CdSxSe1−x quantum dots studied through optical absorption, steady-state photoluminescence, and resonant Raman spectroscopies
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CdSxSe1−x nanoparticles or quantum dots (QDs) were grown in borosilicate glass by a two-step heat-treatment process from a melt-quenched color filter glass. We incorporate the results of optical absorption, steady-state photoluminescence (PL), and resonant Raman spectroscopies in the study of growth kinetics of CdSxSe1−x QDs. A modeling of PL spectra employing two Gaussian emission bands and a quantized-state effective mass model in the strong confinement regime reveals that (i) the average particle size ranges from 1.7 to 8.5 nm, (ii) the size dispersion narrows down to 0.22 nm for a single sample, and (iii) QDs form by diffusion-limited growth. We presume that size-dependent higher energy PL band close to the asymptotic absorption edge is due to surface-assisted electron-hole recombination since the difference between optical absorption and PL bands decreases from 239 to 122 meV with increasing average radius.
KeywordsSize Dispersion Exciton Peak Exciton Band High Energy Peak Energetic Position
This work is supported by Yıldız Technical University Research Project Coordination under project nos. 23-01-01-01 and 24-01-01-03 and partly by TUBITAK under the project no. TBAG-AY/378 (104T119). We thank M. Çulha for taking Raman spectra.
- 1.Ekimov AI, Onushchenko AA (1981) JETP Lett 34:345Google Scholar
- 2.Flytzanis C, Harbe F, Klein MC, Ricard D (1990) Optics in complex systems. SPIE, Bellingham, WAGoogle Scholar
- 5.Chan WCW, Maxwell DJ, Gao X, Bailey RE, Han M, Nie S (2002) Curr Opin Microbiol 13:40Google Scholar
- 9.Ekimov AI, Onushchenko AA (1982) Sov Phys Semicond 16:775Google Scholar