Estudo optoestrutural de perovskitas de iodeto de césio e chumbo em vidro borossilicato: efeitos da dopagem com terras raras e nióbio

Abstract

In this work, the structural and optical properties of CsPbI3 perovskites embedded in a borosilicate glass matrix, doped with rare-earth ions (Nd3+, Er3+, Sm3+, and Ho3+) and co-doped with Nb⁵⁺, were investigated. The results show that increasing the Nb5+ concentration favors its incorporation into the glass matrix and promotes the formation of the cubic perovskite phase. The addition of rare-earth ions also contributes to the stabilization of this phase, although no dominant element could be identified. Raman spectroscopy confirmed the presence of vibrational modes associated with the SNAB glass matrix and the role of Nb5+ as a network modifier. Temperature-dependent photoluminescence spectra exhibited emission bands attributed to CsPbI3, with a maximum at ~720 nm (1.72 eV) at 77 K, shifting to ~700 nm (1.78 eV) with increasing temperature, accompanied by spectral broadening and thermal quenching. Among the investigated samples, the Er3+-doped compositions are the most promising, due to the effective stabilization of the cubic phase and their potential application as optical thermometers, exhibiting a relative sensitivity of 4.3% K-1. These results demonstrate that co-doping with Nb5+ and rare-earth ions is an efficient strategy to control the structural stability and optical properties of CsPbI3 perovskites embedded in glass matrices.