Effects of TIPS-Pentacene/PS Blends on OFETs Performance and $\text{NO}_{2}$ Gas Responsiveness

OFET devices prepared by solution methods have the advantages of high integration, low cost, large area preparation and ductility, and are widely used in the field of gas sensors. In this paper, the effects of the small molecule semiconductor TIPS-Pentacene and the insulating polymer PS blends as the active layer on the electrical properties and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{NO}_{2}$</tex> gas responsiveness of the device at various blending ratios were studied. When the PS blending ratio is 20wt.%, the mobility of the device is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.12 \text{cm}^{2} \mathrm{V}^{-1} \mathrm{s}^{-1}$</tex>, which is about 3 times higher than that of the unblended device. When the PS blend ratio is 40wt.%, the device has an optimal gas response of 181%(<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{V}_{\mathrm{G}}=-80 \mathrm{V}$</tex>), which is 4.8 times higher than that without blending, and the maximum response is 838% at the grid voltage of 0V, which is further improved by 4.6 times. It was found that phase separation occurred in the TIPS-Pentacene/PS blend film, and the addition of PS delayed the evaporation of the organic solvent, improved the crystalline structure of TIPS-Pentacene, and was conducive to charge transfer and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{NO}_{2}$</tex> gas sensitivity of OFET devices.