Temperature-dependent Mn2+ emission of co-doped CsPb2 (BrCl)5 Perovskite nanocrystals

We prepared codoped CsPb 2 (BrCl) 5 nanocrystal (NC) films by varying the Cu/Mn molar ratio using a facile two-step solution method. The Mn 2+ emission peak is studied in the temperature range of 80–300 K. Strong electron–optical-phonon coupling causes an anomalous blueshift and linewidth broadening of the Mn 2+ emission peak with increasing temperature. The average optical-phonon energy is approximately 50 meV. The activation energy reaches 79.32 meV, indicating that the introduction of Cu 2+ in Mn-doped CsPb 2 (BrCl) 5 NCs greatly enhances the energy transfer (ET) from the perovskite NC host to Mn 2+ , increasing the Mn 2+ emission intensity. A clear understanding of the optical mechanism of Mn 2+ emission is of great significance for the widespread application of codoped CsPb 2 (BrCl) 5 NCs in optoelectronic devices.