~ 2019 ~

188. "Dopant‐Free Squaraine‐Based Polymeric Hole‐Transporting Materials with Comprehensive Passivation Effects for Efficient            All‐Inorganic Perovskite Solar Cells"

Xiao, Qi; Tian, Jingjing; Xue, Qifan; Wang, Jing; Xiong, Bijin; Han, Mengmeng; Li, Zhen; Zhu, Zonglong; Yip, Hin‐Lap;

Li, Zhong'an 

Angew.Chem.Int. Ed., 2019,58, 17724

Using N ,N ‐diarylanilinosquaraines as the comonomers gives polysquaraine hole‐transporting materials (HTMs) that have very high hole mobility. As a dopant‐free HTM for α‐CsPbI2Br‐based all‐inorganic perovskite solar cells, the power conversion efficiency (PCE) can reach 15.5 %, among the best for all‐inorganic PVSCs.

187. "Carbon–Oxygen‐Bridged Ladder‐Type Building Blocks for Highly Efficient Nonfullerene Acceptors"

Xiao, Zuo; Yang, Shangfeng; Yang, Zhou; Yang, Junliang; Yip, Hin‐Lap; Zhang, Fujun; He, Feng; Wang, Tao;

Wang, Jizheng; Yuan, Yongbo; Yang, Huai; Wang, Mingkui; Ding, Liming

Adv. Mater., 2019,31, 1804790

Thanks to the strong electron‐donating capability of carbon–oxygen‐bridged (CO‐bridged) ladder‐type building blocks, CO‐bridged nonfullerene acceptors (NFAs) present low bandgaps and strong light‐harvesting capability, delivering high short‐circuit current density (>28 mA cm−2) and high power conversion efficiency (>14% for single‐junction and >17% for tandem) in organic solar cells.

186. "A distorted lactam unit with intramolecular hydrogen bonds as the electron donor of polymer solar cells"

Wang, Hua-Chun; Ren, Minrun; Cao, Jian; Yin, Hong-Bo; Zhang, Guichuan; Xiao, Jingyang; Ren, Xiancheng; Yip, Hin-Lap; Xu, Yun-Xiang

J. Mater. Chem. C, 2019,7, 21190

184. "Backbone Fluorination of Polythiophenes Improves Device Performance of Non-Fullerene Polymer Solar Cells"

Jia, Xiao’e; Liu, Gongchu; Chen, Shanshan; Li, Zhenchao; Wang, Zhenfeng; Yin, Qingwu; Yip, Hin-Lap; Yang, Changduk; Duan, Chunhui; Huang, Fei; Cao, Yong

ACS Appl. Energy Mater., 2019,2, 7572

183. "Surpassing the 10% efficiency milestone for 1-cm 2 all-polymer solar cells"

Fan, Baobing; Zhong, Wenkai; Ying, Lei; Zhang, Difei; Li, Meijing; Lin, Yanrui; Xia, Ruoxi; Liu, Feng; Yip, Hin-Lap; Li, Ning; Ma, Yuguang; BrabecChristoph J., Huang, Fei; Cao, Yong 

Nat. Commun., 2019,10, 4100

182. "High-performance and stable CsPbBr 3 light-emitting diodes based on polymer additive treatment"

Cai, Wanqing; Chen, Ziming; Chen, Dongcheng; Su, Shijian; Xu, Qinghua; Yip, Hin-Lap; Cao, Yong

RSC Adv., 2019,9, 27684

181. "Multifunctional semitransparent organic solar cells with excellent infrared photon rejection"

Li, Xue; Xia, Ruoxi; Yan, Kangrong; Yip, Hin-Lap; Chen, Hongzheng; Li, Chang-Zhi

Chinese Chemical Letters, 2019, DOI: 10.1016/j.cclet.2019.08.046

180. "CsPb(IxBr1−x)3 solar cells"

