Electroluminescence of 2,4-bis(4-(2′-thiophene-yl)phenyl)thiophene in organic light-emitting field-effect transistors

Abstract

We succeeded in observing electroluminescence (EL) of 2,4-bis(4-(2′-thiophene-yl)phenyl)thio-phene (TPTPT) as an active layer in an organic field-effect transistor (OFET). In particular, an OFET with a short channel of dSD=0.8μm demonstrated higher EL efficiency than one with a much longer channel (dSD=9.8μm). We observed a maximum EL quantum efficiency (ηmax) of 6.4×10−3% in the short-channel-length device at an applied source-drain voltage of Vd=−100V and a gate voltage of Vg=−40V. From the OFET characteristics, although the TPTPT layer demonstrated typical p-type operation, the occurrence of EL clearly indicated simultaneous hole and electron injection from the source and drain electronics, respectively, under high Vd and Vg.