Frequency behavior and the Mott-Schottky analysis in poly(3-hexyl thiophene) metal-insulator-semiconductor diodes

Metal-insulator-semiconductor diodes with poly(3-hexyl thiophene) as the se miconductor were characterized with impedance spectroscopy as a function of bias, frequency, and temperature. We show that the standard Mott-Schottky analysis gives unrealistic values for the dopant density in the semiconduct or. From modeling of the data, we find that this is caused by the relaxatio n time of the semiconductor, which increases rapidly with decreasing temper ature due to the thermally activated conductivity of the poly(3-hexyl thiop hene). (C) 2001 American Institute of Physics.