Temperature Dependence of Photoluminescence and Calculation of Activation Energy for Thermal Quenching in Cspbbr₃ Perovskite

This paper investigates the temperature dependence of the photoluminescence properties of inorganic perovskite CsPbBr₃. Nanoparticles were synthesized by a ligand-assisted method using CsBr and PbBr₂ as precursors, dimethyl sulfoxide as a solvent, and oleylamine and oleic acid as stabilizers. After purification by centrifugation with acetone, the samples were analyzed using a Shimadzu RF-6000 spectrofluorometer in the temperature range of 45–95 °C. With increasing temperature, the photoluminescence peak shifts from 448 nm (2.77 eV) at 45 °C to 567 nm (2.19 eV) at 95 °C. Simultaneously, the spectral line broadens from ~30 to ~40 nm (FWHM), and the emission intensity decreases by more than half. These changes result from band gap narrowing, enhanced electron–phonon coupling, and activation of defect states. The activation energy of non-radiative processes was calculated as Ea≈0.374 eV, consistent with literature data. The results clarify the mechanisms of thermal quenching in CsPbBr₃ and are relevant for perovskite-based optoelectronic devices.