Towards low-voltage organic thin film transistors (OTFTs) with solution-processed high-<em>k</em> dielectric and interface engineering

Abstract

Although impressive progress has been made in improving the performance of organic thin film transistors (OTFTs), the high operation voltage resulting from the low gate capacitance density of traditional SiO2 remains a severe limitation that hinders OTFTs'development in practical applications. In this regard, developing new materials with high-k characteristics at low cost is of great scientific and technological importance in the area of both academia and industry. Here, we introduce a simple solution-based technique to fabricate high-k metal oxide dielectric system (ATO) at low-temperature, which can be used effectively to realize low-voltage operation of OTFTs. On the other hand, it is well known that the properties of the dielectric/semiconductor and electrode/semiconductor interfaces are crucial in controlling the electrical properties of OTFTs. By optimizing the above two interfaces with octadecylphosphonic acid (ODPA) self-assembled monolayer (SAM) and properly modified low-cost Cu, obviously improved device performance is attained in our low-voltage OTFTs. Further more, organic electronic devices on flexible substrates have attracted much attention due to their low-cost, rollability, large-area processability, and so on. Basing on the above results, outstanding electrical performance is achieved in flexible devices. Our studies demonstrate an effective way to realize low-voltage, high-performance OTFTs at low-cost.

Keywords

• high-<i>k</i>
• solution processed
• low voltage
• OTFTs
• interface engineering
• flexible