Pulsed laser processing of poly(3,3‴-didodecyl quarter thiophene) semiconductor for organic thin film transistors

Abstract

We report on the growth of thin solid layers of poly(3,3‴ didodecyl quater thiophene) (PQT-12) by matrix-assisted pulsed laser evaporation (MAPLE), on silicon and quartz substrates. The effects of PQT-12 solubilization in toluene, anisole, 1,2-dichlorobenzene, and a mixture of chlorobenzene and 1,2-dichlorobenzene, are discussed with respect to the MAPLE technique. Different film thicknesses have been grown, and their morphology and optical properties are presented. Thermal analysis studies have been realized to understand and explain the laser-induced photo-thermal effects on the organic semiconductor. Subsequently, micrometric-sized pixels of PQT-12 have been printed by laser-induced forward transfer (LIFT), with the goal to fabricate organic thin-film transistors (OTFT) devices. The influence of the donor films thickness and morphology, in LIFT experiments, is discussed. Electrical characterizations supplement this study, the resulting printed transistors are fully functional and provide field-effect mobility up to 5×10−3cm2·V−1·s−1 together with current modulation of 106.