Photoinduced changes (Staebler-Wronski effect) in the photocurrent and dark current of a reverse-biased small-area Schottky barrier made from amorphous silicon are investigated. The well-known, small reductions in the photocurrent are contrasted with the large increases in the dark bias current. This behavior of the dark bias current is a new phenomenon and cannot be explained on the basis of a bulk mechanism. The indications are that even under high bias voltages recombination processes take place close to the interface and give rise to thermally reversible changes of the gap density-of-states. Special attention is paid to the bias voltage and wavelength dependence of the degradation effect. The results are discussed in qualitative terms.
ASJC Scopus subject areas
- Physics and Astronomy(all)