  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.
