Lattice relaxation by atomic hydrogen irradiation of InGaAsN/GaAs semiconductor alloys

We study the effect of hydrogen incorporation on the lattice properties of InxGa1–xAs1–yNy/GaAs heterostructures. The band gap widening observed in the photoluminescence spectra of hydrogenated GaAs1–yNy and InxGa1–xAs1–yNy is accompanied by a lattice expansion along the growth direction, as measured by x-ray diffraction. At the same time, far-infrared spectroscopy reveals that a Ga-N local vibrational mode at ~472 cm–1 disappears upon hydrogen irradiation. All these effects are reversed upon hydrogen removal from the hydrogenated samples by thermal annealing. Finally, first-principles calculations indicate that a same di-hydrogen complex is responsible for both the band gap reopening and the lattice expansion of hydrogenated InxGa1–xAs1–yNy.