Jia, Xue; Zuo, Chuantian; Tao, Shuxia; Sun, Kuan; Zhao, Yixin; Yang, Shangfeng; Cheng, Ming; Wang, Mingkui; Yuan, Yongbo; Yang, Junliang; Gao, Feng; Xing, Guichuan; Wei, Zhanhua; Zhang, Lijun; Yip, Hin-Lap; Liu, Mingzhen; Shen, Qing; Yin, Longwei; Han, Liyuan; Liu, Shengzhong; Wang, Lianzhou; Luo, Jingshan; Tan, Hairen; Jin, Zhiwen; Ding, Liming

Science Bulletin, 2019,64, 1532

We systematically review the progress of CsPb(IxBr1−x)3 solar cells in four aspects: phase stability, crystallization control, low-temperature preparation, and defect passivation. We propose challenges and future directions for developing highly efficient and stable devices.

179. "Engineering of perovskite light-emitting diodes based on quasi-2D perovskites formed by diamine cations"

Chen, Chiung-Han; Li, Zhenchao; Xue, Qifan; Su, Yu-An; Lee, Chia-Chen; Yip, Hin-Lap; Chen, Wen-Chang;

Chueh, Chu-Chen

Organic Electronics, 2019,75, 105400

A green light-emitting diode (LED) based on a quasi-2D EDBE(MAPbBr3)2PbBr4 film [EDBE: 2,2-(ethylenedioxy)bis(ethylammonium)] is fabricated and yield a maximum luminescence of 1903 cd m−2 with a maximum EQE of 1.06%, representing the first example of visible-light perovskite LED using Dion-Jacobson phase quasi-2D perovskite materials. Nevertheless, it is shown that the poor thermal stability of the EDBE-based 2D perovskite limits its resulting performance.

178. "The distinctive phase stability and defect physics in CsPbI2Br perovskite"

Chen, Yuxuan; Shi, Tingting; Liu, Pengyi; Xie, Weiguang; Chen, Ke; Xu, Xin; Shui, Lingling; Shang, Chaoqun;

Chen, Zhihong; Yip, Hin-Lap; Zhou, Guofu; Wang, Xin

J. Mater. Chem. A, 2019,7, 20201

The optoelectronic and defect properties of mixed-halide CsPbI2Br were explored, both α-phase and β-phase CsPbI2Br possess better thermal and phase stability than CsPbI3 due to the mixture of halide elements.

177. "Applications of organic additives in metal halide perovskite light-emitting diodes"

Li, Zhen-Chao; Chen, Zi-Ming; Zou, Guang-Rui-Xing; Yip, Hin-Lap; Cao, Yong

Acta Physica Sinica, 2019,68, 158505

近年来, 金属卤化钙钛矿凭借其优异的光电特性以及可低成本溶液加工的优势得到了学界的广泛关注, 成为了光电子领域的研究热点, 其中, 钙钛矿发光二极管是该领域的一大重要研究方向. 由于钙钛矿材料具有荧光量子效率高、带隙连续可调、发光半峰宽窄等优点, 钙钛矿发光二极管在短短5年时间内, 实现了外量子效率从不足1%到超过20%的重大突破, 成为了发展速度最快的发光技术. 在这5年的发展历程中, 学界主要集中于解决如何实现钙钛矿成膜和结晶过程的控制、如何提高钙钛矿薄膜的荧光量子效率, 以及如何改善钙钛矿发光二极管的稳定性等问题. 而在众多解决方案中, 有机添加剂的使用被认为是一种简单且有效的策略. 本文通过文献综述, 回顾了有机添加剂在钙钛矿发光二极管领域的整体发展和应用情况, 并着重讨论了小分子与聚合物添加剂在钙钛矿中的具体作用, 最后分析了当前钙钛矿发光二极管面临的问题, 并对其未来发展进行了展望.

176. "Highly transparent organic solar cells with all‐near‐infrared photoactive materials"

Xie, Yuanpeng; Xia, Ruoxi; Li, Tengfei; Ye, Linglong; Zhan, Xiaowei; Yip, Hin‐Lap; Sun, Yanming

Small Methods, 2019,3, 1900424

All‐near‐infrared transparent organic solar cells (T‐OSCs) are fabricated using a new method involving two ultranarrow bandgap (𝐸g(opt) < 1.4 eV) photoactive materials. The T‐OSC yields an outstanding visible light transmittance of 61.5% with an efficiency of 3.5%, indicating great potential of all‐NIR materials in high‐quality T‐OSCs.

