InN-based heterojunction photodetector with extended infrared response

Area of Science:

• Semiconductor Physics
• Materials Science
• Optoelectronics

Background:

• Gallium Nitride (GaN) based materials are crucial for optoelectronic devices.
• Extending photodetection capabilities to longer wavelengths in GaN systems presents a significant challenge.

Purpose of the Study:

• To explore the combination of Zinc Oxide (ZnO), Indium Nitride (InN), and Gallium Nitride (GaN) epitaxial layers.
• To achieve long-wavelength photodetection in GaN-based materials.
• To optimize the growth of InN for high-quality epitaxial layers.

Main Methods:

• Metalorganic Chemical Vapor Deposition (MOCVD) for epitaxial layer growth.
• Temperature-dependent photoluminescence (PL) to analyze InN thermal quenching and non-radiative processes.
• X-ray diffraction (XRD) and Energy Dispersive Spectroscopy (EDS) for material characterization.
• Fabrication and testing of ZnO/GaN/InN photodetectors.

Main Results:

• Optimized MOCVD growth conditions yielded high-quality InN epitaxial layers.
• PL studies revealed at least two non-radiative processes affecting InN transitions.
• XRD and EDS confirmed the successful incorporation of Indium and formation of the InN layer.
• The ZnO/GaN/InN system exhibited a double heterojunction band alignment.
• The fabricated photodetector achieved a long-wavelength quantum efficiency of 3.55% and strong photocurrent response under solar simulation.

Conclusions:

• The ZnO/GaN/InN heterojunction is a viable structure for long-wavelength photodetection.
• Optimized growth and material characterization are key to device performance.
• The demonstrated photodetector shows promising potential for advanced optoelectronic applications.