Photoelectron Emission from the Cesiated Diamond (110) Surface

Abstract

ABSTRACTCesiation of type IIB diamond (110) crystals was studied using a combination of ultraviolet photoemission spectroscopy, x-ray photoemission spectroscopy, and low energy electron diffraction. The diamond (110) crystal was hydrogen treated by exposure to a hydrogen microwave discharge. Although cesium was largely unreactive with the hydrogenated diamond surface, cesiation yielded a large enhancement in the secondary electron yield of the diamond surface and the negative electron affinity (NEA) condition. An increase in the downwards band bending of approximately 0.75-0.9 eV was inferred from the shift in the valence band edge following cesiation. In addition, (lx 1) LEED patterns were observed at all cesium coverages. Exposure of the cesiated diamond surface to molecular oxygen significantly reduced the NEA peak (relative to the secondary electron background); however, recovery of the NEA peak was observed when the molecular oxygen source was removed.