Alleviating Interfacial Recombination of Heterojunction Electron Transport Layer via Oxygen Vacancy Engineering for Efficient Perovskite Solar Cells Over 23%  

作　　者：Yohan Ko Taemin Kim Chanyong Lee Changhyun Lee Yong Ju Yun Yongseok Jun 

机构地区：[1]Graduate School of Energy and Environment(KU-KIST Green School),Korea University,Seoul 02841,Korea

出　　处：《Energy & Environmental Materials》2023年第2期311-322,共12页能源与环境材料（英文）

基　　金：supported by the New&Renewable Energy Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)granted financial resource from the Ministry of Trade,Industry&Energy(MOTIE),Republic of Korea(No.20213091010020);National Research Foundation of Korea(NRF)grant funded by the Korea Government(MSIT)(2020R1A2C1101085);the Korea Institute of Planning and Evaluation for Technology in Food,Agriculture and Forestry(IPET)and Korea Smart Farm R&D Foundation(KosFarm)through Smart Farm Innovation Technology Development Program;funded by the Ministry of Agriculture,Food and Rural Affairs(MAFRA);the Ministry of Science and ICT(MSIT),Rural Development Administration(RDA)(421036-03).

摘　　要：Electron transport layer(ETL)is pivotal to charge carrier transport for PSCs to reach the Shockley-Queisser limit.This study provides a fundamental understanding of heterojunction electron transport layers(ETLs)at the atomic level for stable and efficient perovskite solar cells(PSCs).The bilayer structure of an ETL composed of SnO_(2) on TiO_(2) was examined,revealing a critical factor limiting its potential to obtain efficient performance.Alteration of oxygen vacancies in the TiO_(2) underlayer via an annealing process is found to induce manipulated band offsets at the interface between the TiO_(2) and SnO_(2) layers.In-depth electronic investigations of the bilayer structure elucidate the importance of the electronic properties at the interface between the TiO_(2) and SnO_(2) layers.The apparent correlation in hysteresis phenomena,including current density-voltage(J-V)curves,appears as a function of the type of band alignment.Density functional theory calculations reveal the intimate relationship between oxygen vacancies,deep trap states,and charge transport efficiency at the interface between the TiO_(2) and SnO_(2) layers.The formation of cascade band alignment via control over the TiO_(2) underlayer enhances device performance and suppresses hysteresis.Optimal performance exhibits a power conversion efficiency(PCE)of 23.45%with an open-circuit voltage(V_(oc))of 1.184 V,showing better device stability under maximum power point tracking compared with a staggered bilayer under one-sun continuous illumination.

关 键 词：electron transport bilayer heterojunction bilayers interfacial defect oxygen vacancy engineering perovskite solar cells 

分 类 号：TM914.4[电气工程—电力电子与电力传动]