on triple-cation perovskite devices with different thicknesses approximately follows the case, where bulk recombination dominates.
30 Oct 06:38
by Nakul Jain,
Rokas Jasiūnas,
Xian'e Li,
Huotian Zhang,
Jiehao Fu,
Rui Zhang,
Li Gang,
Mats Fahlman,
Vidmantas Gulbinas,
Feng Gao
Charge separation mechanism in state-of-the-art system has been a part of intense debate. Here, it is presented that as, the system moves toward the low-offset regime the thermal contribution plays an important role to derive the charge separation. The rational guide is provided to achieve the maximum CSE and maximum V
OC simultaneously within the mid-offset regime.
Abstract
In recent years, organic solar cells (OSCs) have shown high power efficiencies approaching 20%. However, the fundamental mechanisms of charge separation in these highly efficient devices have been a subject of intensive debates. Here, the charge separation efficiency (CSE) is extensively investigated across a wide range of blend systems with different energetic offsets. The findings unveil the temperature-dependent nature of charge separation in low-offset systems, emphasizing its significant contribution to the overall CSE. An intriguing inverse correlation between CSE and charge separation activation energy in relation to the offset is also observed. These results shed new light on the factors underlying the high CSE observed in the state-of-the-art devices.
30 Oct 06:37
by Mingyu Ma,
Xianyuan Jiang,
Zihao Zang,
Xin Wen,
Wei Zhou,
Haobo Wu,
Si Peng,
Yunlong Liu,
Hansheng Li,
Danni Yu,
Hao Liang,
Hao Wang,
Wenjia Zhou,
Zhenhuang Su,
Fan Zheng,
Xingyu Gao,
Alexei V. Emeline,
Constantinos C. Stoumpos,
Zhijun Ning
The study explores the use of the reductive molecule NH5F2 with a bi-fluoride anion to improve tin perovskite solar cells. This molecule reduces coordination energy with Sn2+, preventing phase segregation and enhancing film growth, resulting in a highly oriented, low-defect perovskite film, leading to a solar cell efficiency of 15.04%, one of the highest reported.
Abstract
Phase segregation can bring low crystallinity and orientation, giving rise to poor carrier transport and high defect density, leading to poor device performance. In order to reduce oxidation and defect density and regulate film growth, lots of reductive additives such as SnF2 are explored as additives in tin perovskite film growth. Despite the oxidation is effectively reduced, it induces phase segregation. Herein, a reductive molecule NH5F2 with a bi-fluoride anion is explored to address this challenge for tin perovskite solar cells. This bi-fluoride anion reduces coordination energy with Sn2+ compared to SnF2, hence the byproduct of [F─H─F]− can be eliminated during the film annealing process, effectively preventing fluoride segregation. As a result, a highly oriented perovskite film with reduced oxidation is fabricated. The film shows reduced defect density and carrier recombination, leading to improved current density. Consequently, a tin-based perovskite solar cell with an efficiency of 15.04% is fabricated, ranking as one of the highest efficiencies reported up to now.
30 Oct 06:30
by Yaqi Bao,
Maoxin Li,
Hangfan Jin,
Xiaobo Wang,
Jie Zeng,
Yang Feng,
Wei Hui,
Dourong Wang,
Lei Gu,
Jie Zhang,
Yikun Hua,
Xiao Wang,
Baomin Xu,
Wei Chen,
Zhongbin Wu,
Peter Müller‐Buschbaum,
Lin Song
An orderly arranged perovskite heterodomain is developed as the active layer for self-powered photodetectors. The alternate MAPbI3-FAPbI3 array not only directs charge carrier transport along the film normal and limits in-plane charge carrier diffusion, but also improves light harvesting. The obtained photodetector achieves a specific detectivity exceeding 1 × 1014 Jones for weak light over the whole visible light spectrum without external bias.
Abstract
Perovskite planar heterojunction is reported to promote charge-carrier separation at the interface due to the introduced built-in potential, leading to improved charge-carrier harvesting. However, the possible diffusion of charge carriers along the film lateral will increase their travel distance to respective electrodes, resulting in increased recombination probabilities. Constructing independent transport channels for positive and negative charge carriers individually is an efficient way to optimize the transport in the perovskite layer and thereby to achieve enhanced device performance. Here, a solution-based strategy is proposed to fabricate lateral bulk heterojunction (BHJ) by arranging methylammonium-based and formamidinium-based perovskites alternately in an ordered array with controllable domains. The structure of perovskite heterodomain directs charge carrier transport along the film normal and limits in-plane charge carrier diffusion. Moreover, the ordered perovskite array is found to greatly increase light harvesting. Consequently, the self-powered photodetector based on the perovskite heterodomain with a thickness of only 250 nm achieves a specific detectivity exceeding 1 × 1014 Jones for weak light over the whole visible light spectrum. This work provides guidance toward the fabrication of perovskite lateral BHJ using solution processing, meeting the requirements not only for charge-carrier manipulation but also for light management.
