Simulation of near-infrared photodiode detectors based on β-FeSi2/4H-SiC heterojunctions

In this paper, we propose a near-infrared p-type beta-FeSi2/n-type 4H-SiC heterojunction photodetector with semiconducting silicide (beta-FeSi2) as the active region for the first time. The optoelectronic characteristics of the photodetector are simulated using a commercial simulator at room temperature. The results show that the photodetector has a good rectifying character and a good response to near-infrared light. Interface states should be minimized to obtain a lower reverse leakage current. The response spectrum of the beta-FeSi2/4H-SiC detector, which consists of a p-type beta-FeSi2 absorption layer with a doping concentration of 1 x 10(15) cm(-3) and a thickness of 2.5 mu m, has a peak of 755 mA/W at 1.42 mu m. The illumination of the SiC side obtains a higher responsivity than that of the beta-FeSi2 side. The results illustrate that the beta-FeSi2/4H-SiC heterojunction can be used as a near-infrared photodetector compatible with near-infrared optically-activated SiC-based power switching devices.