A DFT study of structural, electronic, optical, mechanical, thermoelectric, and magnetic properties of Pb-halide perovskites LiPbX3 (X = Cl, Br, and I) for photovoltaic applications

The structural, electronic, optical, mechanical, thermal, and magnetic properties of Pb-based cubic perovskites LiPbX3 (X = Cl, Br, and I) were evaluated by using the LDA + U technique within the CASTEP code. The calculated lattice constants of studied materials are found 5.8048 & ANGS;, 6.0707 & ANGS; and 6.3792 & ANGS; for LiPbCl3, LiPbBr3 and LiPbI3, respectively. The electronic properties show that all three materials are semiconductor in nature. The calculated energy band gaps are 1.801 eV, 2.337 eV and 1.943 eV for LiPbCl3, LiPbBr3 and LiPbI3, respectively. The optical properties of all three materials are discussed for the photon energy from 0 to 25 eV to explain interaction of light with the material. The mechanical properties reveal that all three materials possess a ductile behavior. The thermal properties revealed that the value of Debye temperature is 169 K, 128 K and 87 K for LiPbBr3, LiPbCl3 and LiPbI3, respectively. The magnetic properties suggest that the total magnetic dipole of studied materials is zero and thus all three materials behave as antiferromagnetic materials. The theoretical power conversion efficiency is 24.37%, 16.17% and 08.14% for LiPbI3, LiPbBr3 and LiPCl3, respectively. The electronic and optical properties reveal that all considered materials are suitable for photovoltaic and optoelectronics applications.