Cathodoluminescence of ZnSiO(x) nanocomposite films prepared on Si substrates

Abstract

Optoelectronic materials compatible with silicon substrates are important from the viewpoint of practical applications for silicon photonics. ZnO nanocrystals were fabricated directly on Si substrates by tuning both of the composition and postannealing conditions of ZnSiO(x) composite films deposited by sputtering Si and ZnO targets simultaneously. The high-resolution TEM analysis showed that ZnSiO(x) nanocomposite film containing ZnO nanocrystals could be obtained by postannealing the ZnSiO(x) film with Zn/Si ratio = similar to 1.6 at 700 degrees C. In this film, ZnO nanocrystals with a size of similar to 5 nm, which could be identified as ZnO from electron diffraction pattern, were densely distributed in the amorphous matrix. This film exhibited a stronger and broader cathodoluminescence emission ranging from 350 nm to 550 ran compared to that of ZnO film fabricated with the same deposition conditions. These results lead to a practical application of ZnO nanocrystals to optoelectronic devices using Si substrates. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA. Weinheim