Sn-based halide perovskites are the most promising alternatives for developing Pb-free perovskite solar cell materials. However, the stability of Sn halide perovskites is the biggest concern for future developments. The phase stability and the doping-level control should be resolved for Sn perovskites to compete with Pb-based analogs. Herein, interstitial engineering is used to enhance the stability of Sn-based halide perovskites using alkali metals through ab initio calculations and controlled experiments. This study reveals that alkali metal interstitials can promote the performance of Sn perovskites by controlling their phase stability, suppressing free carrier density, and locking lattice vibration. K+ shows the most promising behavior among alkali–metal cations in terms of phase stabilization and defect formation energy.
Bibliographical noteFunding Information:
This research was supported by National R&D Program through the National Research Foundation of Korea (NRF) (NRF‐2015M1A2A2055836, NRF‐2018R1A2B6007888, NRF‐2017M3A7B4041698) and New & Renewable Energy Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) (grant no. 20183010013820).
© 2020 Wiley-VCH GmbH
Copyright 2020 Elsevier B.V., All rights reserved.
- alkali metals
- density functional theory
- tin perovskites
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Energy Engineering and Power Technology
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering