Alkylated silicon nanocrystals: Electronic and optical characterization and their potential applications

Alkylated Si nanocrystals could find applications as fluorescent tracers in biology, in optoelectronics and in floating gate devices. As a consequence, their structure and composition will have a critical bearing on the performance of any future nanocrystal-based device and so reliable chemical and structural characterization is essential. In this work we present an optical and atomic force microscopy study of Si nanocrystals deposited on glass and n-type Si (111) surfaces by evaporation of passivated silicon nanocrystals which show that controlled deposition of the macroscopic quantities needed for thin film formation is readily achieved. UV/Visible emission from these films, excited by 140 eV photons, was measured and shows a clear vibrational progression - up to six vibrational bands are visible at room temperature.