Dresden 2009 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 48: Poster 2
HL 48.47: Poster
Donnerstag, 26. März 2009, 15:00–17:30, P2
Formation of molecular clusters of selenium as an alternative to precipitation of CdSe nanoparticles in a borosilicate glass — •Yuriy Azhniuk1, Vasyl Lopushansky1, Yuriy Hutych1, Alexander Gomonnai1, and Dietrich R. T. Zahn2 — 1Institute of Electron Physics, Ukr. Nat. Acad. Sci., Uzhhorod, Ukraine — 2Chemnitz University of Technology, Semiconductor Physics, D-09107 Chemnitz, Germany
Solid-state precipitation in a borosilicate glass is a well-elaborated technique for obtaining II-VI semiconductor nanocrystals. The obtained nanocrystal size depends on the growth conditions (heat treatment temperature and duration). Here we present Raman evidence for an alternative process, precipitation of molecular clusters of selenium, which is also possible at certain growth conditions.
Decoloured CdSe-doped borosilicate glass samples were subjected to thermal treatment at 625 to 700oC during 2 to 12 h. Resonant micro-Raman measurements were performed using a Dilor XY 800 spectrometer and different Ar+ laser lines for excitation. Besides the CdSe LO and 2LO phonon bands, the Raman spectra of the samples obtained at thermal treatment duration and temperature beyond the range, most suitable for the formation of CdSe nanocrystals, contained pronounced features at 323 and 646 cm−1. Based on their frequency positions, widths, intensities, and resonant behaviour, these features are attributed to Se2 clusters being formed in the glass during the thermal treatment.