SnO2 nanocrystals in SiO2:: A wide-band-gap quantum-dot system

Nanoclusters of crystalline SnO2 have been grown in glass, starting from tin-doped silica prepared by a sol-gel method. Based upon a particular choice of molecular precursors, nanocrystallites with a mean radius of about 1 nm and a quite narrow size dispersion were obtained, resulting in wide-band-gap (>4 eV) quantum dots (QDs). In this system, differently from other semiconductor-doped glasses, both the glassy host and the nanophase are oxides of IV-group elements. Owing to their thermochemical compatibility, the two phases give stable optical-grade glass ceramics with potential applications in photonics, opening up the field to technological employments of wide-band-gap QDs. (C) 2002 American Institute of Physics.