Colour detection using a buried double p - n junction structure implemented in the CMOS process

The authors present a novel technique for monochromatic colour detection. By using a buried double p-n junction (BDJ) structure, wavelength-dependent photocurrents I1 and I2 can be measured. And the incident light wavelength can be identified from the ratio I2/I1. The device operation was verified with a test circuit implemented in CMOS process.