Hydrogenated amorphous silicon Schottky barriers diodes

Large-area (7-16 sq mm) Pt-Schottky barriers are realized on glow discharge undoped hydrogenated amorphous silicon prepared at three different substrate temperatures: 350, 400, and 450 C. A complete electrical characterization of the diodes is performed. From the I(V) characteristics versus temperatures, the barrier height and the bulk distance of the Fermi level to the conduction band are deduced. The saturation of the low frequency capacitance, at zero bias, above 150 C yields the density of states in the midgap and their electron capture cross section. Low flux (approximately 3 x 10 to the 13th/sq cm-s) spectral response of the diode makes it possible to deduce the collection length of photo-generated carriers and consequently the hole drift mobility-mean life-time product.