Depletion width measurement in an organic Schottky contact using a metal-semiconductor field-effect transistor

Although the capacitance measurement is a common method to obtain the depletion width in a Schottky contact, the method is challenging in an organic Schottky junction since the capacitance is a combination of the capacitances associated with the trapped charges, bulk semiconductor, and the depletion region. The authors have implemented a metal-semiconductor field-effect transistor structure in order to estimate the depletion width in an organic Schottky contact. In the transistor the depletion width is calculated from the drain current at a small drain-source voltage. The result indicates a nonquadratic relation between the voltage and the depletion width.