Ultrafast frequency-agile terahertz devices using methylammonium lead halide perovskites

Area of Science:

• Metamaterials Science
• Terahertz Technology
• Semiconductor Physics

Background:

• Metamaterial structures offer tunable responses crucial for terahertz (THz) devices.
• Existing THz metamaterials often lack dynamic frequency agility and multi-functionality.
• Perovskite semiconductors present opportunities for light-controlled material properties.

Purpose of the Study:

• To demonstrate ultrafast frequency-agile terahertz metamaterial devices.
• To enable precise control over terahertz resonant responses using multiple perovskites.
• To explore new functionalities in terahertz devices through multi-perovskite integration.

Main Methods:

• Developed a novel fabrication technique to pattern multiple perovskites with micrometer precision, protecting deposited layers from solvents.
• Utilized optical pumping with varying fluence and wavelength to control perovskite properties.
• Integrated perovskites within split-ring resonator structures for terahertz response manipulation.

Main Results:

• Demonstrated terahertz resonant response tuning based on optical pump fluence and wavelength.
• Achieved ultrafast switching between terahertz resonances due to subnanosecond photocarrier recombination lifetimes in polycrystalline perovskites.
• Showcased selective tuning and suppression of terahertz resonance using different optical wavelengths on a dual-perovskite system.

Conclusions:

• The developed fabrication method allows for precise patterning of multiple perovskites in close proximity.
• Ultrafast, wavelength- and fluence-tunable terahertz metamaterial devices are achievable.
• This multi-perovskite approach enables novel functionalities for advanced terahertz applications in spectroscopy and communications.