In Pursuit of 2D Materials for Maximum Optical Response

Area of Science:

• Materials Science
• Condensed Matter Physics
• Optoelectronics

Background:

• Two-dimensional (2D) materials exhibit significant electron-photon interactions.
• Strong optical responses are crucial for light modulation and manipulation applications.
• Existing materials often have limitations in optical performance across various wavelengths.

Purpose of the Study:

• To determine the theoretical limits of optical response (absorbance and reflectance) in 2D materials.
• To computationally survey 2D materials for optimal optical properties.
• To identify 2D materials suitable for ultrathin reflectors and absorbers in optoelectronics.

Main Methods:

• Qualitative analytical modeling and first-principles calculations.
• Computational survey across mid-infrared to deep-ultraviolet frequencies.
• Quasiparticle energy calculations and Bethe-Salpeter equation for excitonic effects.

Main Results:

• 2D boron demonstrates broadband reflectance >99% for over 100 layers, exceeding conventional thin films.
• Several monolayer semiconductors achieve absorbance >30%, surpassing half the theoretical limit.
• Identified materials show potential for ultrathin reflectors and absorbers.

Conclusions:

• 2D materials possess exceptional optical properties for subwavelength light modulation.
• 2D boron and specific semiconductors are promising candidates for advanced optoelectronic devices.
• The study provides a roadmap for utilizing 2D materials in optical applications.