Tailoring of Bandgap to Tune the Optical Properties of Ga_1-xAl_xY (Y = As, Sb) for Solar Cell Applications by Density Functional Theory Approach

The bandgap was tuned to investigate the electronic and optical aspects using first-principle calculations for solar cells and other optical applications. The bandgap range varies from 1.6 to 2.1 eV for Ga_{1- x}Al_xAs and from 0.8 to 1.5 eV for Ga_{1- x}Al_xSb (x = 0.0, 0.25, 0.5, 0.75, 1.0). The dispersion, polarisation, and attenuation have been illustrated in terms of transparency and maximum absorption of light. The inversion of polarised atomic planes near the resonance allows the maximum absorption in ultraviolet to visible region. The Penn's model (ϵ₁(0) ≈ 1 + (?ω_p/E_g)²) and optical relation ϵ1(0)${\varepsilon-{1}}\left(0\right)$ = n²(0) confirm the reliability of our finding. The maximum absorption, optical conduction, and minimum optical energy loss increase the credibility of the studied materials for energy storage device manufacture.