AVS 51st International Symposium
    Thin Films Monday Sessions
       Session TF-MoP

Paper TF-MoP2
(CdTe)@sub 1-x@Al@sub x@ Thin Films Grown by RF Co-sputtering for Photovoltaic Applications@footnote 1@

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: M. Meléndez-Lira, Cinvestav-IPN, México
Authors: L.A. Estrada -Domínguez, ESFM-IPN, México
M. Meléndez-Lira, Cinvestav-IPN, México
M. Becerril-Silva, Cinvestav-IPN, México
M. Zapata-Torres, CICATA-IPN, México
S.J. Jiménez-Sandoval, Cinvestav-IPN, México
Correspondent: Click to Email
Solar cells based on the heterostructure CdS/CdTe have been under a continuous development and there are commercial devices available. However, still there are problems limiting the efficiency predicted theoretically. Between the limiting factors, we found the difference in crystal structure between de CdTe (cubic) and CdS( hexagonal) and the inherent production of defects at the CdS/CdTe interface. Besides the interface problems, there are some difficulties to doping CdTe as p-type . We have produced (CdTe)@sub 1-x@Al@sub x@ films by RF co-sputtering employing CdTe and Al targets under an Ar atmosphere. Al content was controlled by the RF power of the Al magnetron. An increase in the bandgap depending on the Al content was found and values up to 1.61 eV for 6% of Al content were obtained . The samples presented hexagonal structure with lattice parameters values depending on the Al content, as determined by EDX. Raman spectroscopy clearly shows the incorporation of aluminium into the CdTe lattice. We will present in this work the results of an electrical transport characterization obtained by the Van deer Paw resistivity method and Hall effect measurements. We have found that for some growth conditions we can produce low resistivity samples with p-type conductivity. The results of the electrical characterization will be correlated with studies of the spectral photoresponse, optical and structural characterization carried out on the (CdTe)@sub 1-x@Al@sub x@ films. We propose a (CdTe)@sub 1-x@Al@sub x@ film as a solution for some of the problems presented in photovoltaics devices based on the CdS/CdTe heteroestructure using it to replace the CdTe film. @FootnoteText@ @footnote 1@: work partially supported by CONACyT-México.