175. "Achieving both enhanced voltage and current through fine‐tuning molecular backbone and morphology control in                    organic solar cells"

Gao, Huan‐Huan; Sun, Yanna; Cai, Yao; Wan, Xiangjian; Meng, Lingxian; Ke, Xin; Li, Shitong; Zhang, Yamin; Xia, Ruoxi; Zheng, Nan; Xie, Zengqi; Li, Chenxi; Zhang, Mingtao; Yip, Hin-Lap; Cao, Yong; Chen, Yongsheng

Adv. Energy Mater., 2019,9, 1901024

A simple yet effective side chain modulation on the backbone for obtaining both enhanced V ocand J sc simultaneously is demonstrated in this work. Compared with the controlled molecule 3TT‐CIC, 3TT‐OCIC showed PCE of 13.13% with improved V oc of 0.69 V and J sc of 27.58 mA cm−2, and the tandem device gives an excellent efficiency of 15.72%.

174. "The Energy‐Alignment Engineering in Polytriphenylamines‐Based Hole Transport Polymers Realizes Low Energy                Loss and High Efficiency for All‐Inorganic Perovskite Solar Cells"

Zhang, Bin; Zhou, Yingzhi; Xue, Qifan; Tian, Jingjing; Yao, Qin; Zang, Yue; Wang, Lei; Yang, Wei; Yip, Hin-Lap;

Cao, Yong

Solar RRL, 2019,2, 1900265

Three novel polytriphenylamine‐based polymers (H‐Z1, H‐Z2, and H‐Z3) are designed and applied as hole‐transport layers in all‐inorganic perovskite solar cells. Due to the gradual deepening of the highest occupied molecular orbital energy levels from H‐Z1, H‐Z2 to H‐Z3, the energy loss (E loss) can be decreased from 0.69, 0.64, to 0.62 eV for H‐Z1, H‐Z2, and H‐Z3, respectively.

173. "Reduced open-circuit voltage loss for highly efficient low-bandgap perovskite solar cells via suppression of silver diffusion"

Liu, Meiyue; Chen, Ziming; Yang, Yongchao; Yip, Hin-Lap; Cao, Yong

J. Mater. Chem. A, 2019,7, 17324

Ag diffused across the PCBM layer increased the trap density and down-shifted the energy level of the perovskite layer. Fortunately, PCBM/ZnO layer efficiently suppressed the Ag diffusion, resulting in a perovskite solar cell with PCE of 18.1%.

172. "Achieving efficient organic solar cells and broadband photodetectors via simple compositional tuning of ternary blends"

Liu, Zhi-Xi; Lau, Tsz-Ki; Zhou, Guanqing; Li, Shuixing; Ren, Jie; Das, Sandeep K; Xia, Ruoxi; Wu, Gang; Zhu, Haiming; Lu, Xinhui; Yip, Hin-Lap; Chen, Hongzheng; Li, Chang-Zhi

Nano Energy, 2019,63, 103807

New access of functional organic electronics potentially yields exceptional Nano-gadgets with wide impacts. We report herein the first construction of panchromatic organic solar cell (OSC) and photodetector (OPD) via simple compositional tuning of ternary blends, wherein the modulation of fullerene ratio in near infrared (NIR) ternary blend (from low to high) effectively switches device charge transduction from the smooth carrier transfer and transport for photocurrent gain in photovoltaics, to the trap-limited dark current suppression in photodetectors. As results, excellent power conversion efficiencies (PCEs) of 11.49% and 14.27% are achieved in single junction and tandem OSCs containing non-fullerene-dominated (NFD) ternary blends. More interestingly, further increase of fullerene content in ternary blend helps no photovoltaic performance gain, while effectively suppressing dark current of devices. Fullerene-dominated (FD) ternary blend facilitates self-powered OPD with excellent detectivity above 1014 Jones over broad spectra range. These results establish that the effective yet simple strategy to access high-performance panchromatic ternary OSCs and OPDs.

