The effects of heteroatoms-doping on the stability, electronic and magnetic properties of CH3NH3PbI3 perovskite

Abstract

Organic and inorganic lead halogen calcium titanium ore has become interesting candidates for next-generation solar cells material especially in recent years, making CH3NH3PbI3 based perovskite develop particularly rapidly. Here, it is demonstrated that six transition metals, Fe, Co, Ni, Cu, Ru, and Rh atoms, can exchange with Pb atom in CH3NH3PbI3 perovskite structures based on the classical concept of factors with tolerance, octahedral and the binding energy. The fact that the transition metal atoms doped into CH3NH3PbI3 based perovskite have lattice constants similar with the lead perovskite, indicating the reliability of the doping system. In this paper, the electronic and magnetic properties of the six transition metals doped into CH3NH3PbI3 perovskites have been investigated, thus these compounds have been predicted to exist as stable perovskite materials. Considering spin effects, all six doping systems generate magnetic properties. At the same time, applying ferromagnetism and anti-ferromagnetism into the doping systems, the nature of the magnetic ground state has been calculated. Treating the energies of ferromagnetism and anti-ferromagnetism, Co, Ni, Cu, and Rh atoms exhibit anti-ferromagnetism, and Fe, Ru atomic doped systems exhibit ferromagnetism. The charge densities were plotted for the CH3NH3PbI3 perovskites, and as the electronegativity of the metal atoms increased, more charge was concentrated on the metal cations, and the chemical bonding properties inside the crystals were changed. It can be found that stable transition metals- Pb hybrid perovskite with suitable band gaps can be obtained by replacing the Pb atoms with transition metal atoms, and the incorporation of transition metal atoms protects the problem of easy degradation and toxicity of Pb atoms to some extent. This study aims to provide experiments and theoretical guidance for the search of new lead-free perovskite materials.