期刊
CHINESE CHEMICAL LETTERS
卷 35, 期 2, 页码 -出版社
ELSEVIER SCIENCE INC
DOI: 10.1016/j.cclet.2023.109018
关键词
Linked donor unit; Oligomeric donors; Crystallinity regulation; Organic solar cells
This study focuses on improving the performance of all-small-molecule organic solar cells (ASM-OSCs) by designing and synthesizing novel donors with suitable crystallinity. It was found that the introduction of chlorine atoms enhances the crystallinity of blend films but also leads to larger phase separation and more defects, resulting in lower power conversion efficiency. On the other hand, donors with appropriate crystallinity exhibited smaller domain size, more suitable crystallinity, and improved exciton dissociation efficiency, charge transport efficiency, and carrier mobility.
Improving the performance of all-small-molecule organic solar cells (ASM-OSCs) largely depends on the design and application of novel donors with appropriate crystallinity. Extending molecular conjugation is an effective method for regulating molecular stacking and crystallinity. In this work, we successfully designed and synthesized two novel acceptor-donor-donor-donor-acceptor (A-D-D-D-A) type oligomeric donors with three dithieno[2,3- d :2 ' ,3 ' - d ' ]benzo[1,2- b :4,5- b ']dithiophene (DTBDT) as the central unit, named as 3DTBDT-Cl and 3DTBDT, depending on with and without chlorine substitution on the thiophene side chains. We found that the introduction of chlorine atoms makes the blend films display stronger crystallinity but with large-scale phase separation morphology and more defects, which eventually leads to a power conversion efficiency (PCE) of only 10.83%, whereas the blend films based 3DTBDT with appropriate crystallinity achieved 13.74% PCE. Compared with 3DTBDT-Cl/L8-BO, the 3DTBDT/L8BO films exhibited a nanoscale bi-continuous interpenetrating network morphology with a smaller domain size and more suitable crystallinity, which guarantees the corresponding devices obtained more efficient exciton dissociation, efficient charge transport, reduced bimolecular recombination, and performed more balanced carrier mobility. These results demonstrated that regulating the crystallinity of oligomeric donors to obtain the desired phase separation morphology in the blend films could facilitate further improving the performance of ASM-OSCs. (c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据