The efficiency and photostability of all‐inorganic mixed‐halide perovskite solar cells (PVSCs) can be simultaneously enhanced by introducing an amino‐functionalized polymer PN4N as a novel cathode interlayer and dopant‐free PDCBT hole‐transporting layer. The favorable interaction between perovskite crystal and PN4N/PDCBT can effectively improve CsPbI2Br film quality, with power conversion efficiency over 16%.

171. "Dual Interfacial Design for Efficient CsPbI2Br Perovskite Solar Cells with Improved Photostability"

Tian, Jingjing; Xue, Qifan; Tang, Xiaofeng; Chen, Yuxuan; Li, Ning; Hu, Zhicheng; Shi, Tingting; Wang, Xin; Huang, Fei; Brabec, Christoph J; Yip, Hin‐Lap; Cao, Yong

Adv. Mater., 2019,31, 191152

Here, we report that one of the causes for the performance discrepancy might be the large surface dipole on the s-NiOx surface. We find that the perovskite deposited on the as-prepared sol-gel derived s-NiOx has large number of defects at the s-NiOx/perovskite interface. Based on the in-depth mechanism study with various spectroscopy techniques, we propose that the strong surface dipole of the s-NiOx composite film induces adhesion of perovskite precursor ions on the surface of s-NiOx during the perovskite film formation and creates defects in the perovskite crystals at the interface. As a result, the PVSCs based on the n-Butylamine treated s-NiOx layer have achieved a dramatical enhancement in PCE to 18.9% with decent stability at the maximum power point tracking. It is believed that this work provides insight and strategy to develop highly reproducible PVSCs with solution derived metal oxide as interlayers.

170. "Impact of surface dipole in NiOx on the crystallization and photovoltaic performance of organometal halide perovskite solar            cells"

Cheng, Yuanhang; Li, Menglin; Liu, Xixia; Cheung, Sin Hang; Chandran, Hrisheekesh Thachoth; Li, Ho-Wa; Xu, Xiuwen; Xie, Yue-Min; So, Shu Kong; Yip, Hin-Lap; Tsang, Sai-Wing

Nano Energy, 2019,61, 496

A tandem organic solar cell is fabricated employing subcells with the same donor PBDB‐T and two acceptors F‐M and NNBDT with complementary absorptions. A power conversion efficiency of 14.52% is achieved with a high V oc of 1.82 V, a notable FF of 74.7%, and a decent J sc of 10.68 mA cm−2.

169. "A tandem organic solar cell with PCE of 14.52% employing subcells with the same polymer donor and two absorption                      complementary acceptors"

Meng, Lingxian; Yi, Yuan‐Qiu‐Qiang; Wan, Xiangjian; Zhang, Yamin; Ke, Xin; Kan, Bin; Wang, Yanbo; Xia, Ruoxi; Yip, Hin‐Lap; Li, Chenxi; Chen, Yongshen

Adv. Mater., 2019,31, 1804723

Employing an electron‐deficient‐core‐based fused structure instead of a fused donor unit represents a new strategy to adjust the optoelectronic properties of acceptor–donor–acceptor‐type n‐type organic semiconductors. The electron‐deficient‐core based on benzothiadiazole together with dicyanomethylene derivative realizes a low bandgap, high electron mobility, and suitable energy level simultaneously, affording universal and high performances when blending with different donor polymers.

