Investigation of TM (TM=Mg, Cu) doping effect on the luminescence performance of CsPbCl₃ from a first-principles investigation

Abstract

The inorganic perovskite CsPbCl3 has raised great concern in recent years due to its great tunability of luminescence properties via impurity doping. However, the blue-emitting mechanism of the impurity-doped CsPbCl3 is unexplored. In this work, we focus on the structural, electronic, and optical properties of CsPb1-x TM x Cl3 (TM=Mg, Cu; x = 0, 0.037, 0.074) based on the first-principles calculations. It is indicated that TM doping decreases the lattice parameter, deforms octahedral structure, and improves the stability of CsPbCl3. The increased direct bandgap values and unique TM energy levels occupation show that the doped systems behave only blue-emitting well. The Mg-s and Cu-3d (eg) states out the bandgaps are close to the valence band edge and conduction band edge respectively, both promoting the carrier radiation recombination. Furthermore, the density of states analyses demonstrates that the enhanced emission of TM-doped CsPbCl3 benefits from the TM different electronic configurations and the different hybridization ways (Mg 3s/Cl 3p, Cu eg/Cl 3p), producing more carriers with increasing x respectively. The obtained optical properties imply that the TM-doped systems exhibit significant optical absorption and high carrier mobilities, promoting excellent luminescence efficiency. Our work explains the blue-emitting mechanism of the TM-doped CsPbCl3, providing a prospective strategy for designing highly efficient blue-emitting devices for optoelectronic applications based on the available parent materials by modulating the bandgap, synergistic relation of impurity energy level and band edge, and optical property.