Effect of OFET based on P3HT:PVK Active Layer Blending on its Electrical Performance and $\text{NO}_{2}$ Gas Sensitivity

OFET has been widely used in gas sensor field because of its advantages of low cost and large area preparation. The OFETs of a single active layer are not highly responsive to gas, therefore this paper takes PVK and P3H<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$T$</tex> blends as active layers, and tests the electrical characteristics and gas sensitivity of OFET with different blending ratios. When the PVK: P3H<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$T$</tex> blend ratio is 50wt.%, the carrier mobility increases from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.0061\text{cm}^{2}/\text{Vs}$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.027\text{cm}^{2}/\text{Vs}$</tex> by 4.43 times, and the threshold voltage decreases from 29.46V to 23.01V. NO2 sensing performance at 20ppm was also tested. When the PVK: P3HT blend ratio is 100wt. %, OFET has a higher response of 209%, and the NO2 response of the blended device is 4.75 times higher than that of the unblended device.