Temperature dependence of properties of Mn-doped nanocrystals with different binding symmetry

Abstract

We report the temperature dependence of photoluminescent properties of Mn-doped nanocrystals (NCs) with different binding symmetry. The photoluminescence peaks of Mn2+ ions shift to shorter wavelength with increasing temperatures, resulting from the reduction of crystal field. Further evidence for temperature-dependent crystal field variety is demonstrated by electronic paramagnetic resonance (EPR) spectra. Additionally, the inflexion temperature of the excited state lifetimes increases from 170K (Sample I) to 220K (Sample IV), which is speculated to be resulted from the easily affected wave function overlap due to thermal lattice expansion in more symmetrical binding Mn-doped NCs.