Temperature dependent excited state dynamics in dual emissive CdSe nano-tetrapods
| Autor: | Sucheta Banerjee, Anindya Datta, Rohit Srivastava, Ashutosh Gupta |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Photoluminescence
Materials science LIGHT-EMITTING-DIODES JUNCTION SOLAR-CELLS General Physics and Astronomy 02 engineering and technology ULTRAFAST CARRIER DYNAMICS 010402 general chemistry 01 natural sciences Molecular physics TRANSIENT ABSORPTION CORE-SHELL Ultrafast laser spectroscopy NANOPARTICLES Radiative transfer Physical and Theoretical Chemistry Wurtzite crystal structure CADMIUM SELENIDE NANOCRYSTALS OPTICAL-PROPERTIES CDTE Liquid nitrogen Nanosecond 021001 nanoscience & nanotechnology 0104 chemical sciences Excited state SEMICONDUCTOR QUANTUM DOTS 0210 nano-technology Ground state |
| Zdroj: | Physical Chemistry Chemical Physics. 20:4200-4207 |
| ISSN: | 1463-9084 1463-9076 |
| DOI: | 10.1039/c7cp06954e |
| Popis: | Time resolved spectroscopic investigation has been performed on nano-tetrapods, which are exotic nanocrystals with zinc blende type core structure and four arms with wurtzite structure. Dual emission is observed in these nanostructures. A band-edge emission occurs at 500-600 nm and a broad surface state emission occurs in the 600-900 nm region. The band-edge emission decays almost completely in a few ps, indicating the operation of an efficient trapping process. Incomplete recovery kinetics of ground state bleach from transient absorption experiments signifies the existence of a long-lived excited state. The lifetime of the surface state emission is in tens of nanoseconds. At liquid nitrogen temperature, surface state emission is enhanced to a greater degree than band edge emission, indicating suppression of various deactivation pathways at this temperature. Thus, an idea of excited state dynamics of these systems is developed, with a view of future tuning of photoluminescence properties by playing with the different radiative and nonradiative pathways involved. |
| Databáze: | OpenAIRE |
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