First principle studies of rubidium lead halides towards photovoltaic application

Abstract

All inorganic perovskites have attracted enormous attention of late owing to their outstanding applications in photovoltaic area including highly stable perovskite solar cells. In-depth understanding of the optoelectronic and transport properties of such materials are vital for practical implementation of the same. The carrier transport properties of the electronic devices based on perovskite materials significantly depend on the effective mass of the respective charge carriers. Here, we have performed first principle calculations with FP-LAPW method for the orthorhombic rubidium lead halides (RbPbX3, where X = I, Br, Cl) to study the optoelectronic and transport properties. The reduced effective mass is found to be minimum for RbPbI3, suggesting an efficient charge carrier transport in the corresponding material. Our calculated values such as the dielectric constants, refractive indices, absorption coefficients and reflectivities show good agreement with reported experimental data. Excitons for RbPbI3 and RbPbBr3 are of Mott–Wannier type while it is of Frenkel type for RbPbCl3. Moreover, estimated band edges of RbPbI3 show a favorable charge carrier transport when it is used with TiO2. Spectroscopic limited maximum efficiency (SLME) of 11.59% can be achieved for 500 nm thick single junction solar cell of RbPbI3.