X-RAY-FLUORESCENCE SPECTROSCOPY OF CU-IN-SE CHALCOPYRITE-STRUCTURE THIN-FILMS

In x-ray fluorescence spectroscopy we have observed a positive shift of the Cu L(alpha) x-ray energy with an increase of the number of excess electrons in the electron-doped Cu-In-Se chalcopyrite-structure thin films. This positive shift can be reproduced well by the energy calculation using the Hartree-Fock-Slater method by taking into account the Cu 4s-3d rehybridization effect. We discovered that the excess electrons entered into the lower conduction band dominated by the Cu 4s orbital in the n-type Cu-In-Se thin films deposited by a molecular-beam method.