High-current-density ITOx/NiOx thin-film diodes

Thin-film diodes 0.2-4x10(-5) cm(2) in size were fabricated on Al2O3-TiC ceramic substrates from junctions between p-type NiOx and n-type ITOx thin films sputter deposited at ambient temperature. These diodes show a room-temperature turn-on voltage of 0.3-0.5 V acid a dc forward current density exceeding 10(4) A/cm(2) at an applied voltage of similar or equal to 1.5V. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of these diodes call be described by an exponential dependence of I on the applied V and by a linear I/C-2 dependence on the reverse applied V, respectively, consistent with those predicted by the various models proposed for the mechanisms for charge-carrier transport in abrupt anisotype heterojunctions. The ideality factor at few-applied V (less than or equal to 0.3V), the junction built-in potential, and the carrier concentration deduced froln these I-V and C-V data are similar or equal to 1.5-2, 0.20-0.24V, and 1.90-1.97x10(18)/cm(3), respectively. (C) 1998 American Institute of Physics.