The effects of treatments with hydrogen plasma (hydrogenation) and of subsequent annealing (dehydrogenation) on the photoluminescence efficiency and on the net donor and deep level concentrations in AlxGa1-xAs grown by molecular beam epitaxy are reported. It is shown that hydrogenation results in the passivation of the shallow donors, whose electrical and optical activities are partially restored after dehydrogenation. It is also shown that deep centres such as ME5, ME6 and DX are passivated by hydrogenation. The DX centre is restored to a significant extent by dehydrogenation, whereas the ME5 and ME6 defects are reactivated only to a minor extent. The strong increase in the PL efficiency observed after hydrogenation and its dependence on growth temperature are shown to be consistent with the dominant role of the ME5 and ME6 centres on the non-recombination process in AlxGa-xAs.
Effects of hydrogenation of deep and shallow levels in AlGaAs grown by MBE
1994
Abstract
The effects of treatments with hydrogen plasma (hydrogenation) and of subsequent annealing (dehydrogenation) on the photoluminescence efficiency and on the net donor and deep level concentrations in AlxGa1-xAs grown by molecular beam epitaxy are reported. It is shown that hydrogenation results in the passivation of the shallow donors, whose electrical and optical activities are partially restored after dehydrogenation. It is also shown that deep centres such as ME5, ME6 and DX are passivated by hydrogenation. The DX centre is restored to a significant extent by dehydrogenation, whereas the ME5 and ME6 defects are reactivated only to a minor extent. The strong increase in the PL efficiency observed after hydrogenation and its dependence on growth temperature are shown to be consistent with the dominant role of the ME5 and ME6 centres on the non-recombination process in AlxGa-xAs.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.