DEFECT SPECTROSCOPY AND DETERMINATION OF THE ELECTRON-DIFFUSION LENGTH IN SINGLE-CRYSTAL DIAMOND BY TOTAL PHOTOELECTRON YIELD SPECTROSCOPY

Novel photoelectron yield experiments performed with a dynamical range of 8 orders of magnitude reveal a new excitation channel for electron emission on diamond (100) and (111) surfaces with negative electron a ffinity which is due to defect states 2.0 and 4.1 eV below the conduct ion band minimum. Analyzing the competition of free conduction band el ectrons excited out of defects and excitons with respect to final phot oelectron production we determine that the electron diffusion length i n p-type IIb diamond is between 150 and 250 mu m.