PHOTON ENERGY-DEPENDENCE OF THE LASER-INDUCED EMISSION YIELD OF SI ATOMS FROM THE SI(100) 2X1 SURFACE

We have carried out measurements of the temperature dependence of the emission yield of Si atoms from the Si(100) 2 x 1 surfaces induced by nanosecond laser pulses of several photon energies. The yield is plott ed as a function of E = hv - E(G)(T), where hv is the photon energy an d E(G)(T) is the band-gap energy at temperature T where the yield is m easured. We find that the Si emission yield is within the noise level for E = 0.9 - 1.15 eV (region I), increases to a saturation level for E = 1.15 - 1.42 eV (region II) and increases further for E = 1.42 - 2. 15 eV (region III). The results are compared with those for GaP, GaAs and InP.