Photoelectron emission characteristics of diamond near the band gap

Total photoelectron yield was used to study the electron emission process o f diamond surfaces. The total electron emission intensity as a function of photon energy is measured between 2 and 6.2 eV and for temperatures between 300 and 600 It from hydrogenated and hydrogen-free surfaces. The yield spe ctra depend on the surface hydrogenation as well as on temperature. As the temperature is increased from 300 to 600 K, the change in emission intensit y is mainly observed near the band gap of diamond (from 5.2 to 5.5 eV) on b oth hydrogenated and hydrogen-free single crystal diamond surfaces but not for the CVD diamond film. The temperature dependence of the spectrum is exp lained by a combination of bulk and surface emission taking the temperature dependence of the diamond absorption coefficient into account. (C) 2000 El sevier Science S.A. All rights reserved.