Accumulation and depletion layer thicknesses in organic field effect transistors

TL;DR

This paper introduces a method to measure the accumulation and depletion layer thicknesses in organic field effect transistors by in-situ conductivity measurements, providing insights into carrier distribution.

Contribution

A novel in-situ measurement technique for determining layer thicknesses and carrier distribution in organic FETs is presented.

Findings

Accumulation layer thickness in pentacene is 0.9 nm at VG=-15 V.

Depletion layer thickness in pentacene is 5 nm at VG=15 V.

Method allows continuous measurement of conductivity as a function of film thickness.

Abstract

We present a simple but powerful method to determine the thicknesses of the accumulation and depletion layers and the distribution curve of injected carriers in organic field effect transistors. The conductivity of organic semiconductors in thin film transistors was measured in-situ and continuously with a bottom contact configuration, as a function of film thickness at various gate voltages. Using this method, the thicknesses of the accumulation and depletion layers of pentacene were determined to be 0.9 nm (VG=-15 V) and 5 nm (VG=15 V).