AVS 50th International Symposium
    Semiconductors Wednesday Sessions
       Session SC+EM-WeP

Paper SC+EM-WeP10
Growth and Characterization of Thin Films of a New Semiconductor produced by Co-Sputtering of CdTe and Al@footnote 1@

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: M. Melendez-Lira, Cinvestav-IPN, Mexico
Authors: M. Melendez-Lira, Cinvestav-IPN, Mexico
M. Zapata-Torres, CICATA-IPN, Mexico
S. Jimenez-Sandoval, Cinvestav-IPN, Mexico
M.A. Fuentes-Cabrera, Carnegie Mellon University
Correspondent: Click to Email
The atomic elements Cd, Te and Al form the compunds CdTe, CdAl@sub 2@Te@sub 4@ and Al@sub 2@Te@sub 3@. CdTe and CdAl@sub 2@Te@sub 4@ are semiconductors and their room temperature band gap are 1.5 eV and 2.0 eV, respectively. The existence of these compounds prompted us to produce a new alloy based in CdTe and Al. We have produced thin films of Cd@sub x@TeAl@sub 1-x@ by rf co-sputtering employing targets of CdTe and Al under an argon atmosphere. Aluminum content in the films was controlled by the rf power applied to the aluminum target. The chemical, structural and optical properties of the thin films have been studied by EDS, X ray diffraction, AFM, optical transmission, photoreflectance, photoluminescence and Raman spectroscopies. EDS, X-ray diffraction and Raman results shown clearly that aluminum has been incorporated in the CdTe lattice, for low aluminum content an hexagonal structure is found. For low aluminum contents transmission spectroscopy results indicate a clear blue shift in the band gap of the alloy. Photoreflectance spectroscopy indicates the presence of a direct band gap of 1.6 eV; for an aluminum content of 6%. Band gap values are discussed taking in account theoretical results obtained by first principles employing the Local Density Approximation and Generalized-Density Functional Theory approaches. @FootnoteText@ @footnote 1@Work partially supported by CONACyT-Mexico.