30 Oct 06:10
by Stijn Lenaers,
Stijn Lammar,
Anurag Krishna,
Valerio Stacchini,
Tom Cardeynaels,
Huguette Penxten,
Christ Weijtens,
Michael Verhage,
Bart Ruttens,
Wouter Maes,
Jan D'Haen,
Artem Musiienko,
Tom Aernouts,
Laurence Lutsen,
Dirk Vanderzande,
Jef Poortmans,
Wouter Van Gompel
This study introduces three novel SAMs in perovskite solar cells, with a pyrene-based SAM (4PAPyr) showing optimal energy level alignment and outperforming the commercial 2PACz. 4PAPyr enhances device performance, improves surface coverage, and achieves 22.2% power conversion efficiency, highlighting the importance of diversifying SAMs to unlock further efficiency and scalability improvements in perovskite solar cells.
Abstract
Recently, the efficiency of p-i-n perovskite solar cells drastically increased, a pivotal factor being the incorporation of self-assembled monolayers (SAMs) as a hole-transporting layer (HTL). SAMs offer many advantages over conventional HTLs, including minimal material requirements, low cost, and facile processing. Current research is mainly focused on the development of carbazole-derived SAMs. However, the versatility of organic chemistry allows for the design of SAMs with alternative organic cores that may possess specific benefits. In this study, three novel SAMs are incorporated in p-i-n perovskite solar cells, each based on an aromatic core commonly used in organic semiconductors. The novel SAMs vary in their energy level alignment with the perovskite active layer. Optimal alignment is achieved with a pyrene-based SAM (4PAPyr), resulting in solar cells that outperform the commercially available 2PACz. Moreover, due to improved surface coverage, the use of 4PAPyr leads to a significantly higher number of working solar cell devices when compared to 2PACz, which is of particular interest with regard to upscaling. After device optimization, a power conversion efficiency of 22.2% is achieved with 4PAPyr. This research underlines the importance of diversifying SAMs to unlock further advancements in perovskite solar cell efficiency and scalability.
30 Oct 06:06
by Xin Wang,
Hui Wang,
Tong Shan,
Qingyi Ma,
Yanjie Chen,
Lifei Chen,
Xiaoming Zhao,
Feng Wang
A novel fluorocarbon-solvents bath annealing approach is developed, and the previously neglected solvent-to-solvent interaction between two fluorocarbon solvents, perfluorodecalin (PFD) and perfluorotoluene (PFT), and perovskite precursor solvents (e,g, dimethyl sulfoxide) is investigated to achieve highly crystalline and enlarged grain size of perovskite films. The resulting planar solar cell achieves a remarkable improved efficiency of 24.26% with suitability for large-area devices.
Abstract
Thermal annealing is a critical process in producing high-quality perovskite films for high-performance perovskite solar cells. Conventional TA presents challenges such as delayed heat transfer, leading to unwanted crystal growth and hindering processing scalability. Solvent-bath annealing is an attractive approach that can improve heat transfer and promote perovskite crystallization by immersing the as-deposited precursor film in a liquid medium. In this study, fluorocarbon-based solvents are developed as novel solvent baths for uniform heat flow through omnidirectional annealing. In addition, the previously neglected solvent-to-solvent interaction between fluorocarbon and solvents for perovskite precursor is investigated by comparing two fluorocarbon solvents. By increasing the solvent-solvent interaction, higher quality perovskite films with increased crystallinity, improved perovskite transition, and reduced film defects are achieved. As a result, the perovskite solar cells exhibited an increased power conversion efficiency with excellent reproducibility. These findings suggest that the selection of suitable solvent bath is promising for further improving perovskite quality and device performance.
30 Oct 05:55
by Yulong Wang,
Jiahui Chen,
Yuxi Zhang,
Pin Lv,
Junye Pan,
Min Hu,
Wen Liang Tan,
Zhiliang Ku,
Yi‐Bing Cheng,
Alexandr N. Simonov,
Jianfeng Lu
A vapor-to-solid deposition of high-quality large-area perovskite films is developed via a new process based on a 2D intermediated phase. Efficiencies of 21.1% and 20.1% are achieved for perovskite modules with active areas of 12.5 and 48.0 cm2, respectively.
