Two-dimensional tellurium-polymer membrane for ultrafast photonics

Area of Science:

• Materials Science
• Nanotechnology
• Photonics

Background:

• Tellurium (Te) possesses unique thermoelectric, photoelectronic, and piezoelectric properties, making it valuable for various electronic and energy devices.
• Two-dimensional (2D) materials offer enhanced properties due to their reduced dimensionality, attracting significant research interest.

Purpose of the Study:

• To fabricate ultrathin two-dimensional (2D) tellurium (Te) nanosheets using a cost-effective liquid-phase exfoliation method.
• To investigate the nonlinear optical properties and potential applications of a 2D Te/PVP membrane in ultrafast photonics.

Main Methods:

• Facile and cost-effective liquid-phase exfoliation was employed to synthesize 2D Te nanosheets.
• The 2D Te nanosheets were mixed with polyvinylpyrrolidone (PVP) to form a uniform 2D Te/PVP membrane.
• Open-aperture Z-scan technology was used to characterize nonlinear optical properties over a broad spectral range (800-1550 nm).

Main Results:

• The 2D Te/PVP membrane demonstrated excellent mechanical, thermal, and stability properties.
• A large nonlinear absorption coefficient (approximately 10⁻¹ cm GW⁻¹) was observed across the tested wavelength range, indicating broadband saturable absorption.
• A stable femtosecond laser with a pulse duration of 829 fs was successfully generated using the 2D Te/PVP membrane as a saturable absorber (SA).

Conclusions:

• The 2D Te/PVP membrane exhibits efficient broadband saturable absorptivity, making it suitable for photonic applications.
• This study highlights the potential of 2D Te/PVP membranes for ultrafast photonics and positions Te as a promising 2D material for devices like all-optical modulators and switches.