Photovoltaic and related properties of Sn-doped disordered CsPbxSn1−xBr3 perovskite: a first-principles calculation

• Published in: Journal of materials science 2022-11, Vol.57 (42), p.19846-19856
• Main Authors: Shi, Hai-Zheng, Jing, Yue, Li, Wen-Hao, Wang, Ci, Jia, Bao-Nan, Ren, Jing
• Format: Article
• Language: English
• Subjects: Alternative energy sources; Characterization and Evaluation of Materials; Chemical composition; Chemistry and Materials Science; Classical Mechanics; Computation & Theory; Crystal defects; Crystallography and Scattering Methods; Dipole moments; Efficiency; Electronic structure; Electrons; Energy conversion efficiency; Energy gap; Energy resources; First principles; Free energy; Heat of formation; Laboratories; Materials Science; Mathematical analysis; Perovskites; Photovoltaic cells; Polymer Sciences; Solid Mechanics; Tin; Toxicity; Valence band
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-022-07883-5

Perovskite CsPbBr 3 possesses high photovoltaic capability but limited application on account of the toxicity of lead. Sn-doped all-inorganic perovskites CsPb x Sn 1− x Br 3 are designed in order to achieve comprehensive high photovoltaic performance with low toxicity, which is under great influence of chemical compositions and defects. In this paper, the electronic structures and other photovoltaic-related properties of CsPbBr 3 and CsSnBr 3 are studied by using first-principles method with different functionals. The calculation results show that CsSnBr 3 has a lower bandgap than that of CsPbBr 3 . The transition dipole moment of CsPbBr 3 is more even, and the effective masses of electrons and holes are slightly larger than those of CsSnBr 3 . By calculating the defect formation energies, the types and properties of intrinsic defects of these two crystals are compared, and their effects on photovoltaic-related properties are analyzed. Different proportions of disordered CsPb x Sn 1− x Br 3 crystals constructed by special Quasirandom structure (SQS) method are designed to observe the effect of Sn contents on the electronic structure, and effective masses of electrons and holes of CsPbBr 3 , and CsPb 0.50 (Ba/Ca) 0.50 Br 3 are also calculated as a reference. It has been proved that the presence of Sn affects the orbital composition at the valence band maximum of the crystal, making Sn- 5s orbitals participate in the formation of valence band maximum, which raises the energy of crystal valence band maximum and reduces the bandgap of the system. The doping of Sn decreases the toxicity of perovskite on the premise of considering the power conversion efficiency, which may provide a theoretical basis for the development of CsPb x Sn 1− x Br 3 photovoltaic materials.