Evaluation of a cesium iodide photocathode assisted with MgO-coated multiwall carbon nanotubes

Abstract

This paper reports the enhanced photocurrent and relative quantum efficiency of cesium iodide (CsI) films on magnesium oxide (MgO)-coated multiwall carbon nanotubes (MWCNTs) on a silica substrate, i.e., CsI/MgO/MWCNTs/Si, when illuminating with 147 nm photons under an external electric field. The incorporation of MWCNTs resulted in significant enhancement of the photocurrent by several orders of magnitude compared to that of a conventional CsI. An analysis of the photoelectron energy spectrum attributed the phenomena to the creation of a very high electric field through the MgO/CsI film with the subsequent generation of avalanche secondary electrons.