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Influence of ZnTe separation layer thickness on optical properties in CdTe/ZnTe double quantum dots on Si substrates
摘要： We investigate the influence of the ZnTe separation layer thickness on the photoluminescence (PL) dynamics of CdTe/ZnTe double quantum dots (DQDs) on Si substrates. The results clarify that the DQD's structure effectively improves the limit of the carrier collection and the thermal stability of the corresponding single-layer QDs. The unusual temperature-dependent PL is explained using the single model for thermal redistribution of carrier states. This model indicates that the main nonradiative process at high temperatures is caused by scattering via multiphonons with longitudinal optical phonon energy of about 19–21.3 meV. The confinement-induced mixing and electron-carrier coupling effects cause blue-shift and enhanced PL intensity. We propose that the separation layer controls carrier dynamics in optoelectronic devices by modulating the thermal escape and e-h pairs in the intermixing layers.
关键词： Quantum dots,Silicon substrate,Cadmium telluride,Thermal escape,Carrier confinement
更新于2025-09-16 10:30:52
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Spectroscopic monitoring of the evolution of size and structural defects in kinetic growth of CdSe quantum dots
摘要： We report here on the exciton-phonon coupling and role of trap states formed at the interface of structural dislocations in CdSe quantum dots (QDs) synthesized by kinetic growth method. Even though non-luminescing, our studies recognize their signatures in the temperature dependent photoluminescence characteristics of lowest QD excitonic state and have some useful implications for structural quality of thus synthesized QDs. We have explained the observed temperature dependence of PL intensity in terms of a simple model taking account of different radiative and nonradiative recombination processes as well as carrier trapping/detrapping and determined the depth of potential well formed due to such long range defects. Our studies indicate the presence of such defect states only in QD samples size sorted by aliquoting at intermediate intervals during the reaction and do not appear when the reaction proceeds uninterrupted.
关键词： Temperature dependent photoluminescence,Exciton-phonon coupling,Thermal escape,CdSe Quantum Dots
更新于2025-09-16 10:30:52