Potential of TiN/GaN Heterostructures for Hot Carrier Generation and Collection

Area of Science:

• Materials Science
• Nanotechnology
• Solid-State Physics

Background:

• Plasmonic applications require materials with specific optical properties.
• Gallium nitride (GaN) is a semiconductor with potential for hot carrier applications.
• Interfacial properties between plasmonic materials and semiconductors are crucial for device efficiency.

Purpose of the Study:

• To investigate the optical properties of titanium nitride (TiN) sputter-deposited on GaN.
• To analyze the interfacial characteristics of TiN/GaN systems with different doping (p-type and n-type).
• To evaluate the suitability of these interfaces for plasmonically generated hot carrier collection.

Main Methods:

• Sputter deposition of TiN thin films onto GaN substrates.
• Characterization of optical properties of the TiN/GaN interfaces.
• Electrical measurements to determine interfacial properties, including Schottky barrier height.

Main Results:

• TiN on GaN exhibits desirable optical properties for plasmonic applications.
• A Schottky barrier of approximately 0.56 eV formed on p-type GaN, facilitating electron-hole separation.
• No significant transport barrier was observed for TiN on n-type GaN, allowing for bias-dependent carrier control.

Conclusions:

• The TiN/GaN system is a viable candidate for plasmonic devices utilizing hot carriers.
• Doping-dependent interfacial properties offer distinct advantages for carrier management in different applications.
• The choice between p-type and n-type GaN depends on the desired mechanism for hot carrier collection and utilization.