Unpinning of surface state at 0.92 eV by nanocrystalline ZnSe on GaAs

A thin film of nanocrystalline ZnSe was deposited on GaAs by a chemical met hod and the resulting heterostructure was characterized for its passivating behavior. A remarkable enhancement in the intensity of photoluminescence o f GaAs at 875 nm was achieved as a consequence of the deposition. The passi vating effects of nanocrystalline ZnSe was confirmed by thermally stimulate d exoelectron emission spectroscopy, a surface technique for gap state anal ysis. The disappearance of the peak related to the pinned Fermi level posit ion at 0.92 eV below the conduction band edge was the resulting feature. A nanocrystalline growth of ZnSe was observed an GaAs by scanning electron mi croscopy. (C) 2001 Elsevier Science B.V. All rights reserved.