Potassium doping for grain boundary passivation and defect suppression enables highly-efficient kesterite solar cells  

作　　者：Yingfen Li Zhiqi Wang Yunhai Zhao Dajun Luo Xueliang Zhang Jun Zhao Zhenghua Su Shuo Chen Guangxing Liang 

机构地区：[1]College of Materials and Energy Engineering,Guizhou Institute of Technology,Guiyang 550003,China [2]Shenzhen Key Laboratory of Advanced Thin Films and Applications,Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province,College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,China

出　　处：《Chinese Chemical Letters》2024年第11期565-570,共6页中国化学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.62074102);Science and Technology Plan Project of Shenzhen(No.20220808165025003)China;Science and Technology Project of Guizhou Province(No.QKHJCZK[2023]YB130);The Growth Plan for Young Science and Technology Talents of Guizhou Education Department(No.QJH KY[2017]223)。

摘　　要：The complicated and diverse deep defects,voids,and grain boundary in the CZTSSe absorber are the main reasons for carrier recombination and efficiency degradation.The further improvement of the open-circuit voltage and fill factor so as to increase the efficiency of CZTSSe device is urgent.In this work,we obtained K-doped CZTSSe absorber by a simple solution method.The medium-sized K atoms,which combine the advantages of light and heavy alkali metals,are able to enter the grain interior as well as segregate at grain boundary.The K-Se liquid phase can improve the absorber crystallinity.We find that the accumulation of the wide bandgap compound K_(2)Sn_(2)S_(5)at grain boundary can increase the contact potential difference of grain boundary,form more effective hole barriers,and enhance the charge separation ability.At the same time,K doping passivates the interface as well as bulk defects and suppresses the non-radiative recombination.The improved crystallinity,enhanced charge transport capability and reduced defect density due to K doping result in a significant enhancement of the carrier lifetime,leading to 13.04%device efficiency.This study provides a new idea for simultaneous realization of grain boundary passivation and defect suppression in inorganic kesterite solar cells.

关 键 词：KESTERITE Solar cell Chemical doping DEFECT Efficiency 

分 类 号：TM914.4[电气工程—电力电子与电力传动]