Band bending, Fermi level pinning, and surface fixed charge on chemically prepared GaAs surfaces

E. Yablonovitch, Brian Skromme, R. Bhat, J. P. Harbison, T. J. Gmitter

Research output: Contribution to journalArticle

77 Scopus citations


We compare the nature of the band bending under GaAs surfaces prepared by alkaline sulfides [Na2S9H2O, (NH4) 2S] with that under oxidized GaAs surfaces. We make the point that Fermi level pinning implies band bending, but band bending does not necessarily imply "pinning." In either case, even weak light illumination substantially flattens the bands. On ammonium sulfide treated surfaces the fixed and trapped charge density in the dark is only ∼5×101 1 electrons/cm2, but these few states are mostly neutralized at low-level forward injection. This behavior should not be confused with Fermi level pinning.

Original languageEnglish (US)
Pages (from-to)555-557
Number of pages3
JournalApplied Physics Letters
Issue number6
Publication statusPublished - 1989
Externally publishedYes


ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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