Abstract
Perovskite solar cells (PSCs) can enable renewable electricity generation at low levelized costs, subject to the invention of an economically feasible technology for their large-scale fabrication, like vapor deposition. This approach is effective for the fabrication of small area (<1 cm2) PSCs, but its scale-up to produce high-efficiency larger area modules has been limited by a severe imbalance between the vapor-solid reaction kinetics and the mass-transport of the volatile ammonium salt precursor. In this study, an amidine-based low-dimensional perovskite is introduced as an intermediate of the solid-vapor reaction to help resolve this limitation. This improves reaction pathway produces unique vertically monolithic grains with no detectable horizontal boundaries, which is used to produce 1.0 cm2 PSCs with an efficiency of 22.1%, as well as 12.5 and 48 cm2 modules delivering 21.1% and 20.1% efficiency, respectively. The modules retain ≈85% of their initial performance after 900 h of continuous operation (ISOS-L-1 protocol) and ≈100% after 2800 h of storage in an ambient environment (ISOS-D-1 protocol).
30 Oct 05:54
by Chuanming Tian,
Tianhao Wu,
Xinliang Zhou,
Yu Zhao,
Bin Li,
Xuefei Han,
Kerui Li,
Chengyi Hou,
Yaogang Li,
Hongzhi Wang,
Qinghong Zhang
The two-step air-processed efficient PSCs with full lifecycle management are effectively realized by the polymer-stabilized precursor ink. The modified PSCs deliver an impressive efficiency of 25.18% with superior environmental and mechanical stability. The end-of-life PSCs with lead leakage suppression and device regeneration will not pose a threat to the environmental and biological safety.
Abstract
Despite the outstanding power conversion efficiency of perovskite solar cells (PSCs) realized over the years, the entire lifecycle from preparation and operation to discarding of PSCs still needs to be carefully considered when it faces the upcoming large-scale production and deployment. In this study, bio-derived chitin-based polymers are employed to realize the full lifecycle regulation of air-processed PSCs by forming multiple coordinated and hydrogen bonds to stabilize the lead iodide and organic salt precursor inks, accelerating the solid–liquid reaction and crystallization of two-step deposition process, then achieving the high crystalline and oriented perovskites with less notorious charge defects in the open air. The air-prepared PSCs exhibit a decent efficiency of 25.18% with high preparation reproducibility and improved operational stability toward the harsh environment and mechanical stress stimuli. The modified PSCs display negligible fatigue behavior with keeping 92% of its initial efficiency after operating for 32 diurnal cycles (ISOS-LC-1 protocol). Meanwhile, closed-loop lead management of end-of-life PSCs including suppression of lead leakage, toxicity evaluation of broken devices, and recycling of lead iodide components are comprehensively investigated. This work sheds light on a promising avenue to realize the entire lifecycle regulation of air-processed efficient and stable PSCs.
30 Oct 05:53
by Qiang Zhang,
Hao Huang,
Yingying Yang,
Min Wang,
Shujie Qu,
Zhineng Lan,
Tongtong Jiang,
Zhiwei Wang,
Shuxian Du,
Yi Lu,
Yi Suo,
Peng Cui,
Meicheng Li
A suitable solvent system of passivator can maximize the passivation effect, further improving the photovoltaic performance of perovskite solar cells (PSCs). This work proposes a ternary solvent system of 4-MeO-PEAI, which can inhibit the solvent-induced additional defects and achieve a sufficient passivated perovskite surface simultaneously. The resulting PSCs achieve an impressive power conversion efficiency (PCE) of 26.05%, and the devices can maintain 95.23% and 95.68% of their initial PCE after 2000 h storage in ambient air and 800 h light-soaking in N2-glovebox.
Abstract
Surface passivation is a vital approach to improve the photovoltaic performance of perovskite solar cells (PSCs), in which the passivator solvent is an inevitable but easy-ignored factor on passivation effects. Herein, a universal ternary solvent system of surface passivators is proposed through comprehensively considering the solubility and selective perovskite dissolution of the solvent to maximize the passivation effect. Tetrahydrothiophene 1-oxide (THTO) is selected as the passivation promoter by comparing the binding energy with perovskite and the ability to distort the perovskite lattice among various aprotic polar solvent molecules, which can facilitate the passivator's reaction with perovskite and achieve sufficient passivation on perovskite surface. Besides, chlorobenzene (CB) is used as the diluting agent to minimize the amount of isopropanol (IPA), inhibiting the additional solvent-induced defects. As a result, the planar PSCs achieve a power conversion efficiency (PCE) of 26.05%, (certificated 25.66%). Besides, the unencapsulated devices exhibit enhanced stability, which can maintain 95.23% and 95.68% of their initial PCE after 2000 h of storage in ambient air and 800 h of light-soaking in N2-glovebox. Moreover, this ternary solvent system also exhibits a well applicability and reliability in different passivator such as PEAI, BAI, and so on.
