Magneto-photoluminescence study of type-II charge confinement in epitaxially grown GaInP2

We have studied the photoluminescence from GaInP2 grown by molecular beam epitaxy as a function of laser power, magnetic field and temperature. We show that the single luminescence peak observed in such samples arises from weakly bound (type-II) excitons in which the electrons are localised and the holes are free, and that it is the same as the additional low-energy peak typically observed in strongly CuPt-ordered GaInP2 grown by chemical vapour deposition techniques. We propose that the electron is confined in In-rich regions of the sample and the hole is delocalised by coupling between heavy- and light-hole bands.