High recovery NO2 sensors of α-6T organic thin film transistors based on interface inducing growth

Abstract

In order to achieve high recovery for low concentration NO2 gas detection, the α-6T OTFT gas sensors were fabricated by inducing growth method. The effect of interface inducing layer and active layer thickness on the sensor performance was studied. It was found that the p-6P inducing layer improved the surface properties of SiO2 substrates and the α-6T films were manipulated to favorable film formation on p-6P interface layer. The α-6T crystal grains can be fused well and the large-area continuous crystal films were obtained. By the thickness modulation of α-6T active films, the sensors can achieve the detection to the low concentration of 1 ppm to NO2 gas and exhibit the rapid recovery of 28 s. And the sensitivity was as high as 998% / ppm and the responsivity was up to 2645% for 1 ppm NO2 gas. The formation of ultra-thin films on surface substrates is an effective method, which can induce the growth of organic semiconductor films and obtain the high-property devices.