High-Resolution X-Ray-Photoemission Spectra of PbS, PbSe, and PbTe Valence Bands

Abstract
High-resolution x-ray-photoemission valence-band spectra (0-45 eV binding energy) of cleaved single-crystal PbS, PbSe, and PbTe are reported. The spectra are compared with available band-theory results. Relativistic orthogonalized-plane-wave results exhibit the best over-all agreement with experiment. Empirical-pseudopotential-method (EPM) results show similar agreement for all but the most tightly bound valence band. The uppermost peak, corresponding to the three least tightly bound bands, shows detailed structure in good agreement with the EPM predictions. The PbTe valence-band spectrum can be synthesized from the x-ray-photoemission valence-band spectra of Pb and Te.