30 Oct 05:50
Chem. Commun., 2024, 60,13895-13898
DOI: 10.1039/D4CC05081A, Communication
Lili Ma, Yinliang Yang, Gulziba Anwar, Minqi Xie, Jie Yang, Jinwu Yan, Jingjing Wu, Chuanxiang Liu
A near-infrared fluorescent probe combining the thiolysis of dinitrophenyl (DNP) ether and DNP-marked electron-deficient quaternary carbon was developed for the first time.
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30 Oct 05:46
J. Mater. Chem. C, 2024, Advance Article
DOI: 10.1039/D4TC02821J, Paper
Cuifen Zhang, Zheng Li, Yi Lin, Zhibo Wang, Huawei Hu, Ming Wang, Zheng Tang, Zaifei Ma
ITO-free OSCs (PM6:Y6) blade-coated with o-xylene show enhanced donor–acceptor separation and trap density, leading to limited VOC. Acceptor side chain modification enhances the morphology and reduces traps, boosting photovoltaic performance.
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30 Oct 05:45
J. Mater. Chem. C, 2024, Advance Article
DOI: 10.1039/D4TC03014A, Paper
Open Access
Dallar Babaian, Daniel Hill, Ping Yu, Suchismita Guha
Transient absorption spectroscopy from chemical vapor deposited 2D perovskites shows differences in carrier dynamics depending on the organic cations. The decay reveals a strong contribution from the Auger recombination process at early times.
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25 Oct 02:22
by Lin Yang,
Ziyan Liu,
Tianfang Zheng,
Peng Li,
Jiangang Ma,
Xintong Zhang,
Hancheng Zhu,
Xiao‐Feng Wang,
Yichun Liu
The oxidation process of Nb2CT
x
MXene is methodically simulated at the atomic level and nanosecond timescales, predicting a transition from metal to semiconductor with 44% C atoms replaced by O atoms in Nb2CT
x
. By exploiting MXenes to their derivatives, a promising approach to designing ETL for photovoltaic technologies is demonstrated.
Abstract
In the realm of photovoltaic research, 2D transition metal carbides (MXenes) have gained significant interest due to their exceptional photoelectric capabilities. However, the instability of MXenes due to oxidation has a direct impact on their practical applications. In this work, the oxidation process of Nb2CT
x
MXene in aqueous systems is methodically simulated at the atomic level and nanosecond timescales, which elucidates the structural variations influenced by the synergistic effects of water and dissolved oxygen, predicting a transition from metal to semiconductor with 44% C atoms replaced by O atoms in Nb2CT
x
. Moreover, Nb2CT
x
with varying oxidation degrees is utilized as electron transport layers (ETLs) in perovskite solar cells (PSCs). Favorable energy level alignments with superior electron transfer capability are achieved by controlled oxidation. By further exploring the composites of Nb2CT
x
to its derivatives, the strong interaction of the nano-composites is demonstrated to be more effective for electron transport, thus the corresponding PSC achieves a better performance with long-term stability compared with the widely used ETLs like SnO2. This work unravels the oxidation dynamics of Nb2CT
x
and provides a promising approach to designing ETL by exploiting MXenes to their derivatives for photovoltaic technologies.
25 Oct 02:20
by Bin‐Wen Chen,
Kun Cao,
Xu Wang,
Zuo‐Chang Chen,
Sang Young Jeong,
Zhen‐Lin Qiu,
Le‐Shan Dai,
Yun‐Fei Li,
Ke‐Yue Yang,
Da‐Qin Yun,
Han Young Woo,
Lin‐Long Deng,
Su‐Yuan Xie,
Lan‐Sun Zheng
A novel D-π-A configured small-molecule donor DTICPF is developed, which exhibits strong and broad optical absorption, and deep highest occupied molecular orbital (HOMO) energy levels. Vacuum-deposited organic solar cells (OSCs) based on DTICPF: C70 display power conversion efficiency (PCE) of 9.36% (certified 9.15%) with short-circuit current density (J
sc) up to 17.49 mA cm−2, which is the highest J
sc reported so far for vacuum-deposited OSCs.