168. "Fused Benzothiadiazole: A Building Block for n‐Type Organic Acceptor to Achieve High‐Performance Organic Solar          Cells"

Yuan, Jun; Zhang, Yunqiang; Zhou, Liuyang; Zhang, Chujun; Lau, Tsz‐Ki; Zhang, Guichuan; Lu, Xinhui; Yip, Hin‐Lap; So, Shu Kong; Beaupré, Serge; Mainville, Mathieu;  Johnson, Paul A.; Leclerc, Mario;  Chen, Honggang; Peng, Hongjian; Li, Yongfang;   Zou, Yingping

Adv. Mater., 2019,31, 1807577

A new class of non-fullerene acceptor, Y6, by employing a ladder-type electrondeficient-core-based central fused ring with a benzothiadiazole core is reported. Organic photovoltaics made from Y6 in conventional and inverted architectures each exhibited a high efficiency of 15.7%, measured in two separate labs. Inverted device structures certified at Enli Tech Laboratory demonstrated an efficiency of 14.9%. Y6-based devices maintained the efficiency of 13.6% with an active layer thickness of 300 nm

167. "Single-junction organic solar cell with over 15% efficiency using fused-ring acceptor with electron-deficient core"

Yuan, Jun; Zhang, Yunqiang; Zhou, Liuyang; Zhang, Guichuan; Yip, Hin-Lap; Lau, Tsz-Ki; Lu, Xinhui; Zhu, Can; Peng, Hongjian; Johnson, Paul A; Leclerc, Mario; Cao, Yong; Ulanski, Jacek; Li, Yongfang; Zou, Yingping

Joule, 2019,3, 1140

Replacing the acceptors of 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) and another fuse ring acceptor with withdrawing units of 1,1‐dicyanomethylene‐3‐indanone and hexyl side chains (IDIC) with rhodanine‐benzothiadiazole‐coupled indacenodithiophene with branched 2‐ethylhexyl side chains (EH‐IDT) in nonfullerene organic solar cells can not only enhance power conversion efficiency but also extend device longevity under light. Good miscibility between the donor and the acceptor is found to be a key factor in stabilizing the film morphology of the active layer and contributes to an excellent photostability.

166. "An operando study on the photostability of nonfullerene organic solar cells"

Xiao, Jingyang; Ren, Minrun; Zhang, Guichuan; Wang, Jianbin; Zhang, Donglian; Liu, Linlin; Li, Ning; Brabec, Christoph J; Yip, Hin-Lap; Cao, Yong

Solar RRL, 2019,3, 1900077

Halide perovskite based light-emitting diodes attracted intensive research interest recently but the efficiency of blue diodes is much lower than the green and red ones. Here Li et al. push up the efficiency of blue diodes through composition engineering and vertical morphology control. 

165. "Modulation of recombination zone position for quasi-two-dimensional blue perovskite light-emitting diodes with                    efficiency exceeding 5%"

Li, Zhenchao; Chen, Ziming; Yang, Yongchao; Xue, Qifan; Yip, Hin-Lap; Cao, Yong

Nat. Commun., 2019,10, 1047

164. "Structurally Reconstructed CsPbI2Br Perovskite for Highly Stable and Square‐Centimeter All‐Inorganic Perovskite             Solar Cells"

Liu, Chong; Li, Wenzhe; Li, Huanyong; Wang, Huamin; Zhang, Cuiling; Yang, Yingguo; Gao, Xingyu; Xue, Qifan; Yip, Hin‐Lap; Fan, Jiandong; Schropp, Ruud E. I.; Mai, Yaohua

Adv. Energy Mater., 2019,9, 1803572

Incorporation of indium(III) chloride is directly shown to induce the structural reconstruction of CsPbI2Br perovskite at the microscopic level, which allows the stabilization of the α‐phase perovskite by means of increasing the structure tolerance factor and decreasing the grain size. Consequently, the square‐centimeter all‐inorganic InCl3:CsPbI2Br perovskite solar cells yield a power conversion efficiency of 11.4% with high stability.

Spectral engineering and ternary blend approaches were employed to demonstrate an efficient semitransparent polymer solar cell tailored for greenhouse application. The semitransparent device transmits mainly blue and red lights for photosynthesis, and shows a high efficiency of 7.75% with a crop growth factor of 24.8%. Optimal sunlight harvesting in photovoltaics and photosynthesis will be beneficial for future greenhouse application.

