Visible-Blind Photodetector Based on p-i-n Junction 4H-SiC Vertical Nanocone Array

In this article, we report the first experimental results of a novel 4H-silicon carbide (SiC) p-i-n photodetector based on a vertical nanocone array (NCA). It is fabricated by electron beam lithography and inductively coupled plasma (ICP) etching technology. The performance of static and dynamic behavior was studied systematically. It shows the responsivity of ~41.9 mA/W under 360 nm at a bias voltage of -0.5 V and has a linear response to the ultraviolet (UV) light in a wide light intensity range of 0.1-10⁴ mW/cm². The response time decreased as the light intensity rose from 3 mW/cm² to 5 W/cm² and then leveled off at higher light intensity (>100 mW/cm²), which is about 0.25 ms. The photodetector -3-dB cutoff is ~3400 Hz at λ = 360 nm and light intensity = 100 mW/cm². Besides, the detector can respond to the UV light from 260 to 360 nm and the peak responsivity is ~78 mA/W at 320 nm. The analysis results have reference values for the development of an innovative 4H-SiC UV photodetector to some extent.