  The modification of the nature and size of bandgaps for III-V semiconductors is of strong interest for optoelectronic applications. Strain can be used to systematically tune the bandgap over a wide range of values and induce indirect-to-direct (IDT), direct-to-indirect (DIT), and other changes in bandgap nature. Here, we establish a predictive ab initio approach, based on density functional theory, to analyze the effect of uniaxial, biaxial, and isotropic strain on the bandgap. We show that systematic variation is possible. For GaAs, DITs were observed at 1.52% isotropic compressive strain and 3.52% tensile strain, while for GaP an IDT was found at 2.63% isotropic tensile strain. We additionally propose a strategy for the realization of direct-indirect transition by combining biaxial strain with uniaxial strain. Further transition points were identified for strained GaSb, InP, InAs, and InSb and compared to the elemental semiconductor silicon. Our analyses thus provide a systematic and predictive approach to strain-induced bandgap tuning in binary III-V semiconductors. 
Systematic strain-induced bandgap tuning in binary III-V semiconductors   from density functional theory