Tunable photodetectors based on amorphous Si/SiC heterostructures

We describe a novel family of two-color photodetectors based on p-i-n-i-p heterostructures in hydrogenated amorphous Si/SiC. The devices operate as bias-controlled light detectors with enhanced absorption in either the blue or the red regions. Compared to other two-color sensors based on amorphous Si/SiC n-i-p-i-n structures, they exhibit sharper wavelength selection and higher rejection ratios with excellent quantum efficiencies: full width at half maximum (FWHM) less than 130 mm, suppression up to 27 dB, and peak responsivity of about 150 mA/W are reported for both the blue and the red window. Simulation of the photoresponse of the device under steady-state and time-dependent voltage bias and under continuous illumination is also presented.<
>