High-performance low-voltage tetracene phototransistors with polymer/AlOx bilayer dielectric

Abstract

We report on the tetracene-based photo thin-film transistors (photo-TFTs) which adopt thin poly-4-vinylphenol (PVP)/aluminum oxide (AlOx) bilayer and semitransparent NiOx for a gate dielectric and source/drain (S/D) electrode, respectively. Quite a large capacitance of 31 nF/cm(2) was effectively achieved from the thin polymer/high-k oxide dielectric bilayer that also showed a high dielectric strength of similar to 4 MV/cm. Our tetracene-based TFTs exhibited quite a good field effect mobility (similar to 0.23 cm(2)/V s) and a high on/off current ratio of similar to 10(5), while operating at a voltage less than -8 V. The tetracene-TFTs demonstrated good static photoresponses to green (540 nm), blue (450 nm), and ultraviolet (364 nm) illuminations under the low voltage. (c) 2006 The Electrochemical Society.