Manipulating the Mixed-Perovskite Crystallization Pathway Unveiled by In Situ GIWAXS

© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bibliographische Detailangaben
Veröffentlicht in:Advanced materials (Deerfield Beach, Fla.). - 1998. - 31(2019), 25 vom: 05. Juni, Seite e1901284
1. Verfasser: Qin, Minchao (VerfasserIn)
Weitere Verfasser: Tse, Kinfai, Lau, Tsz-Ki, Li, Yuhao, Su, Chun-Jen, Yang, Guang, Chen, Jiehuan, Zhu, Junyi, Jeng, U-Ser, Li, Gang, Chen, Hongzheng, Lu, Xinhui
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2019
Zugriff auf das übergeordnete Werk:Advanced materials (Deerfield Beach, Fla.)
Schlagworte:Journal Article Cs doping annealing window crystallization pathways in situ GIWAXS perovskite solar cells
Beschreibung
Zusammenfassung:© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Mixed perovskites have achieved substantial successes in boosting solar cell efficiency, but the complicated perovskite crystal formation pathway remains mysterious. Here, the detailed crystallization process of mixed perovskites (FA0.83 MA0.17 Pb(I0.83 Br0.17 )3 ) during spin-coating is revealed by in situ grazing-incidence wide-angle X-ray scattering measurements, and three phase-formation stages are identified: I) precursor solution; II) hexagonal δ-phase (2H); and III) complex phases including hexagonal polytypes (4H, 6H), MAI-PbI2 -DMSO intermediate phases, and perovskite α-phase. The correlated device performance and ex situ characterizations suggest the existence of an "annealing window" covering the duration of stage II. The spin-coated film should be annealed within the annealing window to avoid the formation of hexagonal polytypes during the perovskite crystallization process, thus achieving a good device performance. Remarkably, the crystallization pathway can be manipulated by incorporating Cs+ ions in mixed perovskites. Combined with density functional theory calculations, the perovskite system with sufficient Cs+ will bypass the formation of secondary phases in stage III by promoting the formation of α-phase both kinetically and thermodynamically, thereby significantly extending the annealing window. This study provides underlying reasons of the time sensitivity of fabricating mixed-perovskite devices and insightful guidelines for manipulating the perovskite crystallization pathways toward higher performance
Beschreibung:Date Revised 01.10.2020
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1521-4095
DOI:10.1002/adma.201901284