Applied Physics Letters · 1988 · 69 citations · 5 references
Materials ScienceSodium Sulfide TreatmentElectrical EngineeringSurface CharacterizationEngineeringPhysicsSurface ScienceApplied PhysicsSemiconductor MaterialFermi LevelThin FilmsBand BendingMicroelectronicsMolecular Beam EpitaxyOptoelectronicsCompound Semiconductor
Recent evidence suggests that sodium sulfide treatment of GaAs surfaces results in the reduction of surface recombination and in Fermi level unpinning. We have used a surface conductivity technique to measure the Fermi level position of samples with and without sodium sulfide treatment. This method has specific advantages over spectroscopic techniques for studying thin films on GaAs. Photoluminescence (PL) measurements were used to qualitatively evaluate surface recombination. We conclude that while the reduction of surface recombination is attained, the surface is not unpinned.
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