Abstract
The development of high-performance organic photovoltaic materials is of crucial importance for the commercialization of organic solar cells (OSCs). Herein, two structurally simple donor-π-conjugated linker-acceptor (D-π-A)-configured small-molecule donors with methyl-substituted triphenylamine as D unit, 1,1-dicyanomethylene-3-indanone as A unit, and thiophene or furan as π-conjugated linker, named DTICPT and DTICPF, are developed. DTICPT and DTICPF are facilely prepared via a two-step synthetic process with simple procedures. DTICPF with a furan π-conjugated linker exhibits stronger and broader optical absorption, deeper highest occupied molecular orbital (HOMO) energy levels, and better charge transport, compared to its thiophene analog DTICPT. As a result, vacuum-deposited OSCs based on DTICPF: C70 show an impressive power conversion efficiency (PCE) of 9.36% (certified 9.15%) with short-circuit current density (J
sc) up to 17.49 mA cm−2 (certified 17.56 mA cm−2), which is the highest J
sc reported so far for vacuum-deposited OSCs. Besides, devices based on DTICPT: C70 and DTICPF: C70 exhibit excellent long-term stability under different aging conditions. This work offers important insights into the rational design of D-π-A configured small-molecule donors for high efficient and stable vacuum-deposited OSCs.
25 Oct 02:19
by Zhichao Wang,
Zicheng Ding,
Nan Wu,
Lei Lang,
Shiqiang Wang,
Kui Zhao,
Shengzhong (Frank) Liu
The different groups of amidino additives can largely impact defect passivation and crystallization dynamics of FAPbI3 perovskite. Compared with ABAc containing carboxyl group, ABAm with amide group at para-position of amidino possesses large dipole and enables stronger interactions with perovskite components to produce high-quality perovskite film, delivering the higher efficiency of 24.60% and better long-term stability in ambient condition.
Abstract
Amidino-based additives show great potential in high-performance perovskite solar cells (PSCs). However, the role of different functional groups in amidino-based additives have not been well elucidated. Herein, two multifunctional amidino additives 4-amidinobenzoic acid hydrochloride (ABAc) and 4-amidinobenzamide hydrochloride (ABAm) are employed to improve the film quality of formamidinium lead iodide (FAPbI3) perovskites. Compared with ABAc, the amide group imparts ABAm with larger dipole moment and thus stronger interactions with the perovskite components, i.e., the hydrogen bonds between N…H and I− anion and coordination bonds between C = O and Pb2+ cation. It strengthens the passivation effect of iodine vacancy defect and slows down the crystallization process of α-FAPbI3, resulting in the significantly reduced non-radiative recombination, long carrier lifetime of 1.7 µs, uniformly large crystalline grains, and enhances hydrophobicity. Profiting from the improved film quality, the ABAm-treated PSC achieves a high efficiency of 24.60%, and maintains 93% of the initial efficiency after storage in ambient environment for 1200 hours. This work provides new insights for rational design of multifunctional additives regarding of defect passivation and crystallization control toward highly efficient and stable PSCs.
25 Oct 02:19
by Ziyu Chen,
Yonghao Su,
Qianxin Long,
Zhiyun Zhang,
Jianhua Su,
Lifang Guo
This work uses dihydrophenazine derivatives as dopants to build a series of co-doped epoxy resins. Under the UV excitation, dihydrophenazine derivatives generate radicals through an electron transfer process, which are stabilized by epoxy resin chains. The photothermal conversion efficiency of this process reaches 79.9%. This kind of material shows potential applications in transparent greenhouses and photovoltaic conversion.
Abstract
Organic radicals exhibit great potential in photothermal applications, however, their innate high reactivity with oxygen renders the preparation of stable organic radicals highly challenging. In this work, a series of co-doped radical polymers ares prepared by doping dihydrophenazine derivatives (DPPs) into the epoxy resin matrix. DPPs can form radical species through the electron transfer process, which are further stabilized by the complex 3D network structure of epoxy resin. Experimental results show that the photothermal conversion efficiency is as high as 79.9%, and the temperature can quickly rise to ≈130 °C within 60 s. Due to the excellent visible light transmittance and mechanical properties of co-doped systems, this study further demonstrates their practical applications in energy-saving solar windows and thermoelectric power generation.
