Recent studies on diamond surfaces

The surface properties of diamond have been studied by ultra-violet photoemission spectroscopy (UPS), Kelvin probing and low energy electron diffraction (LEED). The atomic level structure of diamond surfaces was determined by LEED intensity vs. energy [I(E)] measurements in combination with Tensor LEED calculations. The LEED analysis of the C(100)-(2 x 1)-H surface revealed the formation of symmetrical dimers on the top carbon layer. For the C(100)-(1 x 1)-O surface, quantitative LEED analysis indicated a structural model where oxygen occupied the bridge site on the surface. Systematic investigations were carried out using UPS and a Kelvin probe measurement to reveal the effect of alkali metal fluoride overlayers on the work function of the diamond surfaces. LiF and RbF have been found to act as effective dipole layers to lower the surface work function and induce a negative electron affinity. (C) 2000 Elsevier Science S.A. All rights reserved.