Electronic properties of AlxGa1-xAs surface passivated by ultrathin silicon interface control layer

The photoluminescence surface state spectroscopy (PLS3) method was applied to a study of the surface state distribution (N-SS), effective surface reco mbination velocity (S-eff), electron (E-Fn) and hole (E-Fp) quasi-Fermi lev els and band bending (V-S) on the Al0.33Ga0.67As surface air-exposed and pa ssivated by the Si interface control layer (ICL) technique. Using the detai led measurements of the PL quantum efficiency for different excitation inte nsities, combined with the rigorous computer simulations of the bulk and su rface recombination processes, the behavior and correlation among the surfa ce characteristics under photo-excitation was determined. The present analy sis indicated that forming of a Si3N4/Si ICL double layer (with a monolayer level control) on AlGaAs surface reduces the minimum interface state densi ty down to 10(10) cm(-2) eV(-1) and surface recombination velocity to the r ange of 10(4) cm/s under low excitations. (C) 1999 Elsevier Science B.V. Al l rights reserved.