Effects of hydrogen on the electronic properties of GaAsBi alloys, G. Pettinari, A. Patane, A. Polimeni, M. Capizzi, X.F. Lu, T. Tiedje, App. Phys. Lett. 101, 222103 (2012)

The effects of hydrogen incorporation on the electronic properties of Ga(AsBi) alloys are investigated in a wide range of Bi-concentration (0.6% < x < 10.6%) by Hall effect measurements in magnetic fields up to 14 T and by photoluminescence spectroscopy. For all the investigated Bi-concentrations, we report the passivation of Bi-induced shallow acceptor levels-responsible for the native p-type conductivity in Ga(AsBi)-and a tenfold increase of the hole mobility upon hydrogen incorporation in the host lattice. The emission energy is, instead, nE_g ligibly affected by hydrogenation, indicating that the narrowing of the band-gap energy with Bi and the native p-type conductivity are two uncorrelated effects arising from different Bi-induced electronic levels. Passivation by hydrogen of the shallow Bi-acceptor levels makes also possible to identify deep Bi-acceptor states.