Photoluminescence detection of shallow impurity neutralization in GaAs.

The neutralization of the shallow impurities in GaAs by atomic hydrogen is monitored by low-temperature photoluminescence spectroscopy. The reduced donor concentration after hydrogen plasma treatment gives rise to a diminished intensity of the donor-related optical transitions. While the overall photoluminescence intensity of the acceptor related transitions increases, the relative intensities of luminescence lines correlated with different acceptor species change. The behavior indicates a weak neutralization of even the shallow acceptors in GaAs.