Abstract
Two-step-fabricated FAPbI3-based perovskites have attracted increasing attention because of their excellent film quality and reproducibility. However, the underlying film formation mechanism remains mysterious. Here, the crystallization kinetics of a benchmark FAPbI3-based perovskite film with sequential A-site doping of Cs+ and GA+ is revealed by in situ X-ray scattering and first-principles calculations. Incorporating Cs+ in the first step induces an alternative pathway from δ-CsPbI3 to perovskite α-phase, which is energetically more favorable than the conventional pathways from PbI2. However, pinholes are formed due to the nonuniform nucleation with sparse δ-CsPbI3 crystals. Fortunately, incorporating GA+ in the second step can not only promote the phase transition from δ-CsPbI3 to the perovskite α-phase, but also eliminate pinholes via Ostwald ripening and enhanced grain boundary migration, thus boosting efficiencies of perovskite solar cells over 23%. This work demonstrates the unprecedented advantage of the two-step process over the one-step process, allowing a precise control of the perovskite crystallization kinetics by decoupling the crystal nucleation and growth process.
Original language | English |
---|---|
Article number | 2004630 |
Number of pages | 11 |
Journal | Advanced Materials |
Volume | 32 |
Issue number | 42 |
Early online date | 16 Sept 2020 |
DOIs | |
Publication status | Published - 20 Oct 2020 |
Funding
M.Q. and H.X. contributed equally to this work. The authors are grateful for the beam time and technical supports provided by 23A SWAXS beamline at NSRRC, Hsinchu. The authors acknowledge the financial support from the Research Grant Council of Hong Kong (RGC) (General Research Fund No. 14314216). H.X. acknowledges the funding from the China Scholarship Council (CSC). S.T. acknowledges funding by the Computational Sciences for Energy Research (CSER) tenure track program of Shell and NWO (Project number 15CST04-2), The Netherlands. G.L. thanks funding from RGC (CRF Group Research Grant C5037-18G). M.Q. and H.X. contributed equally to this work. The authors are grateful for the beam time and technical supports provided by 23A SWAXS beamline at NSRRC, Hsinchu. The authors acknowledge the financial support from the Research Grant Council of Hong Kong (RGC) (General Research Fund No. 14314216). H.X. acknowledges the funding from the China Scholarship Council (CSC). S.T. acknowledges funding by the Computational Sciences for Energy Research (CSER) tenure track program of Shell and NWO (Project number 15CST04‐2), The Netherlands. G.L. thanks funding from RGC (CRF Group Research Grant C5037‐18G).
Funders | Funder number |
---|---|
Shell | |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek | 15CST04‐2 |
China Scholarship Council |
Keywords
- crystallization kinetics
- perovskite solar cells
- reaction enthalpy
- sequential A-site doping
- two-step method
Fingerprint
Dive into the research topics of 'Precise Control of Perovskite Crystallization Kinetics via Sequential A-Site Doping'. Together they form a unique fingerprint.Datasets
-
Crystallization of sequentially deposited perovskite films
Qin, M. (Creator), Xue, H. (Creator), Zhang, H. (Creator), Hu, H. (Creator), Liu, K. (Creator), Li, Y. (Creator), Qin, Z. (Creator), Ma, J. (Creator), Zhu, H. (Creator), Yan, K. (Creator), Fang, G. (Creator), Li, G. (Creator), Jeng, U.-S. (Creator), Brocks, G. (Creator), Tao, S. (Creator) & Lu, X. (Creator), CUHK Research Data Repository, 23 Nov 2021
DOI: 10.48668/YJXBPO, https://researchdata.cuhk.edu.hk/citation?persistentId=doi:10.48668/YJXBPO
Dataset