Multiple Linear Dichroism Inversions in SnO Monolayers for Polarization-Sensitive UV Photodetection: An Ab Initio...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Tin monoxide (SnO) transitions from tetragonal to orthorhombic structure at the monolayer limit.
• The reduced symmetry of SnO monolayers impacts their electronic and optical characteristics.

Purpose of the Study:

• Investigate the electronic and optical properties of SnO monolayers with reduced orthorhombic symmetry (pmmn).
• Explore the consequences of in-plane anisotropy on light absorption and exciton behavior.

Main Methods:

• Utilized ab initio ground and excited-state calculations.
• Analyzed electronic band structure and optical absorption spectra.

Main Results:

• Observed asymmetric projections of electronic states, leading to polarization-dependent optical absorption.
• Demonstrated linear dichroism inversion in SnO monolayers across 200-400 nm wavelengths.
• Exciton state ordering dictates polarization-dependent absorption intensities.

Conclusions:

• SnO monolayers exhibit unique, frequency-dependent linear dichroism, unlike typical dichroic materials.
• These properties position SnO monolayers as promising for polarization-sensitive nanoscale devices.
• Optical dichroism can serve as a probe for the ferroelastic-to-paraelastic transition in SnO monolayers.