Composition-dependent Trap Distributions in CdSe a
Post# of 22465
Posted On: 05/24/2016 1:49:01 AM
Composition-dependent Trap Distributions in CdSe and InP Quantum Dots Probed Using Photoluminescence Blinking Dynamics
Although Group II-VI quantum dots (QDs) have attracted much attention for their wide range of applications in QD-based devices, the presence of toxic ions in II-VI QDs raises environmental concerns. To fulfill the demands of nontoxic QDs, synthetic routes for III-V QDs have been developed . However, only little comparative analyses on optical properties of III-V QDs have been performed. In this study, the composition-related energetic trap distributions have been explored by using three different types of core/multishell QDs: CdSe-CdS (CdSe/CdS/ZnS), InP-ZnSe (InP/ZnSe/ZnS), and InP-GaP (InP/GaP/ZnS). It was shown that CdSe-CdS QDs have much larger trap densities than InP-Shell QDs at higher energy states (at least 1 Eg (band gap energy) above the lowest conduction band edge) based on probability density plots and Auger ionization efficiences which are determined by analyses of photoluminescence blinking dynamics. This result suggests that the composition of encapsulated QDs is closely associated with charge trapping processes, and also provides an insight into the development of environmentally more friendly QD-based devices.
http://pubs.rsc.org/en/content/articlelanding...ivAbstract
Although Group II-VI quantum dots (QDs) have attracted much attention for their wide range of applications in QD-based devices, the presence of toxic ions in II-VI QDs raises environmental concerns. To fulfill the demands of nontoxic QDs, synthetic routes for III-V QDs have been developed . However, only little comparative analyses on optical properties of III-V QDs have been performed. In this study, the composition-related energetic trap distributions have been explored by using three different types of core/multishell QDs: CdSe-CdS (CdSe/CdS/ZnS), InP-ZnSe (InP/ZnSe/ZnS), and InP-GaP (InP/GaP/ZnS). It was shown that CdSe-CdS QDs have much larger trap densities than InP-Shell QDs at higher energy states (at least 1 Eg (band gap energy) above the lowest conduction band edge) based on probability density plots and Auger ionization efficiences which are determined by analyses of photoluminescence blinking dynamics. This result suggests that the composition of encapsulated QDs is closely associated with charge trapping processes, and also provides an insight into the development of environmentally more friendly QD-based devices.
http://pubs.rsc.org/en/content/articlelanding...ivAbstract
(0)
(0)