Improved performance uniformity of inkjet printed n-channel organic field-effect transistors and complementary inverters

Abstract

In the present study, we demonstrate inkjet-printed n-type organic field-effect transistors (OFETs) and their complementary inverters with high performance uniformity, using soluble N, N′-bis( n-octyl)-(1,7&1,6)-dicyanoperylene-3,4:9,10-bis(dicarboximide) (PDI8-CN 2). The device performance and uniformity were improved by ink-jet printing a PDI8-CN 2 solution onto a heated substrate (60 °C). The printed features, which were discontinuous crystalline films at RT, were uniform films when the substrate temperature was increased to 60 °C. Optimized n-channel PDI8-CN 2 FETs showed a high field-effect mobility of 0.05–0.06 cm 2/Vs, a high on/off ratio of ∼10 6, and a high uniformity that was within 10% with a bottom-gate/bottom-contact device configuration. Inkjet-printed organic complementary inverters were constructed by direct inkjet-printing of n-channel (PDI8-CN 2) and p-channel (6,13-bis(triisopropyl-silylethynyl)-pentacene or poly(3-hexylthiophene)) organic semiconductors onto silicon dioxide gate dielectrics. The inkjet-printed organic complementary inverters exhibited a high voltage gain of more than 15 and small standard deviation of inverting voltage and gain of ±0.95 V and ±0.56, respectively, for measuring 12 samples from four difference batches.