Controlling the photoluminescence spectra of porous nc-Si–SiOx structures by vapor treatment

Abstract

The effect of HF and H₂O₂ vapor treatment on the spectral composition and intensity of photoluminescence (PL) in porous oblique deposited nc-Si–SiOx structures have been studied using FTIR, electron-spin resonance (EPR) and PL measurements. As a result of HF vapor treatment, considerable PL intensity growth and blueshift of PL peak position are observed. It is suggested that the evolution of the PL spectra in HF vapor-treated samples can be attributed to selective-etching-induced decrease in Si nanoparticle dimensions and to passivation of Si dangling bonds (that are nonradiative recombination trap states) by hydrogen and oxygen. Additional treatment in H₂O₂ vapor results in additional nc-Si surface oxidation and reduction of nc-Si size. The possibility to control the PL characteristics (peak position and intensity) of the porous nc-Si–SiOx structures in a wide range by above treatments is shown.