InN Quantum Dot Based Infra-Red Photodetectors

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Physics

Background:

• Indium nitride (InN) quantum dots (QDs) are promising for optoelectronic devices.
• Achieving controlled growth and understanding performance dependencies are crucial for InN QD applications.

Purpose of the Study:

• To grow self-assembled InN quantum dots on a Si(111) substrate.
• To investigate the effect of InN quantum dot density on metal-semiconductor-metal (MSM) photodetector performance.
• To validate experimental findings with device simulations.

Main Methods:

• Plasma-assisted molecular beam epitaxy (PA-MBE) for InN QD growth.
• X-ray diffraction and Field Emission Scanning Electron Microscopy (FESEM) for structural and morphological characterization.
• Fabrication of MSM photodetectors and electrical/optical measurements.
• Silvaco Atlas device simulation for validation.

Main Results:

• Successfully grew single-crystalline wurtzite InN QDs on Si(111).
• Controlled InN QD density by adjusting indium flux.
• Observed strong infrared response in the fabricated photodetectors.
• Demonstrated that higher InN QD density leads to lower dark current and higher photocurrent.

Conclusions:

• InN QD density is a critical parameter for optimizing photodetector performance.
• Higher InN QD densities improve photodetector characteristics by reducing leakage current and enhancing light absorption/carrier generation.
• The results provide a pathway for developing efficient InN-based infrared photodetectors.