Electronic properties of CdSe and Cd1_xFexSe wurtzite compounds: XANES measurements and analysis

The L1 and L3 edges of Cd and the K edges of Fe and Se have been examined for CdSe and Cd1?xFexSe (x=0.22) wurtzite crystals by the X-ray absorption technique. The experimental results are compared with the calculated conduction band electronic densities of states of the CdSe and Cd3FeSe4 wurtzite crystals [J. Konior, J. Goniakowski, S. Kaprzyk, J. Alloys Comp. 328 (2001) 139], respectively. A good agreement is found between the experimental and theoretical results. Then, using the virtual crystal model for Cd1?xFexSe, the hypothetical wurtzite structure of FeSe, denoted as FeSe(w), as well as a hybridized contribution of FeSe(w) in Cd1?xFexSe have been extracted. Comparing these data with CdSe, taken as a standard compound, the extracted contributions show p-like behavior around Se ions, at about 2 eV below and at 8 and 18 eV above the corresponding energy of the CdSe conduction band minimum. A negligible contribution of FeSe(w) around Cd ion has been ascertained.