Investigation on the Cu-Dopant-Induced Modulation Effect on the Optoelectronic Efficiency and the Stability of CsPbBr₃ Perovskites

Abstract

This study explores the use of Cu dopant to improve the optoelectronic properties and stability of CsPbX3 perovskites for blue-light-emitting diode material. The addition of Cu causes the metal octahedron of orthorhombic CsPbBr3 to shrink, which relaxes the lattice strain from the distortion and twisting of the [PbX6] octahedron and reduces energy from Jahn–Teller effects. A crystal orbital Hamilton population (COHP) analysis reveals that the Cu-Br bond in the [CuX6] octahedron has a higher integrated projected COHP (IpCOHP), and the strong hybridization between the Cu-3d and Br-4p bond enhances the bond interaction and the whole crystalline lattice. The addition of Cu dopants in CsPbBr3 perovskites results in a stronger framework that suppresses intrinsic defects like Br vacancies, leading to enhanced photoluminescence (PL) performance. Additionally, the Cu-3d orbitals contribute to the valence band and increase the band gap, resulting in a blue shift of the luminescence from Cu-doped CsPbBr3. These findings indicate that Cu dopants significantly improve the luminescence efficiency and the stability of CsPbBr3 perovskites, making them suitable for blue light LED applications.

Keywords

• CsPbBr₃ perovskites
• Cu dopant
• crystal orbital Hamilton population
• blue luminescence
• stability