ac electrical properties and I‐V characteristics of MoO3 film under dc bias

摘要

The ac electrical properties and the I-V Δ characteristics of AuMoO3Au thin-film sandwiches were measured under dc voltage bias. The capacitance of the samples is a strong function of the temperature and dc voltage bias. It increases as much as a factor of 20 for a 2900-Å-thick sample as the temperature is increased; this variation is reduced with increasing voltage bias. At 325 °K the capacitance is a strong function of the dc voltage bias, decreasing from its zero-bias value by about 50% at V = 1.5 V. The voltage dependence of the capacitance decreases with decreasing temperature, and at T = 77 °K it is essentially voltage independent. The conductance is also observed to be strongly dependent on temperature and dc voltage bias. For V>~0.6  face=''roman''>V, it initially increases strongly with increasing temperature and reaches a maximum value at about 310 °K. With further increase in temperature, it decreases to a minimum value and then increases monotonically. For face=''roman''>V≳0.6  face=''roman''>V, the conductance increases monotonically with increasing temperature. The I-V characteristics under dc bias are essentially thickness independent for V>~0.6  face=''roman''>V and thickness dependent for V≳0.6  face=''roman''>V. All the results are interpreted in terms of a self-consistent model that incorporates Schottky barriers at the two metal-insulator interfaces and a conduction process that exhibits an electrode-limited to bulk-limited transition occurring at V ≅ 0.6 V.