Facile Direct Printing of DPP-Based Polymers for Organic Field-Effect Transistors and Logic Gates

Polymer semiconductors having solubility in organic solvents can enable facile, low-cost, and large-area solution processes to fabricate electronic devices with various applications. However, it has been a challenge to build complicated circuits by using them due to device-to-device variation. In this study, we designed a diketopyrrolopyrrole (DPP)-based polymer with long and branched alkyl side chains to improve the solubility of DPP polymers. While the long and branched side chains are introduced to the DPP moieties for improved solubility, the far branching point in the side chains was expected to prevent severe steric hindrance of the long side chains and to allow DPP moieties to have π-π interactions and form crystalline structures. To examine the feasibility of using P29DPP-TT as a semiconductor in integrated electronic systems, the electrohydrodynamic (EHD) jet printing technique was used in for local area patterning. The organic field-effect transistors (OFETs) incorporating EHD-printed P29DPP-TT yield promising field-effect mobility (μ_FET) of 0.55 cm² V^-1 s^-1. Complementary inverters and NAND/NOR logic gates were also realized by fabricating OFETs with line-printed P29DPP-TT and polymer gate dielectrics. It indicates that P29DPP-TT with excellent solubility can be applied to solution-processed integrated electronic devices.