TY - JOUR
T1 - Passivating Defects at the Bottom Interface of Perovskite by Ethylammonium to Improve the Performance of Perovskite Solar Cells
AU - Ren, Jiahao
AU - Liu, Tanghao
AU - He, Bingchen
AU - Wu, Guangbao
AU - Gu, Hao
AU - Wang, Bingzhe
AU - Li, Jielei
AU - Mao, Yulin
AU - Chen, Shi
AU - Xing, Guichuan
N1 - Publisher Copyright:
© 2022 Wiley-VCH GmbH.
Funding information:
J.R. and T.L. contributed equally to this work. The authors acknowledge the Science and Technology Development Fund, Macao SAR (File no. FDCT-0044/2020/A1, 0082/2021/A2), UM's research fund (File no. MYRG2020-00151-IAPME), the Natural Science Foundation of China (61935017, 62175268), Natural Science Foundation of Guangdong Province, China (2019A1515012186), Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials (2019B121205002), and Shenzhen-Hong Kong-Macao Science and Technology Innovation Project (Category C) (SGDX2020110309360100). T.L. acknowledges the start-up grant from the Department of Physics, Hong Kong Baptist University.
PY - 2022/11/24
Y1 - 2022/11/24
N2 - The interface of perovskite solar cells (PSCs) plays a significant role in influencing their performance, yet there is still scarce research focusing on their difficult-to-expose bottom interfaces. Herein, ethylammonium bromide (EABr) is introduced into the bottom interface and its passivation effects are studied directly. First, EABr can improve substrate wettability, which is beneficial for the perovskite-film deposition. By lifting off the perovskite film spontaneously from the substrate, it is found that EABr can significantly reduce the amount of unreacted PbI2 at the bottom interface. These PbI2 crystals have been recently identified as a major defect source and degradation site for perovskite film. Meanwhile, EABr also lifts the valence band maximum at the bottom side of perovskite from -5.38 to -5.09 eV, facilitating better hole transfer. Such a improvement is also verified by the study of charge carrier dynamics. Through introducing EABr, all photovoltaic parameters of the inverted PSCs are improved, and their power conversion efficiency (PCE) increases from 20.41% to 21.06%. The study highlights the importance of direct characterization of the bottom interface for a better passivation effect.
AB - The interface of perovskite solar cells (PSCs) plays a significant role in influencing their performance, yet there is still scarce research focusing on their difficult-to-expose bottom interfaces. Herein, ethylammonium bromide (EABr) is introduced into the bottom interface and its passivation effects are studied directly. First, EABr can improve substrate wettability, which is beneficial for the perovskite-film deposition. By lifting off the perovskite film spontaneously from the substrate, it is found that EABr can significantly reduce the amount of unreacted PbI2 at the bottom interface. These PbI2 crystals have been recently identified as a major defect source and degradation site for perovskite film. Meanwhile, EABr also lifts the valence band maximum at the bottom side of perovskite from -5.38 to -5.09 eV, facilitating better hole transfer. Such a improvement is also verified by the study of charge carrier dynamics. Through introducing EABr, all photovoltaic parameters of the inverted PSCs are improved, and their power conversion efficiency (PCE) increases from 20.41% to 21.06%. The study highlights the importance of direct characterization of the bottom interface for a better passivation effect.
KW - ammonium group
KW - bottom interface
KW - defect passivation
KW - energy-level alignment
KW - lead iodide residual
UR - https://www.webofscience.com/wos/woscc/full-record/WOS:000867353900001?SID=EUW1ED0A7AKVtBSy1rsE21S9XJ48D
UR - http://www.scopus.com/inward/record.url?scp=85139606884&partnerID=8YFLogxK
U2 - 10.1002/SMLL.202203536
DO - 10.1002/SMLL.202203536
M3 - Journal article
SN - 1613-6810
VL - 18
JO - Small
JF - Small
IS - 47
M1 - 2203536
ER -
