Light emission from a polymer transistor

We report on light emission from a polymeric transistor that utilizes interdigitated source and drain electrodes with channel length of 5 μm in a bottom gate configuration based on a ${\mathrm{Si/SiO}}_2$ substrate. The polymer investigated is poly[9,9-di(ethylhexyl)fluorene] deposited by spin coating from chloroform solution to achieve an active layer thickness of 40 nm. Light emission occurs above drain source voltages of −60 V and the light intensity can be controlled by the gate voltage. Emission occurs close to the drain electrode as determined by optical microscopy. The transistor operates in hole accumulation mode without saturation of the output characteristics.