Organic light-emitting transistors

We succeeded in observing electroluminescence (EL) of Tetraphenulpyrene (TPPy) as an active layer in an organic field-effect transitor (OFET). In particular, an OFET with a short channel of dSD<1.0 mu m demonstrated higher EL efficiency than one with a much longer channel (dSD<10 mu m). We observed a maximum EL quantum efficiency (nmax) of similar to 0.3% in the short-channel-length device at an applied source-drain voltage of Vd similar to 100 V and a gate voltage of Vg > -50 V. From the OFET characteristics, although the TPPy layer demonstrated typical p-type operation, the occurence of EL clearly indicated simultaneous hole and electron injection from the source and drain electronics, respectively under high Vd and Vg.