Fe-doped and (Zn, Fe) co-doped CdS films:: Could the Zn doping affect the concentration of Fe2+ and the optical properties?

Cd1-xFexS and Cd1-x-yFexZnyS thin films were grown by low-pressure metal organic chemical vapor deposition (LP-MOCVD) on c-Al2O3 substrates. The films fabricated at 360 degrees C under an hydrogen pressure of 76 Torr had hexagonal structure with only one (0002) diffraction peak. The samples with low doping content have sharp absorption edges. It is found that the absorption edge and the emission peak positions of the Cd1-x-yFexZnyS film shift to high energy due to the Zn-doping. The band gap energy could be tuned in a wide range with the change of Zn content. The broadening of the Cd1-x-yFexZnyS emission peak could be attributed to the alloy fluctuations and the shallow defect in the samples. (c) 2006 Elsevier B.V. All rights reserved.