The first data evidencing the existence of the donor level of the interstitial H in GaAs were presented. The abundant formation of the (0/+) donor level after in situ low-temperature implantation of H into the depletion layer of GaAs Schottky diodes was observed and the activation energy and annealing properties were determined by Laplace DLTS. The activation energy for electron emission of this donor state was 0.14eV. Above 100K the H deep donor state was unstable, converting to a more stable form when there were electrons available for the capture process. A slightly perturbed form of the H donor in its neutral charge state could be recovered by illuminating the sample. This process releases twice as many electrons as the ionization process of the H donor state itself. This fact, by analogy with the Si case, evidences the negative-U behaviour of H in GaAs.

Donor Level of Interstitial Hydrogen in GaAs. L.Dobaczewski, K.Bonde Nielsen, A.Nylandsted Larsen, A.R.Peaker: Physica B, 2006, 376-377, 614-7