Filter-less color sensor in standard CMOS technology

An integrated color detector is presented, which is implemented in a standard 130 nm CMOS technology without process modification or additional optical components like color filters. The proposed structure consists of vertically and laterally arranged photodiodes, providing color separation based on lateral carrier diffusion and wavelength-dependent absorption-depth. Three independent detector output signals with optimized spectral responsivities allows a discrimination between red, green and blue light spectral components. Linear transformation can be used to realize standardized colorimetric R, G, B or X, Y, Z color space responses. The color detector is therefore a low cost alternative solution for various color sensing applications.