Effect of TIPS-Pentacene:Polystyrene Blend Ratio on Electrical Performance and Stability of Solution Processed Organic Field-Effect Transistors

We report the effect of varying the semiconductor:polymer blend ratio on the electrical performance and bias-stress stability of the organic field effect transistors (OFETs) with TIPS-Pentacene and polystyrene as semiconductor and polymer combination. Device performance was found to improve with increasing polymer content in the solution. Devices with 1:3 TIPS-Pentacene:polystyrene blend outperformed the other counterparts with high performance, and demonstrated least performance variation with regular 100 transfer measurement cycles. In addition, 1:3 blend devices have shown the least normalized drain current decay of $\sim$ 8.5 % with the bias stress condition of VDS = VGS = -30 V for 2 h, as compared to the 1:1, 3:1 and neat devices with the decay of 15 %, 37 % and 71 % respectively. Additionally, a better recovery of electrical characteristics was observed in blend devices with larger polymer fractions from the deteriorating effects of gate bias stress.