High performance low voltage organic field effect transistors on plastic substrate for amplifier circuits

Abstract

The high performance air stable organic semiconductor small molecule dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT) was chosen as active layer for field effect transistors built to realize flexible amplifier circuits. Initial device on rigid Si/SiO 2 substrate showed appreciable performance with hysteresis-free characteristics. A number of approaches were applied to simplify the process, improve device performance and decrease the operating voltage: they include an oxide interfacial layer to decrease contact resistance; a polymer passivation layer to optimize semiconductor/dielectric interface and an anodized high-k oxide as dielectric layer for low voltage operation. The devices fabricated on plastic substrate yielded excellent electrical characteristics, showing mobility of 1.6 cm 2 /Vs, lack of hysteresis, operation below 5 V and on/off current ratio above 10 5. An OFET model based on variable ranging hopping theory was used to extract the relevant parameters from the transfer and output characteristics, which enabled us to simulate our devices achieving reasonable agreement with the measurements

On the Working Mechanisms of Solid‐State Double‐Layer‐Dielectric‐Based Organic Field‐Effect Transistors and Their Implication for Sensors

“…Today, the major application for FETs is found in digital logic, which requires fast and low power switching of such devices . Second, due to high input and low output impedance, FETs are also successfully used in amplifiers . Another emerging application of such devices, i.e., FET‐based sensors, is gaining more and more attention as reflected in increased number of publications …”

Gate bias system for OTFT electrical characterisation and low‐frequency noise measurements

“…Introduction: During the past few years, there has been an increasing interest in the investigation of passive and active devices capable of enabling the realisation of fully functional electronic systems on plastic substrates. One of the most important goal that is being pursued is the realisation of organic thin film transistors (OTFTs) with sufficiently large intrinsic gain and low noise (LN) to be used for the realisation of the basic building blocks of both analogue and digital circuits [1]. Noise measurements, and low-frequency noise measurements in particular, have proven among the most sensitive tool for investigating the conduction properties and the reliability of electron devices.…”