Flicker noise in hydrogenated amorphous-silicon Schottky diodes

Abstract

Noise measurements have been performed on a-Si: H Schottky diodes with Au and Pt metal contacts. The noise was found to exhibit 1/f ⁿ behaviour with 0.7 < n < 1.3. The theory of flicker noise in intrinsic a-Si:H is further developed for Schottky diodes. The dependence of the noise on temperature and mean d.c. current is explained on the basis of this theory. It is shown that the measurements provide a means of calculating the density and distribution of the gap states. The results are found to be in good agreement with other techniques. They also suggest the presence of a peak in the gap-state density. around 0·4 eV below E_c .