Optoelectronic performance of perovskite Cs2KMI6 (M = Ga, In) based on high-throughput screening and first-principles calculations

Fangfang Qi; Xin Lv; Jinhui Song; Xifeng Fu; Lingyi Meng; Can-Zhong Lu

doi:10.1039/d3cp00732d

Optoelectronic performance of perovskite Cs₂KMI₆ (M = Ga, In) based on high-throughput screening and first-principles calculations

Phys Chem Chem Phys. 2023 Apr 26;25(16):11484-11492. doi: 10.1039/d3cp00732d.

Authors

Fangfang Qi^{1

2

3}, Xin Lv^{1

3}, Jinhui Song^{1

3}, Xifeng Fu^{1

2

3}, Lingyi Meng^{1

2

3}, Can-Zhong Lu^{1

2

3

4}

Affiliations

¹ CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China. lymeng@fjirsm.ac.cn.
² College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, P. R. China.
³ Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, 361021, P. R. China.
⁴ University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.

PMID: 37039011
DOI: 10.1039/d3cp00732d

Abstract

Developing novel lead-free perovskite materials with suitable bandgaps and superior thermal stability is crucial to boost their applications in next-generation photovoltaic technologies. High throughput screening combined with the first principles method can accurately and effectively screen out promising perovskites. Herein, we select two lead-free all-inorganic halide double perovskite materials Cs₂KMI₆ (M = Ga, In) from 1026 compounds with the criteria including appropriate structure factors, positive decomposition energies, and suitable direct bandgaps. We investigated the thermal and mechanical stability, geometric and electronic structures, photoelectric properties, and defect formation energies for both perovskites Cs₂KMI₆ (M = Ga, In). They can exhibit excellent structural formability and stability through the analysis of structure factors, elastic constants, and stable chemical potential regions. In addition, we investigate the defect effects of Cs₂KMI₆ (M = Ga, In) on the photovoltaic performance by evaluating the defect formation energies and transition energy levels. Based on the HSE06 functional, we calculated the energy band structures of these two compounds and demonstrate the direct bandgaps of 1.69 eV (HSE06) and 2.16 eV (HSE06) for Cs₂KGaI₆ and Cs₂KInI₆, respectively. Moreover, we predicted excellent spectroscopic limited maximum efficiencies (SLMEs) of these two perovskites with high light absorption coefficients (around 10⁵ cm^-1), for instance, the SLME of Cs₂KGaI₆ can reach as high as 28.39%.