Blue light emission from silicon surfaces prepared by spark-erosion and related techniques

Abstract

We have investigated the photoluminescence (PL) of silicon surfaces treated by spark-erosion and related techniques as a function of gas composition and pressure. PL emission in the wavelength range of 400–550 nm and with decay times ≤5 ns has been observed. PL quantum efficiencies comparable to that of standard wet chemically prepared porous silicon are obtained. We have never found significant PL emission in the red spectral range. Our dry plasma techniques for the preparation of luminescent silicon surfaces are a promising alternative to the common anodizing process in hydrofluoric solutions.