Abstract
It has been clarified that the two excitations, the small energy excitation in the two-level system, and the confined acoustic phonons, determine the low-temperature dependence of the homogeneous linewidth in CuBr and CdSe quantum dots. The former dominates the temperature dependence below 15 K for CuBr quantum dots, causing a difference in temperature dependence between NaBr and glass matrix samples. Above 15 K, the latter makes the same nonlinear temperature dependence. The contribution of confined acoustic phonons is also confirmed in CdSe quantum dots above 10 K as a deviation from the linear temperature dependence. These results closely resemble those previously reported for CuCl quantum dots, \\citerf4 reflecting the universal influence of surface-related effects and confined phonon scattering on the dephasing process of semiconductor quantum dots in matrices.
