Electroluminescence of 2,4-bis(4-(2′-thiophene-yl)phenyl)thiophene in organic light-emitting field-effect transistors -: art. no. 093505

We succeeded in observing electroluminescence (EL) of 2,4-bis(4-(2'-thiophene-yl)phenyl)thiophene (TPTPT) as an active layer in an organic field-effect transistor (OFET). In particular, an OFET with a short channel of d(SD)=0.8 mu m demonstrated higher EL efficiency than one with a much longer channel (d(SD)=9.8 mu m). We observed a maximum EL quantum efficiency (eta(max)) of 6.4 x 10(-3) % in the short-channel-length device at an applied source-drain voltage of V-d=-100 V and a gate voltage of V-g=-40 V. 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 V-d and V-g. (C) 2005 American Institute of Physics.