Organic Light-Emitting Field-Effect Transistor with Channel Waveguide Structure

Organic field-effect transistors with channel waveguide structures were fabricated with thiophene/phenylene co-oligomer thin films. Top-contact source/drain electrodes of gold were deposited onto both side walls of the waveguide by the self-shadow masking vapor deposition technique leaving the co-oligomer channel of ${\sim}5$-\mbox{$\mu$m}-length intact. The device operated as a typical hole-accumulated unipolar transistor under negative gate biases. When alternating-current gate voltages were applied, the device showed light emission due to recombination of injected electrons with accumulated holes in the waveguide channel.