Published online by Cambridge University Press: 21 February 2011
We report photoemission measurements from the (111)2×1 diamond-titanium monoxide (TiO) interface. Submonolayer deposition of TiO on the (111)2×1 diamond surface modifies the electron affinity of the surface from positive to negative. No change in the band bending was observed as a result of the TiO deposition. Total electron yield measurements from the diamond-TiO interface were also performed. The yield spectra, as expected for a negative electron affinity (NEA) surface, have emission thresholds that are in good agreement with the absorption coefficient of diamond. To further understand the emission properties of NEA (111) diamond surfaces we also compare the electron yield photo-excitation spectra of the diamond-TiO interface with the yield spectra of hydrogenated (111)1×1:H diamond surfaces.