Detecting 100 fW cm -2 Light with Trapped Electron Gated Organic Phototransistors.

Ultraweak light detection with solid-state and cooling-free photodetectors is important for both fundamental research and practical applications. A general phototransistor architecture for detecting ultraviolet-visible light down to 100 fW cm-2 at room temperature is demonstrated. The exceptional sensitivity stems from an amplification process triggered by incident light. A responsivity of ≈107 A W-1 is achieved.