Electro-optic measurement of carrier mobility in an organic thin-film transistor

TL;DR

This paper demonstrates an electro-optic method to measure the position-dependent infrared absorption and carrier mobility in an organic thin-film transistor using time-resolved charge accumulation techniques.

Contribution

It introduces a novel electro-optic approach for measuring carrier mobility in organic transistors through infrared absorption analysis.

Findings

Successful measurement of hole mobility in an organic semiconductor

Time-resolved charge accumulation correlates with applied voltage frequency

Method provides spatially resolved mobility data

Abstract

We have used an electro-optic technique to measure the position-dependent infrared absorption of holes injected into a thin crystal of the organic semiconductor, 6,13-bis(triisopropylsilylethynyl)-pentacene incorporated in a field-effect transistor. By applying square-wave voltages of variable frequency to the gate or drain, one can measure the time it takes for charges to accumulate on the surface, and therefore determine their mobility.