Lateral metal-semiconductor-metal photodetectors based on amorphous selenium

We report a lateral metal-semiconductor-metal (MSM) photodetector (PD) based on an amorphous selenium (a-Se). The PD exhibits a dark current below 200 fA under electric fields ranging from 6 to 12 V/μm, a responsivity of up to 0.45 A/W, a photogain of 1.2 near short wavelengths of 468 nm, and a high-speed photoresponse with a rise time of 50 μs, fall time of 60 μs, and time constant of 30 μs, respectively. The lateral MSM PD based on a-Se has great potential for use in digital x-ray imaging applications.