Electronic passivation of GaAs surfaces by electrodeposition of organic molecules containing reactive sulfur

A scheme for the surface passivation of GaAs is demonstrated by using electrolytically deposited organic thin molecular layers with terminating reactive sulfur (-S^-) atoms. This method has an advantage, as a way of fabricating insulator on GaAs, that it is essentially free from surface layer damage which would otherwise be produced when conventional energetic processes are employed to make up insulating layers. Steady-state photoluminescence, Raman scattering, and x-ray photoelectron spectroscopy were used to characterize electronic properties of the passivated surface. Significant reduction both in the surface recombination rate and the adverse band bending due to surface states is shown by implementing an insulator layer created with a simplified process.