First principles investigation of Be3X2 (X=N, P, As) and their alloys for solar cell applications

Abstract

The ground state electronic structure and absorption efficiency of α-Be3X2 (X = N, P or As)and their alloys are investigated using density functional theory. All pristine compounds and alloys are found to have direct band gaps at the zone center Γ point. The Be24PxN16-x and Be24AsxN16-x alloys (x = 4, 8, 12, or 16)are predicted to have suitable band gaps for solar absorber applications. The majority interband electronic transitions in the pristine compounds and the alloys are between the valence band p-states of N, P and As and the conduction band p-states of Be. The alloy systems show strong and wide absorption spectra, suggesting potential solar energy conversion applications.