Proceedings of the Korean Vacuum Society Conference (한국진공학회:학술대회논문집)
- 2015.08a
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- Pages.191.2-191.2
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- 2015
Energy separation and carrier-phonon scattering in CdZnTe/ZnTe quantum dots on Si substrate
Abstract
Details of carrier dynamics in self-assembled quantum dots (QDs) with a particular attention to nonradiative processes are not only interesting for fundamental physics, but it is also relevant to performance of optoelectronic devices and the exploitation of nanocrystals in practical applications. In general, the possible processes in such systems can be considered as radiative relaxation, carrier transfer between dots of different dimensions, Auger nonradiactive scattering, thermal escape from the dot, and trapping in surface and/or defects states. Authors of recent studies have proposed a mechanism for the carrier dynamics of time-resolved photoluminescence CdTe (a type II-VI QDs) systems. This mechanism involves the activation of phonons mediated by electron-phonon interactions. Confinement of both electrons and holes is strongly dependent on the thermal escape process, which can include multi-longitudinal optical phonon absorption resulting from carriers trapped in QD surface defects. Furthermore, the discrete quantized energies in the QD density of states (1S, 2S, 1P, etc.) arise mainly from
Keywords
- Quantum dots;
- Cadmium zinc telluride;
- Silicon substrate;
- Energy separation;
- Carrier-phonon scattering