Optoelectronics and thermoelectric response of halide-based perovskites CsXY3 (X = Sn and Pb; Y = Cl, Br and I) semiconductors for solar cells and renewable energy

Abstract

The aim of this research paper is designed to explore a systematic comparison of structural, elastic, thermal, electronic, optical, and thermoelectric responses of halide-based cubic perovskites CsXY₃(X = Sn and Pb; Y = Cl, Br and I) semiconductors for their potential applications in optoelectronic and thermoelectric generators. Density functional theory (DFT) is used in the present work using first-principle calculations based on the full potential linearized augmented plane wave (FP-LAPW) method with WC-GGA and mBJ as exchange correlation potentials. Moreover, the thermoelectric properties of these compounds are also explored using the BoltzTrap code. The calculated structural parameters are consistent with previous experimental and theoretical results. Bulk modulus and ground-state energy decrease in both groups from Cl to I. Elastic properties show the ductile nature of these compounds except CsSnI₃. Electronic properties show that these compounds are semiconductor with direct band gap of 1.9 eV for CsPbCl₃, 1.6 eV for CsPbBr₃, 1.3 eV for CsPbI₃, 0.8 eV for CsSnCl₃, 0.4 eV for CsSnBr₃, and 0.15 eV for CsSnI₃ respectively. Optical properties like dielectric constant, refractive index, and optical conductivity, and absorption coefficients are calculated up to photon energy of 25 eV. The fluctuation of Seebeck coefficient S, electrical conductivity (σ/τ), electronic thermal conductivity (κ/τ), and thermoelectric power factor PF with respect to temperature is also studied. A comprehensive analysis of the optoelectronics and thermoelectric nature with a given band gaps was carried out, reflecting the uses of CsXY₃ (X = Sn and Pb Y = Cl, Br and I) compounds in optoelectronic and thermoelectric generators. Moreover, the super luminescent nature at high photon energy and the strong absorption in the infrared, visible, and ultraviolet energy ranges were also explored in details.