UV-Enhanced a-Si:H Metal–Semiconductor–Metal Photodetector

Planar metal-semiconductor-metal (MSM) photodetectors with very thin hydrogenated amorphous silicon (a-Si) films were fabricated for the detection of ultraviolet (UV) radiation. Since DNA and proteins strongly absorb UV radiation, these detectors find application in DNA and protein detection. The performance of top and bottom electrode MSM structures with aluminum electrodes is compared. The measured results include a responsivity of 150 mA/W and an external quantum efficiency of 74% at a wavelength of 260 nm for the top electrode configuration at a bias of 2 V/mum and a 10-mum finger spacing.