Self-Assembled Photochromic Molecular Dipoles for High Performance Polymer Thin-Film Transistors

TL;DR

This paper presents a novel photochromic molecular dielectric structure enabling optical control and significant performance enhancement in polymer thin-film transistors, achieving high mobility and increased capacitance.

Contribution

It introduces a rationally designed photochromic nanodielectric with tunable polarization for high-performance, optically controllable polymer transistors, a new approach in flexible electronics.

Findings

Achieved p-type mobility exceeding 2 cm^2/(V.s)

Demonstrated a three-fold increase in capacitance

Observed a transport mechanism crossover with temperature

Abstract

The development of high-performance multifunctional polymer-based electronic circuits is a major step towards future flexible electronics. Here, we demonstrate a tunable approach to fabricate such devices based on rationally designed dielectric super-lattice structures with photochromic azo-benzene molecules. These nanodielectrics possessing ionic, molecular, and atomic polarization are utilized in polymer thin-film transistors (TFTs) to realize high performance electronics with p-type field-effect mobility exceeding 2 cm^2/(V.s). A crossover in the transport mechanism from electrostatic dipolar disorder to ionic-induced disorder is observed in the transistor characteristics over a range of temperatures. The facile supramolecular design allows the possibility to optically control the extent of molecular and ionic polarization in the ultra-thin nanodielectric. Thus, we demonstrate a three-fold increase in the capacitance from 0.1 uF/cm^2 to 0.34 uF/cm^2, which results in a 200% increase in TFT channel current.