The electrical characterization of surfaces, interfaces and contacts to a-Si:H

The present work shows how transient photoconductivity can be used to characterize surfaces, interfaces, and contacts to hydrogenated amorphous silicon (a-Si:H). At a silicon nitride/a-Si:H interface an electron accumulation layer is found, whereas the native oxide induces a depletion layer. The accumulation is much greater when the nitride is deposited on top of the a-Si:H, rather than vice versa. The injection properties of n+ contacts are also investigated, and a study is made of the conditions under which these are partially or completely depleted, thereby affecting the carrier injection.