RF Sputtered gold-amorphous silicon Schottky-barrier diodes

Abstract

Gold Schottky-barrier diodes formed on reactively sputtered amorphous silicon thin films have been investigated. Device forward I–V characteristics are well modeled as a Schottky diode in series with a temperature activated series resistor. At 300 K, the forward current indicates a diode correction factor of 1.4 and a saturation current of 5.8 × 10–10 A/cm2. The metal-semiconductor barrier height is 0.93 eV. Capacitance versus frequency measurements indicate a depletion region thickness of 3000 A. In the depletion region, the mobility-lifetime products are estimated to be of the order of 5 × 10–11 cm2/V which is substantially less than the value of 10–7 cm2/V in the quasi-neutral region. It is suggested that deep gap states are responsible for this difference. Carrier recombination in the depletion region limits the photovoltaic performance. Copyright © 1982 by The Institute of Electrical and Electronics Engineers, Inc.