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Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
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Bi2O2Se for broadband terahertz wave switching
Applied Optics
|December 28, 2020
Summary
Researchers developed a novel terahertz wave switch using a Bismuth Oxy-Selenide (Bi2O2Se)/Silicon structure. This device achieves fast switching speeds and high extinction ratios for dynamic terahertz wave manipulation.
Area of Science:
- Terahertz (THz) Photonics
- Materials Science
- Semiconductor Devices
Background:
- Dynamic manipulation of terahertz waves is crucial for advanced terahertz systems.
- Existing terahertz wave control methods often face limitations in speed or efficiency.
Purpose of the Study:
- To propose and demonstrate a novel terahertz wave switch.
- To investigate the terahertz wave modulation capabilities of a Bismuth Oxy-Selenide (Bi2O2Se)/Silicon (Si) heterostructure.
Main Methods:
- Fabrication of a Bi2O2Se/Si heterostructure device.
- Terahertz time-domain spectroscopy (THz-TDS) for measuring transmittance and conductivity.
- Analysis of terahertz characteristics using the Drude model.
Main Results:
- Achieved an ON-OFF switching speed of 2 MHz.
- Obtained an extinction ratio of 17.7 dB at 1.3 W/cm² laser irradiance.
- Demonstrated carrier accumulation at the interface induces strong terahertz absorption.
Conclusions:
- The Bi2O2Se/Si structure effectively enables dynamic terahertz wave switching.
- The device shows potential for tunable terahertz functional devices.
- Viable applications in terahertz communication, imaging, and sensing are anticipated.
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