MAGNETOOPTICAL PROPERTIES OF CDS NANOPARTICLES EMBEDDED IN PHOSPHATE-GLASS

Cadmium sulphide nanoparticles were grown in phosphate glasses by a di ffusion-controlled phase decomposition of over-saturated solid solutio n. The magneto-optical properties of the nanoparticles were examined b y absorption, photoluminescence (PL) and optically detected magnetic r esonance (ODMR) spectroscopy. The absorption and PL spectra presented a blue shift due to the quantum size effect. The ODMR measurements ind icated that the luminescence of the materials is dominated by a broad band associated with a recombination of trapped electrons (e) and hole s (h). The trapping sites include two subgroups located at the core an d the surface. Those at the surface exhibit weak e-h exchange interact ion and anisotropic broadening, due to variable e-h distances around t he circumference of the nanoparticles. The trapped carriers in the cor e of the particles show weak crystallographic anisotropy and strong e- h exchange interaction. (C) 1998 Elsevier Science B.V. All rights rese rved.