Optically and Electrically Driven Organic Thin Film Transistors with Diarylethene Photochromic Channel Layers

We achieved drain-current switching of diarylethene-channel field-effect transistors with light- and electric-field effects. The drain current was reversibly changed by alternating ultraviolet and visible light irradiation. Stress is placed on the fact that the on/off ratio realized by light irradiation was 1 x 10(2) (1 x 10(4)%) and this value is much larger than those in other photochromism-based transistors. These results indicate that the drain current was effectively controlled by light irradiation. Furthermore, the on and off states modulated by light were maintained without light irradiation even after 1 week, exhibiting that our transistor works as an optical memory. We clarified that the light-driven modulation can be attributed to the transformation in the pi-conjugation system accompanied by photoisomerization. These findings have the potential to attain high-performance optoelectrical organic devices including optical sensors, optical memory, and photoswitching transistors.