4H–SiC Metal–Semiconductor–Metal Ultraviolet Photodetectors in Operation of 450 $^{\circ}\hbox {C}$

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 × 10⁵ 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.