Magneto-optical properties of CdS nanoparticles embedded in phosphate glass

Cadmium sulphide nanoparticles were grown in phosphate glasses by a diffusion-controlled phase decomposition of over-saturated solid solution. The magneto-optical properties of the nanoparticles were examined by absorption, photoluminescence (PL) and optically detected magnetic resonance (ODMR) spectroscopy. The absorption and PL spectra presented a blue shift due to the quantum size effect. The ODMR measurements indicated that the luminescence of the materials is dominated by a broad band associated with a recombination of trapped electrons (e) and holes (h). The trapping sites include two subgroups located at the core and the surface. Those at the surface exhibit weak e–h exchange interaction and anisotropic broadening, due to variable e–h distances around the circumference of the nanoparticles. The trapped carriers in the core of the particles show weak crystallographic anisotropy and strong e–h exchange interaction.