25 Oct 02:15
by Yuhao Liu,
Lingling Zhan,
Zhongjie Li,
Hang Jiang,
Huayu Qiu,
Xiaokang Sun,
Hanlin Hu,
Rui Sun,
Jie Min,
Jinyang Yu,
Weifei Fu,
Shouchun Yin,
Hongzheng Chen
A molecular design strategy for the third component is proposed. Starting with the Y6 molecular framework, asymmetric non-fullerene acceptors (BTP-SA1, BTP-SA2, BTP-SA3) through end-group, side-chain, and halogenation modifications are created. The ternary device, D18/Y6:BTP-SA3, shows a synergistic improvement in V
OC, J
SC, and FF, resulting in a high PCE of 19.36%, showcasing tolerance to varying component ratios (10–50%).
Abstract
The ternary strategy proves effective for breakthroughs in organic photovoltaics (OPVs). Elevating three photovoltaic parameters synergistically, especially the proportion-insensitive third component, is crucial for efficient ternary devices. This work introduces a molecular design strategy by comprehensively analyzing asymmetric end groups, side-chain engineering, and halogenation to explore the outstanding optoelectronic properties of the proportion-insensitive third component in efficient ternary systems. Three asymmetric non-fullerene acceptors (BTP-SA1, BTP-SA2, and BTP-SA3) are synthesized based on the Y6 framework and incorporated as the third component into the D18:Y6 binary system. BTP-SA3, featuring asymmetric terminal (difluoro-indone and dichloride-cyanoindone terminal), with branched alkyl side chains, exhibited high open-circuit voltage (V
OC), balanced crystallinity and compatibility, achieving synergistic enhancements in V
OC (0.862 V), short circuit-current density (J
SC, 27.52 mA cm−2), fill fact (FF, 81.01%), and power convert efficiency (PCE, 19.19%). Device based on D18/Y6:BTP-SA3 (layer-by-layer processed) reached a high efficiency of 19.36%, demonstrating a high tolerance for BTP-SA3 (10–50%). This work provides novel insights into optimizing OPVs performances in multi-component systems and designing components with enhanced tolerance.
25 Oct 02:14
by Xiujie Zhao,
Yinyu Bao,
Zhengwu Pan,
Qianyu Su,
Darui Peng,
Deqing Gao,
Chengrong Yin,
Jianpu Wang,
Wei Huang
By adopting side-chain tailoring strategy, two polymer hole-transporting materials with high mobility and multisite passivation functions are developed for the buried-interface engineering of inverted quasi-2D Ruddlesden‒Popper perovskite solar cells (PSCs). Among which, PVCz-ThSMeTPA-based inverted quasi-2D PSCs achieve impressive power conversion efficiency of 22.37% along with excellent thermal and long-term stability.
Abstract
Although quasi-2D Ruddlesden‒Popper (RP) perovskite exhibits advantages in stability, their photovoltaic performance are still inferior to 3D counterparts. Optimizing the buried interface of RP perovskite and suppress energetic losses can be a promising approach for enhancing efficiency and stability of inverted quasi-2D RP perovskite solar cells (PSCs). Among which, constructing polymer hole-transporting materials (HTMs) with defect passivation functions is of great significance for buried-interface engineering of inverted quasi-2D RP PSCs. Herein, by employing side-chain tailoring strategy to extend the π-conjugation and regulate functionality of side-chain groups, target polymer HTMs (PVCz-ThSMeTPA and PVCz-ThOMeTPA) with high mobility and multisite passivation functions are achieved. The presence of more sulfur atom-containing groups in side-chain endows PVCz-ThSMeTPA with increased intra/intermolecular interaction, appropriate energy level, and enhanced buried interfacial interactions with quasi-2D RP perovskite. The hole mobility of PVCz-ThSMeTPA is up to 9.20 × 10−4 cm2 V−1 S−1. Furthermore, PVCz-ThSMeTPA as multifunctional polymer HTM with multiple chemical anchor sites for buried-interface engineering of quasi-2D PSCs can enable effective charge extraction, defects passivation, and perovskite crystallization modulation. Eventually, the PVCz-ThSMeTPA-based inverted quasi-2D PSC achieves a champion power conversion efficiency of 22.37%, which represents one of the highest power conversion efficiencies reported to date for quasi-2D RP PSCs.
25 Oct 02:12
by Yongbin Jin,
Huiping Feng,
Yingji Li,
Hong Zhang,
Xuelin Chen,
Yawen Zhong,
Qinghua Zeng,
Jiarong Huang,
Yalian Weng,
Jinxin Yang,
Chengbo Tian,
Jinyan Zhang,
Liqiang Xie,
Zhanhua Wei
Sodium periodate is employed to enhance the crystallinity and increase the Ni3+/Ni2+ ratio of sputtered NiO
x
thin films. This treatment improves SAM's anchoring capability on NiO
x
, optimizes hole extraction at the interface, and minimizes phase separation in perovskite films. As a result, the study successfully fabricates perovskite/silicon tandem solar cells with an impressive power conversion efficiency of up to 30.48%.
