New Organic Phototransistor With Bias-Modulated Photosensitivity and Bias-Enhanced Memory Effect

A simple and effective method to adjust organic thin-film transistor photosensitivity was proposed. First, the full suppression of light-induced threshold-voltage shift was successfully demonstrated by applying negative gate bias during illumination. Then, the light-induced threshold-voltage shift that was modulated from 0 to 13.5 V was achieved by changing the drain and source bias from +15 to -15 V. Plausible mechanisms were proposed and verified. After light removal, the memory ability of the threshold-voltage shift was also greatly enhanced by the bias effect. The results demonstrate a sensitive organic phototransistor with memory ability by adjusting suitable bias conditions.