Enhancement of photoluminescence in ZnS/ZnO quantum dots interfacial heterostructures
- Centre for Materials Science and Nano Devices, Department of Physics, SRM University, Kattankulathur 603 203, Chennai (India)
- UGC-DAE Consortium for Scientific Research (Kalpakkam node), Kalpakkam 603102 (India)
Highlights: ► ZnS/ZnO quantum dots (QDs) were synthesized by controlled oxidation of ZnS nanoparticles. ► Interfacial heterostructure formation of ZnS/ZnO QDs is seen in HRTEM. ► Enormous enhancement of UV emission (∼10 times) in ZnS/ZnO QDs heterostructure is observed. ► Phonon confinement effect is seen in the Raman spectrum. -- Abstract: ZnS/ZnO quantum dots (QDs) were synthesized by controlled oxidation of ZnS nanoparticles. HRTEM image showed small nanocrystals of size 4 nm and the magnified image of single quantum dot shows interfacial heterostructure formation. The optical absorption spectrum shows a blue shift of 0.19 and 0.23 eV for ZnO and ZnS QDs, respectively. This is due to the confinement of charge carries within the nanostructures. Enormous enhancement in UV emission (10 times) is reported which is attributed to interfacial heterostructure formation. Raman spectrum shows phonons of wurtzite ZnS and ZnO. Phonon confinement effect is seen in the Raman spectrum wherein LO phonon peaks of ZnS and ZnO are shifted towards lower wavenumber side and are broadened.
- OSTI ID:
- 22215759
- Journal Information:
- Materials Research Bulletin, Vol. 47, Issue 9; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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