Ag@WO₃ core-shell nanocomposite for wide range photo detection

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Photodetectors are crucial for light sensing applications.
• Developing efficient and cost-effective photodetectors remains an active research area.
• Core-shell heterostructures offer unique properties for advanced optoelectronic devices.

Purpose of the Study:

• To synthesize high-performance photodetectors using Ag-WO3 core-shell heterostructures.
• To investigate the electrical and photoresponse characteristics of the Ag@WO3 nanocomposite heterojunction.
• To evaluate the potential of these devices for light detection applications.

Main Methods:

• Two-step pulsed laser ablation in water for synthesizing Ag-WO3 core-shell nanostructures.
• Hall effect measurements to determine electrical properties (n-type conduction, Hall mobility).
• Current-voltage (I-V) measurements to assess rectification and heterojunction behavior.
• Photoresponse measurements (responsivity, detectivity, response time, EQE) under UV and visible light illumination.

Main Results:

• Synthesized Ag@WO3 exhibits n-type conduction with high Hall mobility (1.25 × 10^3 cm^2V^-1S^-1).
• The Ag-WO3/n-Si heterojunction shows good rectification (factor ~1.71 at 5V) and responsivity peaks in UV/visible regions.
• High detectivity (e.g., 3.5 × 10^14 Jones at 350 nm) and rapid response times (<100 ms) were achieved.
• Maximum external quantum efficiency (EQE) of 11.5% at 350 nm was observed.

Conclusions:

• The synthesized Ag-WO3 core-shell heterostructures are suitable for high-performance photodetector applications.
• The developed photodetectors exhibit excellent UV and visible light sensitivity with fast response.
• The simple and economical synthesis method makes these devices promising for practical applications.