A study was made of the photoluminescence properties of Si-rich silica. Film samples which had been grown, using plasma-enhanced chemical vapor deposition, under a range of growth conditions were annealed under Ar at various temperatures. Photoluminescence spectra were measured for each film at room temperature and at cryogenic temperatures. It was found that the photoluminescence spectra exhibited 2 bands. Fourier transform infra-red and electron spin resonance spectroscopy were used to investigate bonding and defect states within the films. It was noted that the resultant data strongly suggested the existence of 2 luminescence mechanisms which exhibited differing dependences upon the growth and post-processing conditions. These mechanisms were suggested to be a defect luminescence that was associated with O vacancies, and the radiative recombination of electron-hole pairs that were confined within nm-sized so-called Si quantum confinement clusters.

A.J.Kenyon, P.F.Trwoga, C.W.Pitt, G.Rehm: Journal of Applied Physics, 1996, 79[12], 9291-300