Semiconductor surfaces offer efficient pathways for injecting native point defects into the underlying bulk. Adsorption of a suitably chosen foreign element serves to modulate the injection rate, even at small percentages of a monolayer. Through self-diffusion experiments using isotopic exchange with labeled oxygen, the present work demonstrates such behavior in the case of sulfur adsorption on c-axis Zn-terminated ZnO(0001), wherein the clean surface injects with exceptional efficiency. The experiments provide strong evidence that the injection sites comprise only a small fraction of the total surface atom density and that sulfur adsorption merely blocks those sites. Comparison with related systems shows this simple mechanism is surprisingly uncommon.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films