Berlin 2008 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 31: Poster II
HL 31.25: Poster
Tuesday, February 26, 2008, 16:30–19:00, Poster D
Micro-Raman studies of the formation of ternary and quaternary II-VI nanocrystals in borosilicate glass — •Yuriy Azhniuk1, Vasyl Lopushansky1, Yuriy Hutych1, Ivan Turok1, Larysa Prots1, Alexander Gomonnai1, and Dietrich R T Zahn2 — 1Institute of Electron Physics, Uzhhorod, Ukraine — 2Chemnitz University of Technology, Chemnitz, Germany
Diffusion-limited growth in a silicate glass is a well-elaborated technique for obtaining II-VI semiconductor nanocrystals (NCs). The dependence of NC size on the growth conditions (heat treatment duration and temperature) has been studied extensively. Much less investigated is the variation of the chemical composition of ternary and quaternary II-VI NCs with heat treatment parameters. This can effectively be performed using Raman scattering.
Here we present resonant micro-Raman studies for an extensive set of NCs of the ternary CdS1−xSex, Cd1−xZnSx, CdSe1−xTex and quaternary Cd1−yZnyS1−xSex systems grown in borosilicate glass by thermal treatment at 625 to 700oC. Measurements were performed using a Dilor XY 800 spectrometer and different Ar+ laser lines for excitation. For CdS1−xSex NCs the content of Se is shown to grow with the heat treatment duration and temperature. For zinc-containing ternary and quaternary NCs the Zn content increases with heat treatment duration and temperature up to 0.3 due to the migration of Zn atoms from the matrix to the NCs. Raman features observed at the initial stages of heat treatment as well as at elevated heat treatment temperatures are discussed in view of possible selenium cluster segregation.