New type of thin film color image sensor

A new thin film color sensor array has been developed. In this device a single pixel consists of a combination of an amorphous silicon nipin detector and a crystalline operational amplifier. The carrier transport mechanisms of the diode under dark conditions as well as steady state opto electronic behavior of the nipin structure have been studied in theory and experiment in order to optimize the design of the image sensor. As a result, nipin structures with excellent dynamic range and linearity have been fabricated. Our study has also demonstrated that a three color detector can be obtained either by optimization of the design of the detector or by appropriate signal processing. The limitations arising from the design rules of the crystalline electronics for a single channel MOSFET process and their impact on readout performance and signal distortion are discussed. A novel two stage operational amplifier with optimized design and layout has been fabricated. Because of the superior performance of the amplifier and the diode this sensor is especially suitable for high sensitive color image processing applications.