Quasi-Homojunction Organic Nonfullerene Photovoltaics Featuring Fundamentals Distinct from Bulk Heterojunctions

Détails bibliographiques
Publié dans:	Advanced materials (Deerfield Beach, Fla.). - 1998. - 34(2022), 50 vom: 25. Dez., Seite e2206717
Auteur principal:	Wang, Yifan (Auteur)
Autres auteurs:	Price, Michael B, Bobba, Raja Sekhar, Lu, Heng, Xue, Jingwei, Wang, Yilin, Li, Mengyang, Ilina, Aleksandra, Hume, Paul A, Jia, Boyu, Li, Tengfei, Zhang, Yuchen, Davis, Nathaniel J L K, Tang, Zheng, Ma, Wei, Qiao, Quinn, Hodgkiss, Justin M, Zhan, Xiaowei
Format:	Article en ligne
Langue:	English
Publié:	2022
Accès à la collection:	Advanced materials (Deerfield Beach, Fla.)
Sujets:	Journal Article fused-ring electron acceptor nonfullerene organic solar cell quasi-homojunction

Description
Résumé:	© 2022 Wiley-VCH GmbH. In contrast to classical bulk heterojunction (BHJ) in organic solar cells (OSCs), the quasi-homojunction (QHJ) with extremely low donor content (≤10 wt.%) is unusual and generally yields much lower device efficiency. Here, representative polymer donors and nonfullerene acceptors are selected to fabricate QHJ OSCs, and a complete picture for the operation mechanisms of high-efficiency QHJ devices is illustrated. PTB7-Th:Y6 QHJ devices at donor:acceptor (D:A) ratios of 1:8 or 1:20 can achieve 95% or 64% of the efficiency obtained from its BHJ counterpart at the optimal D:A ratio of 1:1.2, respectively, whereas QHJ devices with other donors or acceptors suffer from rapid roll-off of efficiency when the donors are diluted. Through device physics and photophysics analyses, it is observed that a large portion of free charges can be intrinsically generated in the neat Y6 domains rather than at the D/A interface. Y6 also serves as an ambipolar transport channel, so that hole transport as also mainly through Y6 phase. The key role of PTB7-Th is primarily to reduce charge recombination, likely assisted by enhancing quadrupolar fields within Y6 itself, rather than the previously thought principal roles of light absorption, exciton splitting, and hole transport
Description:	Date Completed 19.12.2022 Date Revised 22.12.2022 published: Print-Electronic Citation Status PubMed-not-MEDLINE
ISSN:	1521-4095
DOI:	10.1002/adma.202206717