Photo Photo- and cathodoluminescence from SiO SiO2 films containing Ge Ge+ nanocrystals formed at nnealing under high hydrostatic pressure

摘要

In this paper the photoluminescence (PL) andrncathodoluminescence (CL) from Ge Ge-implanted SiO SiO2 films annealed atrnlow and hig high hydrostatic pressures have been investigated. It was foundrnh that a band at 390 nm wavelength related to the recombination on defectsrnin the SiO SiO2 matrix dominates in the PL spectra of the samples annealed atrnatmospheric pressure, while a band at 515 nm dom dominates in the spectra ifrninates the anneal was done at a pressure of 12 kbar. The position of the latterrnband is close to the band gap of Ge nanocrystals as estimated in thernframe of a model that takes into account the polarization interaction of anrnelectron and a hole with the surface of nanocrystals. In the CL spectra ofrnthe samples annealed at a high pressure the green PL band is not seen.rnThe difference between the PL and CL spectra is attributed to thernpresence of nonradiative recombination channels in the Si SiO2 matrix.