Study of the Electron-Phonon Coupling in PbS/MnTe Quantum Dots Based on Temperature-Dependent Photoluminescence

The temperature dependence of photoluminescence (PL) emission is a valuable tool for investigating carrier localization, recombination, and carrier-phonon interactions. Herein, electron-phonon couplings in lead sulfide (PbS) quantum dots (QDs) and lead sulfide/manganese tellurite (PbS/MnTe) QDs is reported. The effect of temperature on the PL emission of PbS and PbS/MnTe was explored within a temperature range of 10 to 300 K. When temperature increased, PL emission was blue-shifted due to the confinement effect. The gradual broadening of the full width at half maximum (FWHM) with increasing temperature indicates electron-phonon interactions. An analysis based on the Boson model revealed that the values of the exciton acoustic phonon coupling coefficient, sigma, and temperature-dependent linewidth, gamma, for PbS/MnTe were larger than those for PbS, indicating stronger exciton longitudinal-optical-phonon coupling in the compound structure.