Dual- $V_{rm th}$ Low-Voltage Solution Processed Organic Thin-Film Transistors With a Thick Polymer Dielectric Layer

摘要

Threshold voltage $(V_{rm th})$ control using different metal gates (aluminum and gold) was applied to realize dual- $V_{rm th}$ low-voltage solution processed organic thin film transistors (OTFTs). In the devices, the low-operation voltage was realized based on a channel engineering approach instead of using large gate dielectric capacitance, therefore, a relatively thick and low-dielectric constant polymer dielectric layer can be used. The devices present a mobility about 1.0 ${rm cm}^{2}/({rm V}cdot{rm s})$ , ON/OFF ratio of $10^{5}$ and small subthreshold swing of 100 mV/decade with the maximum processing temperature not exceeding 100 $^{circ}{rm C}$ . It was found that, even with a 400-nm thick polymer dielectric layer, since possible charge trapping effects was effectively suppressed by the crosslinking processes, well controlled $V_{rm th}$ was achieved. Both unipolar single- $V_{rm th}$ and dual- $V_{rm th}$ inverters were fabricated, clearly showing the influence of $V_{rm th}$ on the circuit operation and improved performance with the dual- $V_{rm th}$ OTFT technology.