Raman scattering in multilayer structures with CdTe quantum dots in ZnTe

Optical spectroscopy of CdTe/ZnTe quantum dot multilayers

“…5. Raman spectra of the samples with ZnTe spacer thickness of 10 and 50 ML basically coincided with the spectra of samples previously studied [10]. The bands at ∼ 120, ∼ 140, and ∼ 200 cm -1 are observed in the experiment.…”

“…The bands at ∼ 120, ∼ 140, and ∼ 200 cm -1 are observed in the experiment. It was shown in [10] that the first two bands are caused by the mode of QD confined phonons and the symmetrical Coulomb (interface) mode of QD, respectively. The band at ∼ 200 cm -1 is related to ZnTe LO phonons.…”

“…5). As in [10] the bands at 126.5 and 142 cm -1 we assign to the mode of QD confined phonons and to the symmetrical Coulomb mode of QDs, respectively. It is possible that a new band at 147 cm -1 is associated with the symmetrical mode of a QD pair in which dipole moments of QDs vibrate in opposite directions.…”

“…In this model (which is an extention of the model used in [10]) Raman-active vibrational mode frequencies are derived from boundary conditions: continuity of the potential and the normal component of electric induction across the surfaces of two QDs. The materials of QDs (CdTe) and environment (ZnTe) are characterized by their frequencydependent dielectric functions.…”

Far-infrared spectroscopy of CdTe/ZnTe self-assembled quantum dots

“…Values for ω LO are even lower than in the strained bulk, where ω LO is 203-208.5 cm −1 , according to Refs. [14][15][16]. Alloying of ZnTe and CdTe in interface layers can be the reason for additional shifting of ZnTe-like ω LO .…”