Energy separation and carrier-phonon scattering in CdZnTe/ZnTe quantum dots on Si substrate

• PL intensity and decay time of CdZnTe/ZnTe QDs are evaluated by same model.
• Redistribution into multiple discrete levels plays an important role in carrier dynamics.
• Quantum confinement affects both the exciton-acoustic and optical phonons coupling.
• Energy separation between the discrete states is around 4.5 meV.
• Average energy of the optical phonons is about 18.5 meV.

We investigate the energy separation and carrier-phonon scattering in CdZnTe/ZnTe quantum dots on Si substrate. The quantum confinement results in an increase in acoustic phonon coupling and a reduction in optical phonon coupling. We describe the carrier dynamics behavior over the whole temperature using a model that includes discrete transitions and the escape of carriers in non-radiative processes. The energy separation between the discrete states is around 4.5 meV and the average energy of the optical phonons is about 18.5 meV. The slight increase in the decay time of the structure with increasing temperature is explained in terms of redistribution into multiple discrete levels.

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