Ultrahigh Sensitivity Graphene/Nanoporous GaN Ultraviolet Photodetectors

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Graphene integration with 3D semiconductors offers unique properties.
• Nanoporous materials can enhance optical characteristics.
• Ultraviolet (UV) photodetectors are crucial for optical sensing.

Purpose of the Study:

• To develop high-sensitivity UV photodetectors using graphene/nanoporous GaN heterojunctions.
• To investigate the effect of porosity on GaN optical properties.
• To evaluate the performance of the developed photodetectors.

Main Methods:

• Fabrication of monolayer graphene/nanoporous GaN heterojunctions.
• Characterization of nanoporous GaN using reflectivity, photoluminescence, and Raman spectroscopy.
• Performance testing of UV photodetectors, including response, detectivity, and UV-visible rejection ratio.

Main Results:

• Increased porosity of GaN improved its optical properties.
• The highest-porosity device exhibited rapid, linear UV response.
• Achieved ultrahigh detectivity (1.0 × 10^17 Jones) and UV-visible rejection ratio (4.8 × 10^7).

Conclusions:

• High sensitivity is attributed to enhanced light harvesting and graphene's properties.
• Graphene/nanoporous GaN heterojunctions show potential for selective weak UV signal detection.
• Simple and low-cost fabrication process makes these devices promising for future applications.