Extreme temperature 4H-SiC metal-semiconductor-metal ultraviolet photodetectors

This work demonstrates high-temperature operation of metal-semiconductor-metal photodetectors (MSM PDs) using lightly Al-doped epitaxial 4H-SiC thin films. The responsivity of the PDs under 325 nm illumination is 0.116 A/W at a 20 V bias at room temperature. The photo-to-dark current ratio of SiC MSM PDs is as high as 1.3×10⁵ at 25°C and is 22 at 400°C. The rise time of PDs is increased slightly from 594 μs to 684 μs from room temperature to 400°C. These results support the use of 4H-SiC thin films photodetectors in extreme high-temperature applications.