Deformation potentials can be determined by measuring the variation of
the energy of the electronic transitions with strain. In this work, t
he hydrostatic and shear potentials of the band-gap electronic transit
ion (E0) and the transitions along the [111] direction (E1) of GaAs1-x
Px, x almost-equal-to 0.20, have been determined by electroreflectance
characterization of GaAs1-xPx layers with different levels of strain.