Polarization Sensitive Vacuum-Ultraviolet Photodetectors Based on m-Plane h-BN

Area of Science:

• Materials Science
• Optoelectronics
• Solid State Physics

Background:

• Vacuum ultraviolet (VUV) detection is crucial for space science, radiation monitoring, and fundamental research.
• Polarization detection enhances VUV signal comprehension but is limited by material constraints.
• Existing VUV detectors lack materials with low-symmetry structures, VUV selectivity, and radiation resistance.

Purpose of the Study:

• To develop a VUV polarization-sensitive photodetector.
• To explore the potential of hexagonal boron nitride (h-BN) for VUV polarization detection.
• To overcome limitations of current VUV detection technologies.

Main Methods:

• Wafer-scale epitaxial growth of m-plane hexagonal boron nitride (h-BN) films.
• Characterization of anisotropic light absorption and charge carrier transport.
• Fabrication and testing of an h-BN based VUV photodetector.

Main Results:

• Demonstrated significant anisotropy in h-BN films due to space symmetry breaking.
• Achieved a dichroic ratio greater than 10 and a carrier transport efficiency ratio of 24.
• Obtained a high polarization ratio of 6.2 for 188 nm VUV light, setting a new benchmark.

Conclusions:

• h-BN films provide an effective platform for designing polarized VUV photodetectors.
• This work advances VUV detection capabilities and opens avenues for integrated optoelectronics.
• The developed technology holds promise for applications in advanced photonics and electronics.