Improvement of the comprehensive properties of polymer templates via a novel dry blending method for fabricating OTFT electrodes

Abstract

Polymer template is widely used in the fabrication of organic thin-film transistor (OTFT) electrodes. However, the mechanical/thermal properties of the polymer template are generally poor owing to their low Young’s modulus (E) and high coefficient of thermal expansion (CTE), resulting in the formation of massive wrinkles and cracks on the OTFT electrodes, as well as the electrodes incomplete transfer, which seriously affects the fabrication of the electrodes. Here, a novel dry blending method is described in which SiO2 nanoparticles are filled into a grooved silicon template, followed by permeation of polydimethylsiloxane (PDMS) into the SiO2 nanoparticle gaps. The SiO2 nanoparticles in the groove are extracted by curing and peeling off PDMS, affording a PDMS/SiO2 composite template with a nanoparticle content of 83.8 wt% and good transparency. The composite template has a Young’s modulus of 16.58 MPa and a CTE of 96 ppm/°C, which constitutes an increase of 91.56 % and a reduction of 69.23 %, respectively, compared with the original PDMS template. Finally, the high performance OTFT electrodes were fabricated using the composite template with good comprehensive properties.