Abstract
Sputtering nickel oxide (NiO
x
) is a production-line-compatible route for depositing hole transport layers (HTL) in perovskite/silicon tandem solar cells. However, this technique often results in films with low crystallinity and structural flaws, which can impair electronic conductivity. Additionally, the complex surface chemistry and inadequate Ni3+/Ni2+ ratio impede the effective binding of self-assembled monolayers (SAMs), affecting hole extraction at the perovskite/HTL interface. Herein, these issues are addressed using a recrystallization strategy by treating sputtered NiO
x
thin films with sodium periodate (NaIO4), an industrially available oxidant. This treatment improved crystallinity and increased the Ni3+/Ni2+ ratio, resulting in a higher content of nickel oxyhydroxide. These enhancements strengthened the SAM's anchoring capability on NiO
x
and improved the hole extraction at the perovskite/HTL interface. Moreover, the NaIO4 treatment facilitated Na+ diffusion within the perovskite layer and minimized phase separation, thus improving device stability. As a result, single-junction perovskite solar cells with a 1.68 eV bandgap achieve a power conversion efficiency (PCE) of 23.22% for an area of 0.12 cm2. Perovskite/silicon tandem cells with an area of 1 cm2 reached a PCE of 30.48%. Encapsulated tandem devices retained 95% of their initial PCE after 300 h of maximum power point tracking under 1-sun illumination at 25 °C.
25 Oct 02:07
by Jingjuan Bai,
Lin Han,
Yiran Liu,
Lijuan Bu,
Shui Hu,
Jiaxin Ma,
Zewei Li,
Mingxing Chen,
Zhimin Ma,
Zhiyong Ma
A unique phenomenon of conformation-controlled expression of double phosphorescence components is discovered. N,N-di(naphthalen-2-yl)pyren-1-amine (NaPy) shows time-dependent and excitation-dependent after glow color change in copolymerized MMA film due to simultaneous expression of the double phosphorescence components. NaPy follows Kasha's rule in low-rigidity matrix but disobeys Kasha's rule in high-rigidity matrix. We believe that this work will promote application of intelligent organic phosphorescence materials.
Abstract
Double phosphorescence components from a single organic molecule is rarely reported before because most organic molecules must follow Kasha's rule and merely emit phosphorescence from T1 state. We discover a unique phenomenon of conformation-controlled expression of double phosphorescence components. The green phosphorescence component and the red phosphorescence component are assigned to the dinaphthylamine moiety and the pyrene unit of N,N-di(naphthalen-2-yl)pyren-1-amine (NaPy), respectively. NaPy shows time-dependent and excitation-dependent afterglow color change in copolymerized MMA film at room temperature due to simultaneous expression of the double phosphorescence components. However, in PMMA film and copolymerized MA film, NaPy just expresses the red phosphorescence component, suggesting that matrix rigidity greatly affects expression of the double phosphorescence components via altering conformation of NaPy. In low-rigidity matrix, the NaPy conformation is dyanmic due to free rotation and triplet excitons relax to T1 state via inner conversion or vibration relaxation, leading to the sole expression of the red phosphorescence component. In high-rigidity matrix, the highly twisted conformation of NaPy is stabilized due to limitation of rotation and triplet excitons at T1 state and T2 state return to S0 state separately, resulting in simultaneous expression of the double phosphorescence components. Thus, NaPy follows Kasha's rule in low-rigidity matrix but disobeys Kasha's rule in high-rigidity matrix. In high-rigidity matrix, the dinaphthylamine moiety and the pyrene unit can function relatively independently, resulting in time-dependent and excitation-dependent wide-range afterglow color change.
25 Oct 02:06
by Zambaga Otgonbayar,
Jiwon Kim,
Minki Sa,
Hwa Sung Lee,
Jungchul Noh,
Chang‐Min Yoon
Conventional black pigments composed of carbon black absorb both visible and near-infrared (NIR) light, hindering the detection capability of commercialized light detection and ranging (LiDAR) sensors. To overcome this limitation, various organic and inorganic LiDAR-detectable dark-tone materials are developed to effectively reflect specific wavelengths in NIR region, preparing for the future autonomous driving environment.
