Pulsed operation of InGaZnO TFTs for VOC sensing applications

In this work, the detection of volatile organic compounds (VOCs) using amorphous indium gallium zinc oxide (a-InGaZnO) thin film transistors (TFTs) is explored. Pulsemode biasing to improve the long-term stability of these TFTs when exposed to the environment and under bias stress is proposed. Coated with a non-conducting polyepichlorohydrin (PECH) film, the TFTs under constant voltage bias exhibit a reversible response to varying ethanol concentrations in the gas phase. Furthermore, by lowering the duty cycle (δ) using bias pulses, the drain current decay under voltage bias can be reduced, thus extending the device´s operational lifetime.