Observation of two modes of current transport through phosphorus-doped amorphous hydrogenated silicon Schottky barriers

The influence of phosphorus impurities in the active layer of amorphous hydrogenated silicon Schottky barriers is investigated by experimentally studying the current-voltage characteristics of the structure and the physical and electronic properties of the material. With increasing phosphorus concentration excess diode currents develop. Numerical analysis shows that (1) these currents are due to hopping within an impurity band produced by the impurities and (2) a two-channel conduction mechanism is in quantitative agreement with the data.