On/Off Ratio of a Pentacene Field-Effect Transistor with a Discontinuous MoO₃ Layer

Abstract

Improvement of the on/off ratio in organic field-effect transistors through the use of pentacene and molybdenum trioxide (MoO₃) layers was attempted via the preparation of a discontinuous MoO₃ layer using a mesh mask. We prepared three types of devices. Device A had a conventional top-contact structure with an n-type Si wafer and a 200-nm-thick SiO₂ film onto which we deposited a 70-nm-thick pentacene film and a 30-nm-thick layer of Au top electrodes. Devices B and C had a similar structure to device A but received a continuous and a discontinuous MoO₃ layer, respectively. The off current in Device B was remarkably high; in contrast, the off current in Device C was reduced and dependent on the separation of the MoO₃ layer. It was deduced that the high resistance of the area without MoO₃ contributed to the reduced off current.