The optical properties of glasses containing a small amount of thermally developed CdSexS1minus;xmicrocrystalline phase are studied with emphasis on quantum confinement effects exhibited at small crystallite size. Optical absorption, photoluminescence, xhyphen;ray diffraction, and transmission electron microscopy are used to examine microcrystallites as a function of composition and development. Results are presented for a series of commercially available CorningRfilter glasses with a selenium mole fraction in the range 0.28le;xle;0.74, as well as for several experimental glasses in which the average microcrystallite diameters range from 30 to 80 Aring;. Optical effects observed in the experimental glasses that are due to electron and hole confinement arenotpresent in the filter glasses considered; variations in optical properties of the filters are due to changes in stoichiometry of the CdSexS1minus;xmixed anion system. A brief discussion of other microcrystalline phases in glass is also presented. These microcrystallites show roomhyphen;temperature optical absorption structure analogous to bulk crystal excitons; the temperature dependence of this structure is contrasted with that resulting from quantum confinement in CdSexS1minus;xglasses.
展开▼
