Pressure Raman scattering of CdTe quantum dots

Abstract

A series of zinc-blende CdTe quantum dots in glass was investigated using Raman scattering and luminescence. The dot size was controlled by varying the annealing conditions. Luminescence was employed as a probe for quality of the sample and its adequacy for resonance. Resonant Raman spectra at the lowest confined energy levels of the quantum dots were obtained in function of the pressure in the range 1 bar to 4.6 GPa. The upper limit was established by a phase transition probably to NaCl structure, simultaneous with disappearance of Raman signal. In the latter phase, first-order Raman scattering is forbidden. The Gr\"uneisen parameter for the LO phonon of CdTe quantum dots is given.