163. "Spectral Engineering of Semitransparent Polymer Solar Cells for Greenhouse Applications"

Shi, Hui; Xia, Ruoxi; Zhang, Guichuan; Yip, Hin‐Lap; Cao, Yong

Adv. Energy Mater., 2019,9, 1803438

A cascade-type and energy-level-aligned electron transport layer of ZnO/SnO2/C60-SAM is beneficial for suppressed charge recombination and improved charge extraction in low-bandgap perovskite solar cells, resulting in a reduced Voc loss.

161. "Fluoro-and Amino-Functionalized Conjugated Polymers as Electron Transport Materials for Perovskite Solar Cells              with Improved Efficiency and Stability"

Li, Tian; Hu, Zhicheng; Liu, Xiaocheng; Liu, Zixian; Guo, Peipei; Xu, Baomin; Xue, Qifan; Yip, Hin-Lap; Huang, Fei; Cao, Yong; 

ACS Appl. Mater. Interfaces, 2019,11, 5289

We report here novel bifunctionalized electron transport materials (ETMs) that can improve the efficiency and stability of perovskite solar cells (PVSCs) simultaneously. By functionalizing n-type conjugated polymers with fluoro and amino side chains, PN, PN-F25%, and PN-F50% with varied contents of fluoro and amino side chains are prepared. It is found that the amino side chains in ETMs efficiently improve the interface contact and electron collection of PVSCs, with improved power conversion efficiency from 14.0% for PC61BM-based devices to more than 17% for PN- and PN-F25%-based devices. Moreover, the fluoro side chains endow these polymers with excellent hydrophobic properties, which largely enhance their water-resistance capabilities. ETMs with the increased content of fluoro side chains can substantially improve the water resistance of perovskite layers, with a significant improvement in the stability of PVSCs. Our results indicate that the fluoro- and amino-bifunctionalized strategy is a promising method to design ETMs for high-performance and stable PVSCs.

160. "High‐performance large‐area organic solar cells enabled by sequential bilayer processing via nonhalogenated                   solvents"

Dong, Sheng; Zhang, Kai; Xie, Boming; Xiao, Jingyang; Yip, Hin‐Lap; Yan, He; Huang, Fei; Cao, Yong

Adv. Energy Mater., 2019,9, 1802832

A high‐performance (12.9%) non‐fullerene organic solar cell processed using a sequential bilayer deposition method from non‐halogenated solvents is reported. Using this method, the organic solar cell can be scaled up to a larger area (1 cm2) while maintaining a high performance of 11.4% by doctor‐blade coating. This method offers a truly compatible processing technique for printing large area organic solar cell modules.

159. "Highly stable enhanced near-infrared amplified spontaneous emission in solution-processed perovskite films by                   employing polymer and gold nanorods"

Wu, Xiao; Jiang, Xiao-Fang; Hu, Xiaowen; Zhang, Ding-Feng; Li, Shuang; Yao, Xiang; Liu, Wangwang; Yip, Hin-Lap; Tang, Zhilie; Xu, Qing-Hua

Nanoscale, 2019,11,1959

158. "Enhancing the performance of inverted perovskite solar cells via grain boundary passivation with carbon quantum dots"

Ma, Yuhui; Zhang, Heyi; Zhang, Yewei; Hu, Ruiyuan; Jiang, Mao; Zhang, Rui; Lv, Hao; Tian, Jingjing; Chu, Liang; Zhang, Jian; Xue, Qifan; Yip, Hin-Lap; Xia, Ruidong; Li, Xing’ao; Huang, Wei

ACS Appl. Mater. Interfaces, 2019,11, 3044

157. "Incorporation of rubidium cations into blue perovskite quantum dot light-emitting diodes via FABr-modified multi-                cation hot-injection method"

Meng, Fanyuan; Liu, Xinyan; Cai, Xinyi; Gong, Zifeng; Li, Binbin; Xie, Wentao; Li, Mengke; Chen, Dongcheng; Yip, Hin-Lap; Su, Shi-Jian

Nanoscale, 2019,11,1295

156. "Optical Analysis for Semitransparent Organic Solar Cells"

