The blue photoluminescence and nanostructure of Si and C clusters embedded in SiO2 matrices

Abstract

Carbon and silicon clustered films have been prepared by rf sputtering using a SiO2 target on which were placed lumps of C or Si, respectively, followed by annealing at 800°C or 600°C for 20–30 min in a N2 atmosphere. Information about the nanostructure of the films has been determined from photoluminescence (PL) and extended X-ray absorption fine structure (EXAFS). Blue PL from these films has been observed and reported for the first time, with peak wavelengths in the range from 420–500 nm, when excited by 260, 300 and 370 nm light produced by the tuneable synchrotron at DRAL Daresbury. The blue PL is visible to the naked eye when illuminated by ∼ 2.7 μW UV beam.