Study on Quantum Efficiency Stability of Reflection-Mode GaN Negative Electronic Affinity Photocathode

摘要

The aim of this study is to analyze the decaying and recovering mechanism of the quantum efficiency for reflection-mode GaN NEA photocathode. One kind of reflection-mode GaN NEA photocathode is designed and grown in the laboratory. The quantum efficiency curves are obtained immediately and six hours later after the sample is fully activated, the quantum efficiency data at different wavelengths are acquired according to the two different quantum efficiency curves, Through the analysis of experiment result, the inner factors resulting in quantum efficiency decaying are discussed. Taking the factors into consideration, the method of supplementing Cs is applied in recovering the quantum efficiency, the quantum efficiency can be partly recovered. The reason that the quantum efficiency can not be completely recorvered is also anylized.