Xia, Ruoxi; Gu, Honggang; Liu, Shiyuan; Zhang, Kai; Yip, Hin‐Lap; Cao, Yong

Solar RRL, 2019,3,1800270

155. "Efficient organic-inorganic hybrid cathode interfacial layer enabled by polymeric dopant and its application in large-            area polymer solar cells"

Dong, Sheng; Zhang, Kai; Liu, Xiang; Yin, Qingwu; Yip, Hin-Lap; Huang, Fei; Cao, Yong

Sci. China Chem., 2019,62,67

An organic-inorganic hybrid cathode interfacial layer (CIL) was developed by doping ZnO with the naphthalene-diimide based derivative NDI-PFNBr. It was found the resulting organic-inorganic hybrid CIL showed apparently improved conductivity and could act as an effective cathode interlayer to modify indium tin oxide (ITO) transparent electrodes. As a result, by employing the blend of PTB7-Th:PC71BM as the photoactive layer, the inverted polymer solar cells (PSCs) exhibited a remarkable enhancement of power conversion efficiency (PCE) from 8.52% for the control device to 10.04% for the device fabricated with the hybrid CIL. Moreover, all device parameters were simultaneously improved by using this hybrid CIL. The improved open-circuit voltage (VOC) was attributed to the reduced work function of the ITO cathode, whereas the enhancements in fill factor (FF) and short-circuit current density (JSC) were assigned to the increased conductivity and more effective charge extraction and collection at interface. Encouragingly, when the thickness of the hybrid CIL was increased to 80 nm, the resulting device could still keep a PCE of 8.81%, exhibiting less thickness dependence. Considering these advantages, 16 and 93 cm2 large-area PSCs modules were successfully fabricated from the hybrid CIL by using doctor-blade coating techniques and yielded a remarkable PCE of 8.05% and 4.49%, respectively. These results indicated that the hybrid CIL could be a promising candidate to serve as the cathode interlayer for high-performance large-area inverted PSCs.

154. "End-chain effects of non-fullerene acceptors on polymer solar cells"

Tang, Lu-Ming; Xiao, Jingyang; Bai, Wei-Yun; Li, Qing-Ya; Wang, Hua-Chun; Miao, Mao-Sheng; Yip, Hin-Lap; Xu, Yun-Xiang

Organic Electronics, 2019,64,1

Four acceptor1-acceptor2-donor-acceptor2-acceptor1 (A1-A2-D-A2-A1) structural electron acceptors with different end-chains were designed and synthesized which all possessed indacenodithiophene (IDT) core, benzothiadiazole (BT) bridge as acceptor2, and rhodanine (R) end groups as acceptor1. The non-fullerene acceptor attached with ethyl group is called IDT-BT-R2 and used as control compound. And the other three of them are attached with methoxymethyl, trifluoroethyl and 1-piperidino groups generating IDT-BT-RO, IDT-BT-RF3 and IDT-BT-RN, respectively. The influence of end-chains on their optoelectronic properties were compared between four non-fullerene acceptors. Compared with IDT-BT-R2, the molecule IDT-BT-RF3 show red-shifted light absorption and lower LUMO level because of the electron withdrawing property of fluorine atoms. OSCs based on IDT-BT-RF3 display more efficient charge separation and lower degree of monomolecular recombination, allowing OSCs to show higher short-circuit current (Jsc) than the system of IDT-BT-R2. OSCs based on IDT-BT-RO also show more efficient charge separation and less monomolecular recombination. Due to the elevated LUMO level of the acceptor IDT-BT-RN, organic solar cells (OSCs) utilizing this material as acceptor display high open-circuit voltage (Voc) of 1.10 eV and low energy loss of 0.49 eV when maintaining a relatively high power conversion efficiency (PCE) of 7.09%. We demonstrated that the end-chain engineering could finely tune the light absorption properties and energy levels of novel non-fullerene acceptors and eventually improved OSCs performance can be harvested.

@2020 by YIP RESEARCH GROUP  | South China University of Technology | Guangzhou, China