Effects of varying light bias on an optically-addressed two-terminal multicolor photodetector

Multicolor photodetectors often require more than two terminals, making it very difficult to construct multicolor FPAs, due to the increased processing complexity. A novel approach is proposed to overcome this problem: an optically-addressed two-terminal multicolor photodetector. This two-terminal detector design is important for FPAs because it maximizes the fill factor and simplifies the necessary ROICs. This novel device concept is demonstrated using LEDs as the optical bias sources and a three-color detector. Varying light bias levels expose the effects of, luminescence coupling, optical leakage, and shunt leakage currents on the detector performance. The measured dark current, responsivity, and linear dynamic range of the detector reveal a tradeoff between low optical bias for minimal dark current and maximum responsivity and high optical bias for maximum dynamic range for optimal detector performance.