TIPS-pentacene:Polymer blend inverters with improved gain
Inverter circuits based on neat TIPS-pentacene and TIPS-pentacene: polystyrene blend organic field-effect transistors (OFETs) with external resistive load has been studied. Resistive loads of 28 ΜΩ, 40 ΜΩ, 68 ΜΩ and 108 ΜΩ were used to study the inverter transfer characteristics. Transfer characteristics of both types of inverters are improved with increasing load resistance. Inverter with a representative OFET with neat TIPS-pentacene shows a DC voltage gain of −6.9, swing of 40 V, and static power dissipation of 9.5 μW with load of 108 ΜΩ and 50 V power supply. Similarly, inverter with a representative TIPS-pentacene: polymer blend OFET shows a DC voltage gain of −8.7, swing of 44 V, and static power dissipation of 10.2 μW with the same load. For both neat TIPS-pentacene and TIPS-pentacene: polymer blend inverters, maximum DC gain and voltage swing are achieved with highest value of resistive load. However, switching thresholds near VDD/2 are obtained with moderate resistive loads.