Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5361123 | Applied Surface Science | 2008 | 5 Pages |
Abstract
High quality cubic CdS epilayers were grown on GaAs (1 0 0) substrates by the hot-wall epitaxy method. The crystal structure of the grown epilayers was confirmed to be the cubic structure by X-ray diffraction patterns. The optical properties of the epilayers were investigated in a wide photon energy range between 2.0 and 8.5 eV using spectroscopic ellipsometry (SE) and were studied in the transmittance spectra at a wavelength range of 400-700 nm at room temperature. The data obtained by SE were analyzed to find the critical points of the pseudodielectric function spectra, ãÉ(E)ã = ãÉ1(E)ã + iãÉ2(E)ã, such as E0, E1, E2, Eâ²0, and Eâ²1 structures. In addition, the optical properties related to the pseudodielectric function of CdS, such as the absorption coefficient α(E), were investigated. All the critical point structures were observed, for the first time, at 300 K by ellipsometric measurements for the cubic CdS epilayers. Also, the energy band gap was determined by the transmittance spectra of the free-standing film, and the results were compared with the E0 structure obtained by SE measurement.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
D.J. Kim, Y.-M. Yu, J.W. Lee, Y.D. Choi,