Comparative Photoemission Study of the CuInC Chalcopyrite Compounds

Photoemission spectra of all CuInC₂^VI chalcopyrite compounds are measured at Hel line excitation and of CuInS₂ also at excitation with ZrMζ radiation. It is found that the In5s – chalcogen p bonding states shift to lower binding energies with increasing anion mass. The energetic position of the S3s band of CuInS₂ is also determined. The experimental results obtained are compared with previous measurements and with theoretical band structure calculations.