Onion-like (CdSe)ZnS/CdSe/ZnS quantum-dot-quantum-well heteronanocrystals for investigation of multi-color emission.
We investigate multi-color spontaneous emission from quantum-dot- quantum-well heteronanocrystals made of onion-like (CdSe)ZnS/CdSe/ZnS (core)shell/shell/shell structures, with our theoretical results explaining experimental measurements for the first time. In such multi-layered heteronanocrystals, we discover that the carrier localization is tuned from type-1-like to type-2-like localization by controlling CdSe and ZnS shell thicknesses, and that 3-monolayer ZnS barriers are not necessarily sufficient for carrier localization, unlike in conventional (CdSe)ZnS (core)shell structures. We demonstrate that exciton localization in distinct layers of (CdSe)ZnS/CdSe/ZnS heteronanocrystals with high transition probability (for n=1 states in CdSe core and n=2 states in CdSe shell) is key to their multi-color emission.
Department of Electrical and Electronics Engineering, Nanotechnology Research Center, and Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, Turkey TR-06800.
Sedat
S
Nizamoglu
Hilmi Volkan
HV
Demir
D019187:Cadmium Compounds / Q000737:chemistry*; D003124:Colorimetry / Q000379:methods*; D003460:Crystallization / Q000379:methods*; D008422:Materials Testing; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D017967:Zinc Compounds / Q000737:chemistry*
D019187:Cadmium Compounds; D018036:Selenium Compounds; D017967:Zinc Compounds; C058667:cadmium selenide; C044696:zinc selenide