Utilizing 3,4-ethylenedioxythiophene(EDOT)-bridged non-fullerene acceptors for efficient organic solar cells  

作　　者：Sung Jae Jeon Young Hoon Kim Ie Na Kim Nam Gyu Yang Ji Hee Yun Doo Kyung Moon 

机构地区：[1]Nano and Information Materials(NIMs)Laboratory,Department of Chemical Engineering,Konkuk University,120 Neungdong-ro Gwangjin-gu,Seoul 05029,South Korea [2]Department of Academy of Applied Science and Technology,Konkuk University,120 Neungdong-ro Gwangjin-gu,Seoul 05029,South Korea

出　　处：《Journal of Energy Chemistry》2022年第2期194-204,共11页能源化学（英文版）

基　　金：supported by the KU Research Professor Program of Konkuk University;the Korea Institute of Energy Technology Evaluation and Planning (KETEP);the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (No. 20193091010110);a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. 2020R1A2C201091611)。

摘　　要：A rational design of efficient low-band-gap non-fullerene acceptors(NFAs)for high-performance organic solar cells(OSCs)remains challenging;the main constraint being the decrease in the energy level of the lowest unoccupied molecular orbitals(LUMOs)as the bandgap of A-D-A-type NFAs decrease.Therefore,the short current density(J_(sc))and open-circuit voltage(V_(oc))result in a trade-off relationship,making it difficult to obtain efficient OSCs.Herein,three NFAs(IFL-ED-4 F,IDT-ED-4 F,and IDTT-ED-2 F)were synthesized to address the above-mentioned issue by introducing 3,4-ethylenedioxythiophene(EDOT)as aπ-bridge.These NFAs exhibit relatively low bandgaps(1.67,1.42,and 1.49 eV,respectively)and upshifted LUMO levels(-3.88,-3.84,and-3.81 eV,respectively)compared with most reported low-band-gap NFAs.Consequently,the photovoltaic devices based on IDT-ED-4 F blended with a PBDB-T donor polymer showed the best power conversion efficiency(PCE)of 10.4%with a high J_(sc) of 22.1 mA cm^(-2) and Voc of 0.884 V among the examined NFAs.In contrast,IDTT-ED-4 F,which was designed with an asymmetric structure of the D-p-A type,showed the lowest efficiency of 1.5%owing to the poor morphology and charge transport properties of the binary blend.However,when this was introduced as the third component of the PM6:BTP-BO-4 Cl,complementary absorption and cascade energy-level alignment between the two substances could be achieved.Surprisingly,the IDTT-ED-4 F-based ternary blend device not only improved the Jscand Voc,but also achieved a PCE of 15.2%,which is approximately 5.3%higher than that of the reference device with a minimized energy loss of 0.488 eV.In addition,the universality of IDTT-ED-2 F as a third component was effectively demonstrated in other photoactive systems,specifically,PM6:BTPe C9 and PTB7-Th:IEICO-4 F.This work facilitates a better understanding of the structure–property relationship for utilizing efficient EDOT-bridged NFAs in high-performance OSC applications.

关 键 词：Non-fullerene acceptor 3 4-ethylenedioxythiophene Organic solar cell π-bridge π-spacer 

分 类 号：TB34[一般工业技术—材料科学与工程] TM914.4[电气工程—电力电子与电力传动]