Controllable Exciton Diffusion Length and Ultrafast Charge Generation in Ternary Organic Solar Cells  

作　　者：Sixuan Cheng Jiawei Qiao Peng Lu Wei Qin Xiaotao Hao 

机构地区：[1]School of Physics,State Key Laboratory of Crystal Materials,Shandong University,Jinan,Shandong,250100 China [2]School of Physics,National Demonstration Center for Experimental Physics Education,Shandong University,Jinan,Shandong,250100 China [3]ARC Centre of Excellence in Exciton Science,School of Chemistry,The University of Melbourne,Parkville,Victoria,3010 Australia

出　　处：《Chinese Journal of Chemistry》2024年第11期1275-1283,共9页中国化学（英文版）

基　　金：supported by the National Natural Science Foundation of China(52073162);Major Program of Natural Science Foundation of Shandong Province(ZR2019ZD43);X.T.H also acknowledges support from the Taishan Scholars Program(tstp20230610);ARC Centre of Excellence in Exciton Science(CE170100026).

摘　　要：Charge generation,a critical process in the operation of organic solar cell(OSC),requires thorough investigation in an ultrafast perspective.This work demonstrates that the utilization of alloy model for the non-fullerene acceptor(NFA)component can regulate the crystallization properties of active layer films,which in turn affects exciton diffusion and hole transfer(HT),ultimately influencing the charge generation process.By incorporating BTP-eC7 as a third component,without expanding absorption range or changing molecular energy levels but regulating the ultrafast exciton diffusion and HT processes,the power conversion efficiency(PCE)of the optimized PM6:BTP-eC9:BTP-eC7 based ternary OSC is improved from 17.30%to 17.83%,primarily due to the enhancement of short-circuit current density(JSC).Additionally,the introduction of BTP-eC7 also reduces the trap state density in the photoactive layer which helps to reduce the loss of JSC.This study introduces a novel approach for employing ternary alloy models by incorporating dual acceptors with similar structures,and elucidates the underlying mechanism of charge generation and JSC in ternary OSCs.

关 键 词：Organic photovoltaics Ternary strategy Exciton diffusion Hole transfer Trap state Kinetics Alloys PHOTOPHYSICS 

分 类 号：TM914.4[电气工程—电力电子与电力传动]