Periodic arrays of organic crystals on polymer gate dielectric for low-voltage field-effect transistors and complementary inverter

Abstract

Periodic arrays of highly oriented 7,7,8,8-tetracyanoquinodimethane (TCNQ) crystals, directly grown on a polymeric gate dielectric through a solution process, are used for the fabrication of a low-voltage organic field-effect transistor (OFET). Consequently, an organic complementary inverter using the TCNQ periodic array (n-channel) and pentacene (p-channel) is also reported. The TCNQ-based n-channel OFET exhibited very stable field-effect characteristics with low operational (2 V) and threshold voltages (<0.5 V). The highest field-effect carrier mobility in the saturation region was found to be 0.03 cm2 V−1 s−1. Furthermore, the organic complementary inverter showed good response characteristics in the low-voltage regime. The swing range of VOUT is same as VDD, ensuring “zero” static power consumption in the digital logic circuit. For the inverter with VDD = 2 V, the noise margin for low and high voltages are 1.0 V and 0.3 V, respectively. The logic threshold (VIN = VOUT) is 1.3 V and the maximum gain (−dVOUT/dVIN) of 4 is obtained at VIN = 1.3 V.