Enhanced charge separation by interchain hole delocalization in nonfullerene acceptor-based bulk heterojunction materials  

作　　者：Chang-Mok Oh Sujung Park Jihoon Lee Sung Heum Park Shinuk Cho In-Wook Hwang 

机构地区：[1]Advanced Photonics Research Institute,Gwangju Institute of Science and Technology,Gwangju,Republic of Korea [2]Department of Physics and Energy Harvest Storage Research Center,University of Ulsan,Ulsan,Republic of Korea [3]Department of Physics,Pukyong National University,Busan,Republic of Korea

出　　处：《Carbon Energy》2023年第7期27-37,共11页碳能源（英文）

基　　金：supported by the National Research Foundation of Korea(NRF)grants funded by the Korea government(MSIT)(2022R1F1A1065586,2019R1A6A1A11053838);the GIST Research Institute(GRI)APRI grant funded by the GIST in 2022.

摘　　要：Bulk heterojunction(BHJ)composites show improved power conversion efficiencies when optimized in terms of morphology using various film processing methods.A reduced carrier recombination loss in an optimized BHJ was characterized previously.However,the driving force that leads to this reduction was not clearly understood.In this study,we focus on the decreased carrier recombination loss and its driving force in optimized nonfullerene acceptor-based PTB7-Th:IEICO-4F BHJ composites.We demonstrate that the optimized BHJ shows deactivation in the sub-nanosecond nongeminate carrier recombination process.The driving force for this deactivation was determined to be the improved interchain hole delocalization between the polymers.An enhanced interchain hole delocalization was observed using steady-state photoinduced absorption(PIA)spectroscopy.In particular,increased splitting between the polaron PIA bands was noted.Moreover,improved interchain hole delocalization was observed for other state-of-the-art BHJ materials,including D18:Y6 with optimized morphologies.

关 键 词：bulk heterojunction interchain hole delocalization nonfullerene acceptor photoinduced absorption spectroscopy solar cell 

分 类 号：TM914.4[电气工程—电力电子与电力传动]