Shedding light on organic transistors: insights could lead to brighter and cheaper displays

The first single-crystal organic transistor that can be switched on and off by light is giving physicists a unique peek into the way photons interact with organic semiconductors. For the makers of organic light-emitting diode (OLED) displays, which are used in everything from cameras to mobile phones, poor understanding of light's interactions with material properties becomes a problem. Today's amorphous or polycrystalline organic transistors are just not up to the job because bathing them in light generates unwanted photo-induced currents. In this paper, the author explains why the mobility drops as the temperature falls. In silicon transistors, the mobility increases as the material is cooled because electrons move more easily at low temperatures.