High-performance ultra-low-voltage organic field-effect transistors based on anodized TiOx dielectric and solution-sheared organic single crystals

Abstract

Organic field-effect transistors (OFETs) are promising building blocks for wearable electronics applications due to their low processing temperature and mechanical flexibility. The OFETs for such applications are expected to operate at a low voltage that is within the range of portable batteries. An anodized TiO_x dielectric is a promising device for reducing power consumption by decreasing the gate-source voltage of OFETs, but this often leads to poor OFET performance due to the large surface roughness. This work presents an optimal solution for achieving ultra-low-voltage (at 1 V) device operation using an anodized TiO_x/PS hybrid dielectric combined with a solution-sheared organic single-crystal thin film. The anodized TiO_x produces a high unit-area capacitance of up to 2500 nF cm⁻² with good uniformity, and the organic single-crystal thin film achieves a high carrier mobility of 4.5 cm² V⁻¹ s⁻¹ and a low threshold voltage of 0.13 V. The use of a polystyrene layer and TiO_x as the gate dielectric demonstrates the systematic optimization of OFETs and their great potential in high-performance, ultra-low-voltage organic circuit applications.