Abstract
Autonomous driving relies on the precise recognition of objects using light detection and ranging (LiDAR) technology, that operates at a specific wavelength of 905 nm. Black objects, such as carbon black used in vehicle coating, tend to absorb this specific wavelength significantly, which limits the performance of LiDAR sensors. To address this issue, researchers have explored creating dark-toned materials that can be detected by LiDAR with high NIR reflectivity while maintaining a true blackness (L* < 20 based on the CIE color coordinates). These materials fall into two categories: organic and inorganic pigments. Organic pigments can be synthetically adjusted to achieve true blackness by manipulating their functional groups, but achieving high NIR reflectivity remains challenging, often requiring a bilayer structure with NIR-reflective white base and an upper layer of organic black pigments. Additionally, the need for hydrophobic additives and resistance to degradation from sunlight further restricts their use. In the case of inorganic pigments, the desired LiDAR-detectable properties can be obtained through careful control of their composition, structure, and morphology, allowing for single-layer coatings with appropriate design. This review highlights recent advancements in developing organic and inorganic LiDAR-detectable black pigments and outlines future material design strategies for autonomous vehicle systems.
25 Oct 02:06
by Penghui Ren,
Guohui Luo,
Linfeng Zhang,
Xiuhong Geng,
Yi Zhang,
Xiongxiong Ling,
Junchang Zeng,
Xiaoping Wu,
Lingbo Xu,
Ping Lin,
Xuegong Yu,
Peng Wang,
Can Cui
A novel strategy of passivating 2D perovskite in 3D/2D heterojunction with a thin surface termination layer is proposed. It demonstrates that surface defects of 2D perovskite are terminated by the AMTD molecule through multi-site interaction, resulting in an impressive PCE of 25.09% and a high V
OC of 1.211 V processed in air, with significantly enhanced long-term illumination and storing stability.
Abstract
Bilayer 3D/2D heterojunction perovskite solar cells (PSCs) have attracted increasing interest due to great advantages of high power conversion efficiency (PCE) and ultrastability. Previous studies are mostly focused on addressing the issue of poor charge transport originated from the spacer cations or random phase distribution of 2D perovskite in 3D/2D heterojunction. However, the carrier recombination at the surface of 2D layer is often ignored. Herein, a novel strategy of passivating 2D perovskite in 3D/2D heterojunction with a thin surface termination layer (STL) is proposed. It demonstrates that surface defects of 2D perovskite are terminated by the molecule of 2-amino-5-mercapto-1,3,4-thiadiazole through multi-site interaction, leading to the significant suppression of non-radiative recombination and considerable improvement of hole transport with the well-aligned energy band simultaneously. As a result, the PSCs with the constructed 3D/2D/STL structure processed in air have achieved a champion PCE of 25.09% with high open-circuit voltage of 1.211 V (the voltage deficient of 0.349 V). The unencapsulated devices retain exceeding 90% of the initial PCE after storing in air for 1008 h or under illumination in N2 for 504 h. This work opens up an important, but unnoticed topic of defect passivation of 2D perovskite for 3D/2D heterojunction PSCs.
25 Oct 02:05
by Yi-Hen Mao, Miao-Ken Hung, Shang-Ting Chung, Sunil Sharma, Kuen-Wei Tsai, and Show-An Chen
ACS Applied Materials & Interfaces
DOI: 10.1021/acsami.4c15933
25 Oct 01:59
by Yunshu Meng, Wei Liu, Zhenjiang Liu, Mingxue Gao, Manman Fang, Jie Yang, Dongge Ma, and Zhen Li
ACS Applied Materials & Interfaces
DOI: 10.1021/acsami.4c13336
25 Oct 01:38
J. Mater. Chem. C, 2024, Advance Article
DOI: 10.1039/D4TC03925D, Paper
Vladyslav Ievtukhov, Michał Mońka, Olga Ciupak, Irena Bylińska, Piotr Bojarski, Karol Krzymiński, Illia E. Serdiuk
Superior triplet harvesting properties of TMCz-BO emitter are analyzed in liquid and solid media. The notions of dynamic and static excited-state mixing are introduced to explain dual and triple nature of S1 and T1 states as well as TADF mechanism.
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25 Oct 01:37
J. Mater. Chem. C, 2024, Advance Article
DOI: 10.1039/D4TC03450C, Paper
Open Access
Mateusz Urban, Karolina Wrochna, Paulina H. Marek-Urban, Dawid R. Natkowski, Krzysztof Woźniak, Piotr Pander, Andrew P. Monkman, Krzysztof Durka, Sergiusz Luliński
A series of spiro tetracoordinate organoboron chelate complexes showing strong and tuneable luminescence as well as TADF character were synthesised and comprehensively characterized.
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