Reversibility of the effects of hydrogen on the electronic properties of InxGa1−xAs1−yNy

The effects of post-growth hydrogen irradiation and subsequent thermal annealing on the electronic properties of (InGa)(AsN) single quantum wells (QWs) have been studied by photoluminescence spectroscopy. We find that the QW effective band gap increases as a result of hydrogen irradiation and may reach the value it has in a N-free reference sample. Thermal annealing, instead, restores the optical properties the QW had before hydrogenation. These results are accounted for by the formation of N–H complexes, with an ensuing N passivation and a reduction of the effective N concentration. By means of isochronal annealings performed at different temperatures we determine the activation energy for the dissociation of such complexes, which has a Gaussian distribution. We attribute this finding to N clusters with different size forming different H–N bonds.