TY - JOUR
T1 - Atomic structure and electrical/ionic activity of antiphase boundary in CH3NH3PbI3
AU - Chen, Shulin
AU - Wu, Changwei
AU - Shang, Qiuyu
AU - Liu, Zhetong
AU - He, Caili
AU - Zhou, Wenke
AU - Zhao, Jinjin
AU - Zhang, Jingmin
AU - Qi, Junlei
AU - Zhang, Qing
AU - Wang, Xiao
AU - Li, Jiangyu
AU - Gao, Peng
N1 - KAUST Repository Item: Exported on 2022-05-23
Acknowledgements: This research was financially supported by the National Natural Science Foundation of China (52125307, 11974023, 52021006, 11772207, 22003074, 52072006), Youth Innovation Promotion Association CAS, the Key R&D Program of Guangdong Province (2018B030327001, 2018B010109009), the Guangdong Provincial Key Laboratory Program from the Department of Science and Technology of Guangdong Province (2021B1212040001), Guangdong Basic and Applied Basic Research Foundation (2020A1515110580), International Cooperation Project of Guangdong Province (No. 2019A050510049), Guangdong Basic and Applied Basic Research Foundation (2022A1515012463), SIAT Innovation Program for Excellent Young Researchers (2022**), Natural Science Foundation of Hebei Province for distinguished young scholar (A2019210204) and China Postdoctoral Science Foundation (2021M703391). The authors gratefully acknowledge the Electron Microscopy Laboratory at Peking University for the use of electron microscopes and the support of the Center for Computational Science and Engineering at Southern University of Science and Technology. P. Gao, J.Y. Li, and S.L. Chen conceived and supervised the project. S.L. Chen carried out TEM experiments and analysed experimental data with the direction of P. Gao and help from J.M. Zhang. C.W. Wu performed the calculations under the guidance of X. Wang. Q.Y. Shang synthesized MAPbI thin films under the direction of Q. Zhang. Z.T. Liu carried out the EELS measurements. C.L. He prepared the CsPbBr materials under the guidance of J.J. Zhao. W.K. Zhou and J.L. Qi provided additional specimens. S.L. Chen, J.Y. Li, and P. Gao wrote the manuscript and all authors participated in the revisions.
PY - 2022/5/11
Y1 - 2022/5/11
N2 - Defects in organic-inorganic hybrid perovskites (OIHPs) greatly influence their optoelectronic properties. Identification and better understanding of defects existing in OIHPs is an essential step towards fabricating high-performance perovskite solar cells. However, directly visualizing the defects is still a challenge for OIHPs due to their sensitivity during electron microscopy characterizations. Here, by using low dose scanning transmission electron microscopy techniques, we observe the common existence of antiphase boundary (APB) in CH3NH3PbI3 (MAPbI3), resolve its atomic structure, and correlate it to the electrical/ionic activities and structural instabilities. Such an APB is caused by the half-unit-cell shift of [PbI6]4− octahedron along the [100]/[010] direction, leading to the transformation from corner-sharing [PbI6]4− octahedron in bulk MAPbI3 into edge-sharing ones at the APB. Based on the identified atomic-scale configuration, we further carry out density functional theory calculations and reveal that the APB in MAPbI3 repels both electrons and holes while serves as a fast ion-migration channel, causing a rapid decomposition into PbI2 that is detrimental to optoelectronic performance. These findings provide valuable insights into the relationships between structures and optoelectronic properties of OIHPs and suggest that controlling the APB is essential for their stability.
AB - Defects in organic-inorganic hybrid perovskites (OIHPs) greatly influence their optoelectronic properties. Identification and better understanding of defects existing in OIHPs is an essential step towards fabricating high-performance perovskite solar cells. However, directly visualizing the defects is still a challenge for OIHPs due to their sensitivity during electron microscopy characterizations. Here, by using low dose scanning transmission electron microscopy techniques, we observe the common existence of antiphase boundary (APB) in CH3NH3PbI3 (MAPbI3), resolve its atomic structure, and correlate it to the electrical/ionic activities and structural instabilities. Such an APB is caused by the half-unit-cell shift of [PbI6]4− octahedron along the [100]/[010] direction, leading to the transformation from corner-sharing [PbI6]4− octahedron in bulk MAPbI3 into edge-sharing ones at the APB. Based on the identified atomic-scale configuration, we further carry out density functional theory calculations and reveal that the APB in MAPbI3 repels both electrons and holes while serves as a fast ion-migration channel, causing a rapid decomposition into PbI2 that is detrimental to optoelectronic performance. These findings provide valuable insights into the relationships between structures and optoelectronic properties of OIHPs and suggest that controlling the APB is essential for their stability.
UR - http://hdl.handle.net/10754/677998
UR - https://linkinghub.elsevier.com/retrieve/pii/S1359645422003913
UR - http://www.scopus.com/inward/record.url?scp=85129942290&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2022.118010
DO - 10.1016/j.actamat.2022.118010
M3 - Article
SN - 1359-6454
VL - 234
SP - 118010
JO - Acta Materialia
JF - Acta Materialia
ER -