Printed dielectric-based organic diodes and transistors

Abstract

Inkjet and other forms of printing are now popular deposition techniques for the various layers in organic electronic devices, which are crucial for the development of large-scale, low-cost, and flexible electronics. Along with the ease of deposition, inkjet printing provides better control of the organic semiconductor–dielectric interface in field-effect transistors (FETs) and metal–insulator–semiconductor (MIS) diodes, compared to other deposition techniques. We compare the electrical characteristics of inkjet-printed and spincoated poly-4-vinyl phenol (PVP) dielectric layers in pentacene-based and 6, 13-bis(triisopropylsilylethynyl) (TIPS)-pentacene-based FETs and MIS structures. Printed PVP films provide a natural alignment for the growth of TIPS-pentacene, thus improving the interface. TIPS-pentacene on printed PVP shows an order of magnitude higher FET charge carrier mobility compared to TIPS-pentacene on spincoated PVP FETs. Capacitance–voltage and conductance–voltage investigations of the MIS structures yield a lower value for the interface trap density for the printed PVP TIPS-pentacene device compared to the spincoated PVP TIPS-pentacene diode. Thermally grown pentacene on printed and spincoated PVP shows similar performance in MIS and FET structures.