4 H – SiC Metal – Semiconductor – Metal Ultraviolet Photodetectors in Operation of 450 ◦ C

This work demonstrates the high-temperature operation of metal–semiconductor–metal (MSM) photodetectors (PDs) up to 450 ◦C using lightly Al-doped epitaxial 4H–SiC thin films. The responsivity of the PDs under 325-nm illumination is 0.0305 A/W at 20-V bias at room temperature. The photocurrentto-dark-current ratio of the SiC MSM PDs is as high as 1.3 × 10 at 25 ◦C and is 0.62 at 450 ◦C. The rise/fall time of the PDs is increased slightly from 594 μs/684 μs to 684 μs/786 μs as the temperature increases from room temperature to 400 ◦C. These results support the use of 4H–SiC PDs in extremely high temperature applications.