TY - JOUR
T1 - Unveiling a Key Intermediate in Solvent Vapor Postannealing to Enlarge Crystalline Domains of Organometal Halide Perovskite Films
AU - Xiao, Shuang
AU - Bai, Yang
AU - Meng, Xiangyue
AU - Zhang, Teng
AU - Chen, Haining
AU - Zheng, Xiaoli
AU - Hu, Chen
AU - Qu, Yongquan
AU - Yang, Shihe
N1 - Publisher Copyright:
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2017/3/24
Y1 - 2017/3/24
N2 - Hybrid organic/inorganic perovskite solar cells (PSCs) have shown great potential in meeting the future challenges in energy and environment. Solvent-vapor-assisted posttreatment strategies are developed to improve the perovskite film quality for achieving higher efficiency. However, the intrinsic working mechanisms of these strategies have not been well understood yet. This study identifies an MA2Pb3I8(DMSO)2 intermediate phase formed during the annealing process of methylammonium lead triiodide in dimethyl sulfoxide (DMSO) atmosphere and located the reaction sites at perovskite grain boundaries by observing and rationalizing the growth of nanorods of the intermediate. This enables us to propose and validate an intermediate-assisted grain-coarsening model, which highlights the activation energy reduction for grain boundary migration. Leveraging this mechanism, this study uses MABr/DMSO mixed vapor to further enhance grain boundary migration kinetics and successfully obtain even larger grains, leading to an impressive improvement in power conversion efficiency (17.64%) relative to the pristine PSCs (15.13%). The revelation of grain boundary migration-assisted grain growth provides a guide for the future development of polycrystalline perovskite thin-film solar cells.
AB - Hybrid organic/inorganic perovskite solar cells (PSCs) have shown great potential in meeting the future challenges in energy and environment. Solvent-vapor-assisted posttreatment strategies are developed to improve the perovskite film quality for achieving higher efficiency. However, the intrinsic working mechanisms of these strategies have not been well understood yet. This study identifies an MA2Pb3I8(DMSO)2 intermediate phase formed during the annealing process of methylammonium lead triiodide in dimethyl sulfoxide (DMSO) atmosphere and located the reaction sites at perovskite grain boundaries by observing and rationalizing the growth of nanorods of the intermediate. This enables us to propose and validate an intermediate-assisted grain-coarsening model, which highlights the activation energy reduction for grain boundary migration. Leveraging this mechanism, this study uses MABr/DMSO mixed vapor to further enhance grain boundary migration kinetics and successfully obtain even larger grains, leading to an impressive improvement in power conversion efficiency (17.64%) relative to the pristine PSCs (15.13%). The revelation of grain boundary migration-assisted grain growth provides a guide for the future development of polycrystalline perovskite thin-film solar cells.
KW - Br embedment
KW - grain boundary migration
KW - large perovskite domain
KW - perovskite solar cells
KW - solvent vapor anneal
UR - http://www.scopus.com/inward/record.url?scp=85012048723&partnerID=8YFLogxK
U2 - 10.1002/adfm.201604944
DO - 10.1002/adfm.201604944
M3 - Article
AN - SCOPUS:85012048723
SN - 1616-301X
VL - 27
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 12
M1 - 1604944
ER -