Noise in porous silicon structures in air and in conditions of gas adsorption

Low-frequency noise, in the range 1–500 Hz, is measured at room temperature in samples of Au/PS/SCS/Al structure with a layer of porous silicon. Numerical values of the Hooge parameter α H are estimated and the dependence of α H on the composition of the gaseous environment, where the sample is placed, is determined. Possible reasons of observed high values of α H for the samples in air and of the increase in α H in conditions of gas adsorption are discussed. Introducing of carbon oxide in air changes the shape of spectrum.