Tunable Multispectral Color Sensor with Plasmonic Reflector

Abstract

Vertically integrated color sensors with plasmonic reflectors are realized. The complete color information is detected at each color pixel of the sensor array without using optical filters. The spectral responsivity of the sensor is tuned by the applied electric bias and the design of the plasmonic reflector. By introducing an interlayer between the lossy metal back reflector and the sensor, the reflectivity can be modified over a wide spectral range. The detection principle is demonstrated for a silicon thin film detector prepared on a textured silver back reflector. The sensor can be used for RGB color detection replacing conventional color sensors with optical filters. Combining detectors with different spectral reflectivity of the back reflector allows for the realization of multispectral color sensors covering the visible and the near-infrared spectral range.