A nonfullerene acceptor with pi-conjugation extended end groups to achieve enhanced photovoltaic performance
作者:
Liu, CY (Liu, Chunyan) [1] ; Wu, ZH (Wu, Zhihui) [1] ; Qiu, NL (Qiu, Nailiang) [2] ; Li, CX (Li, Chenxi) [3] , [4] ; Lu, Y (Lu, Yan) [1]
DOI
10.1039/d3nj00283g
在线发表
FEB 2023
已索引
2023-03-18
文献类型
Article; Early Access
摘要
An acceptor-donor-acceptor (A-D-A) type nonfullerene acceptor (NFA), namely TTNC, was designed and synthesized using a pi-conjugation extension strategy on the terminal unit based on one successful NFA material TTIC. Benefiting from the end-extended conjugation, the new molecule shows red-shifted absorption, more ordered packing, and maintained energy levels compared with TTIC. These advantages contribute to achieving favorable phase separation morphology and strong light-harvesting ability for the donor/acceptor blend film. By combining with a wide band-gap polymer donor PBDB-T, the optimized TTNC based devices exhibit a high power conversion efficiency (PCE) of 11.34%, mainly originating from an enhanced short-current density (J(sc)) of 20.95 mA cm(-2), especially an excellent fill factor (FF) of 71% which is obviously superior to that of TTIC (66%). The findings indicate that pi-conjugation extension is an effective way to manipulate the absorption range, molecular packing and charge mobility of NFAs for an outstanding photovoltaic performance, which offers valuable insight for designing high-efficiency organic solar cells.