Giant phototransistor response in dithienyltetrathiafulvalene derivatives

Abstract

Thienyl-substituted tetrathiafulvalene (DTh-TTF, 1a) and a t-butyl derivative (1b) are prepared, and the remarkable photoresponse and memory effect in the transistors are investigated. Upon irradiation of light with a wavelength shorter than the absorption edge (535 nm), the threshold voltage of 1b shifts by as large as 57 V, and the drain current increases by 10³ times. The photo generated conducting state is maintained for several tens of minutes but erased by the application of a large negative gate voltage.