Interface effects and relaxation processes in nanocomposites based on CdSe/ZnS semiconductor quantum dots and porphyrin molecules
Controllable self-assembly and properties of nanocomposites based on CdSe/ZnS semiconductor quantum dots (QDs) and tetrapyridylporphyrin molecules (H{sub 2}P) as well as the dynamics of relaxation processes in these systems were studied for solutions and single nanoobjects in the temperature range of 77–295 K. It was proved that the formation of surface states of different nature is crucial to nonradiative relaxation of exciton excitation in QDs. The efficiency of QD→Н{sub 2}Р energy transfer was shown to be at most 10–15%. Regularities of photoluminescence (PL) quenching for QDs in nanocomposites in solutions of different polarity correlate with the dependences of PL blinking for single QDs. A scheme was proposed of excited states and main relaxation channels of exciton excitation energy in semiconductor QDs and QD–Н{sub 2}Р nanocomposites.
- OSTI ID:
- 22863323
- Journal Information:
- Russian Chemical Bulletin, Journal Name: Russian Chemical Bulletin Journal Issue: 7 Vol. 67; ISSN RCBUEY; ISSN 1066-5285
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
77 NANOSCIENCE AND NANOTECHNOLOGY
CADMIUM SELENIDES
ENERGY TRANSFER
EXCITATION
EXCITED STATES
EXCITONS
NANOCOMPOSITES
PHOTOLUMINESCENCE
PORPHYRINS
QUANTUM DOTS
QUENCHING
RELAXATION
SEMICONDUCTOR MATERIALS
TEMPERATURE RANGE 0065-0273 K
TUNNEL EFFECT
ZINC SULFIDES