Radiation Hardness of 4H-SiC P-N Junction UV Photo-Detector

Abstract

4H-SiC based p-n junction UV photo-detectors were irradiated with 600 keV He+ in the fluence range of 5 × 1011 ÷ 5 × 1014 ion/cm2 in order to investigate their radiation hardness. The effects of irradiation on the electro-optical performance were monitored in dark condition and in the UV (200 ÷ 400 nm) range, as well as in the visible region confirming the typical visible blindness of unirradiated and irradiated SiC photo-sensors. A decrease of UV optical responsivity occurred after irradiation and two fluence regimes were identified. At low fluence (<1013 ions/cm2), a considerable reduction of optical responsivity (of about 50%) was measured despite the absence of relevant dark current changes. The presence of irradiation induced point defects and then the reduction of photo-generated charge lifetime are responsible for a reduction of the charge collection efficiency and then of the relevant optical response reduction: point defects act as recombination centers for the photo-generated charges, which recombine during the drift/diffusion toward the electrodes. At higher irradiation fluence, the optical responsivity is strongly reduced due to the formation of complex defects. The threshold between low and high fluence is about 100 kGy, confirming the radiation hardness of SiC photo-sensors.

Integrating 2D layered materials with 3D bulk materials as van der Waals heterostructures for photodetections: Current status and perspectives

“…Ultraviolet detectors have important application value in the fields of environmental detection, biomedicine, national defense, military, and aerospace research. At present, the traditional wide‐gap semiconductor materials such as SiC, 104 Ga 2 O 3, 105 GaN, 106 and its ternary alloy AlGaN 107 have been used to realize high‐efficiency ultraviolet detectors. Among them, AlGaN has a tunable direct band gap of 3.4–6.2 eV and has excellent properties such as high electron mobility, high thermal stability, stable physical and chemical properties, and good radiation resistance, so it is widely regarded as one of the materials for making UV detectors 106,108 .…”

Recent Advances in Ethylene Gas Detection

“…The fabricated device demonstrated an acceptable repeatability ( Figure 7 e) and high sensitivity towards ethylene, with the highest sensing response of 1.6 µA (ΔI D , the difference of drain current before and after sensing the target gas) for 2.5 ppm of ethylene at the optimal operating temperature of 200 °C ( Figure 7 f). SiC-FET gas sensors should outperform OFET sensors in terms of stability considering that SiC-based devices can generally work at harsh conditions including high temperatures (SiC-FET, up to 225 °C) [ 74 ], high UV radiation hardness (SiC-UV photodetector, subject to the He + irradiation at 600 keV, with fluence range up to 5 × 10 14 ion·cm −2 ) [ 75 ], and extraordinary chemical inertness (SiC-MEMS (micro-electromechanical system), <1.5 nm·h −1 etching rate in micromachining solution (HF and KOH mixture)) [ 76 ]. Although, the inorganic FET-based ethylene gas sensor might be more practical for on-site implementation at this stage, the OFET type gas sensor for ethylene gas detection is still an attractive topic because of high flexibility and facile machinability of the materials.…”