Wang Xunchang, Huang Da, Han Jianhua, Hu Liwen, Xiao Cong, Li Zhiya, Yang Renqiang
Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education), School of Chemical and Environmental Engineering, Jianghan University, Wuhan 430056, China.
CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.
ACS Appl Mater Interfaces. 2021 Mar 10;13(9):11108-11116. doi: 10.1021/acsami.0c21986. Epub 2021 Feb 26.
In order to obtain high-performance all-small-molecule organic solar cells (ASM-OSCs), it is crucial to exploit the available strategy for molecular design and to further understand key structure-property relationship that can rationally control the blend nanomorphology and influence the physical process. In this work, we design two small molecule donors FBD-S1 and TBD-S2 with identical electron-withdrawing units but various asymmetric central cores, which exhibit differing phase separation in Y6-based blend films. It is found that TBD-S2 with increased phase separation between donor and acceptor can lead to more favorable interpenetrating networks, effective exciton dissociation, and enhanced and more balanced charge transport. Importantly, a remarkable PCE of 13.1% is obtained for TBD-S2:Y6 based ASM-OSCs, which is an attractive photovoltaic performance for ASM-OSCs. This result demonstrates that the central core modification at the atomic level for small molecule donors can delicately control the phase separation and optimize photophysical processes, and refines device performance, which facilitate development in the ASM-OSC research field.
为了获得高性能的全小分子有机太阳能电池（ASM-OSCs），利用现有的分子设计策略并进一步理解能够合理控制共混物纳米形貌并影响物理过程的关键结构-性能关系至关重要。在这项工作中，我们设计了两种具有相同吸电子单元但不同不对称中心核的小分子给体FBD-S1和TBD-S2，它们在基于Y6的共混膜中表现出不同的相分离。研究发现，供体和受体之间相分离增加的TBD-S2能够导致更有利的互穿网络、有效的激子解离以及增强且更平衡的电荷传输。重要的是，基于TBD-S2:Y6的ASM-OSCs获得了13.1%的显著功率转换效率（PCE），这对于ASM-OSCs来说是具有吸引力的光伏性能。该结果表明，对小分子给体进行原子水平的中心核修饰可以精细地控制相分离并优化光物理过程，从而改善器件性能，这有助于推动ASM-OSC研究领域的发展。
