Electro-optical properties of strained monolayer boron phosphide.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Chemistry

Background:

• Monolayer boron-phosphide (h-BP) is a 2D material with potential applications.
• Understanding strain effects is crucial for tuning h-BP's electronic and optical properties.
• Previous studies utilized DFT; this work introduces an enhanced theoretical approach.

Purpose of the Study:

• To investigate the impact of biaxial and uniaxial strain on the electronic and optical properties of h-BP.
• To propose a refined theoretical model incorporating on-site energy variation.
• To analyze changes in band gap, optical conductivity, and electron energy loss spectrum (EELS).

Main Methods:

• Tight-binding approximation
• Linear response theory
• Incorporation of on-site energy variation into the Hamiltonian
• Analysis of electronic band structure and optical spectra

Main Results:

• Tensile strain increases the band gap (max 1.45 eV), while compressive strain decreases it (min 1.14 eV).
• Strain shifts the optical absorption peak (around 4 eV) and influences optical conductivity.
• Biaxial strain preserves the isotropic optical properties of h-BP, whereas uniaxial strain induces anisotropy.

Conclusions:

• Strain engineering is an effective method to tune the electronic and optical characteristics of h-BP.
• The proposed theoretical approach provides a more nuanced understanding of strain effects.
• h-BP exhibits tunable optical anisotropy under uniaxial strain, opening possibilities for anisotropic devices.