The sulfur passivation of an n-GaN surface was investigated by employing an aqueous (NH 4 ) 2 S solution and (NH 4 ) 2 S+t-C 4 H 9 OH solution. Photoluminescence and Auger electron spectroscopy revealed that treatment with (NH 4 ) 2 S+t-C 4 H 9 OH results in a more effective passivation of the n-GaN surface than that with (NH 4 ) 2 S due to a higher chemical reactivity of sulfur species in the former solution. The (NH 4 ) 2 S+t-C 4 H 9 OH-treated sample shows a stronger photoluminescence intensity by a factor of 2.5 with respect to an untreated sample. In addition, improved Ohmic characteristics of the sample are evident from current-voltage measurements. This result can be attributed to the effective removal of an insulating layer on the n-GaN surface.
ASJC Scopus subject areas
- Physics and Astronomy(all)