Spectral Analysis of Photoemissive Yields in Si, Ge, GaAs, GaSb, InAs, and InSb

The data of Allen and Gobeli on photoemissive yields from partially cesiated surfaces of several semiconductors with photon energies between 2 and 6 eV are analyzed in detail. The results are shown to be consistent with direct transitions in energy-band models obtained from semiempirical pseudopotentials based on interband optical edges. The correlation with reflectivity structure is good, and several new transitions are resolved which were not apparent in previous optical studies.