Ultraviolet Photodetectors Based on 4H-SiC With Honeycomb-Like Light-Trapping Structures

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Silicon carbide (SiC) is a wide-bandgap semiconductor with excellent properties for photodetectors.
• Existing SiC UV detectors can be improved for enhanced performance.
• Visual-blind ultraviolet detection is crucial for various applications.

Purpose of the Study:

• To improve the performance of SiC-based UV detectors.
• To introduce and investigate honeycomb-like light-trapping microstructures on SiC surfaces.
• To explore the fabrication mechanism and optical effects of these microstructures.

Main Methods:

• Fabrication of honeycomb-like microstructures on SiC using photoelectrochemical (PEC) etching.
• Investigation of the anisotropic etching mechanism dependent on SiC crystal orientation.
• Optical characterization to assess UV reflection suppression and absorption enhancement.

Main Results:

• Honeycomb-like light-trapping microstructures were successfully fabricated on SiC.
• Optical characterization showed suppressed UV reflection and enhanced absorption.
• The self-powered SiC UV photodetector achieved a peak responsivity of 0.187 A/W at 290 nm (80% EQE).

Conclusions:

• The PEC etching method is effective for creating light-trapping microstructures on SiC.
• The microstructures significantly enhance UV detection capabilities by manipulating light.
• This technology offers a low-cost, scalable route to high-performance SiC UV photodetectors for imaging and communication.