Influence of surface carbon on the performance of cesiated p-GaN photocathodes with high quantum efficiency.

ABSTRACT: This study shows residual surface carbon's influence on photocathodes' quantum efficiency based on p-GaN grown on sapphire by metal organic chemical vapor deposition. An X-ray photoelectron spectrometer (XPS) built in an ultrahigh vacuum system allowed the in-situ monitoring of the photocathode surface beginning immediately after their cleaning and throughout the activation and degradation processes. An atomically clean surface is necessary to achieve a negative electron affinity, which is the main prerequisite for high quantum efficiency. The p-GaN samples were cleaned with ethanol and underwent a sub-sequential thermal vacuum cleaning. Although carbon and oxygen contaminations are expected to be undesired impurities from the metal organic chemical vapor deposition, which remained on the

SUBMITTER: Schaber J 

PROVIDER: S-EPMC9950145 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature