Multispectral Photonic Crystal Photo Sensor

A novel photo sensor pixel using a one-dimensional (1D) photonic crystal structure incorporating photoconductive layers has been realized. The fabricated device exploits mode discrimination to provide simultaneous multispectral photo sensing capability. Resonant cavity enhancement (RCE) design allows the use of very thin photoconductive layer to achieve dramatically suppressed shot noise, as well as high quantum efficiency. Low cost amorphous silicon is used to be photoconductive material and the simply fabrication process is completely CMOS-compatible. Detectivities as high as 2.6×1010 cmHz1/2W−1 and 2.0×1010 cmHz1/2W−1 at the two pre-selected wavelengths, 632nm and 728nm, were achieved, respectively.