High-performance visible to near-infrared photodetectors by using (Cd,Zn)Te single crystal.

The authors report on a high-performance metal-semiconductor-metal (MSM) photodetector fabricated on the CdZnTe single crystal with the photoresponse from visible to near infrared region. Benefitting from the high-quality single crystallization, an ultra-low dark current of ~10 A was obtained at a high applied voltage of 10 V, leading to a photo-to-dark-current ratio of more than 10 at 700 nm light illumination. The highest responsivity is estimated to be 1.43 A/W with a specific detectivity of 3.31 × 10 Jones at 10 V at a relatively lower injection power density. The discrimination ratio between the near infrared region of 800 nm and 900 nm is almost 10, which is high enough for the accurate spectra selectivity. The MSM photodetector also exhibits a fast response speed of ~800 μs and extremely low persistent photoconductivity (PPC), while the PPC is inhibited at high temperatures.