Seminar

Date 2021-11-16 
Time 16:00 
Title Pseudo-halide Anion Engineering for α-FAPbI3 perovskite solar cells 

■ 제 목:  Pseudo-halide Anion Engineering for α-FAPbI3 perovskite solar cells

 

 연 사:  김진영 교수 (UNIST)            

 

■ 일 시:  2021년 11월 16(화) 오후 4시 

 

■ Host :  신병하 교수 

 

■ 참가자 접속정보 (3:50분까지 참가를 부탁드립니다)   

      접속 링크: https://kaist.zoom.us/j/8080757553 

      ID: 808 075 7553

      비밀번호: 2021mse

 

 Abstract :  

Metal halide perovskites of the general formular ABX3 where A is a monovalent cation such as caesium, methylammonium or formamidinium, B stands for divalent lead, tin or germanium and X is a halide anion, have shown great potential as light harvesters for thin film photovoltaics. Amongst a large number of compositions investigated, the cubic a-phase of formamidinium lead triiodide (FAPbI3) has emerged as the most promising semiconductor for highly-efficient and stable perovskite solar cells (PSCs). Maximizing the performance of α-FAPbI3 has therefore become of vital importance for the perovskite research community. Here, we introduce a new anion engineering concept that employs the pseudo-halide formate (HCOO⁻) to supress anion vacancy electric defects present at grain-boundaries and the surface of the perovskite films and to augment their crystallinity, enabling PSCs to attain a record power conversion efficiency of 25.6 % (certified 25.2%), long-term operational stability and intense electroluminescence with external quantum efficiencies over 10%. Our findings open up a direct route to eliminate the most abundant and deleterious lattice defects present in metal halide perovskites providing a facile access to solution processable films with unprecedented opto-electronic performance.