Strain-tunable electronic, elastic, and optical properties of CaI₂ monolayer: first-principles study

ABSTRACT

The effects of biaxial strain on the electronic structure and the elastic and optical properties of monolayer CaI₂ were studied using first-principles calculations. The two-dimensional (2D) equation of state for monolayer CaI₂ as fit in a relative area of 80–120% is more accurate. The band gap can be tuned under strain and reached a maximum at a tensile strain of 4%. Under compressive strains, the absorption spectrum showed a significant red shift at higher strains. The static reflectance and static refractive index decreased in the strain range of −10% to 10%.

KEYWORDS:

• Monolayer CaI₂
• electronic structure
• elastic property
• optical property
• biaxial strain

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors are grateful for the supports of the NSAF [grant number U1830101], the Science Challenge Project [grant number TZ2016001], and the National Natural Science Foundation of China [grant number 11504035].