AVS 53rd International Symposium
    Thin Film Wednesday Sessions
       Session TF-WeM

Paper TF-WeM9
Chemical-Kinetics Analysis of In-Vacuum Cu@sub 2@Te Thermal Decomposition and Comparison to Equilibrium Vapor-Pressure Measurements

Wednesday, November 15, 2006, 10:40 am, Room 2022

Session: Thin Films for Photovoltaics and Energy Applications
Presenter: G. Teeter, National Renewable Energy Laboratory
Correspondent: Click to Email

Auger electron spectroscopy measurements of polycrystalline Cu-foil substrates exposed to elemental Te vapor at substrate temperatures below 373 K indicate that copper-telluride films are formed at the substrate surface that have a 2:1 Cu-to-Te ratio, as predicted by the Cu-Te phase diagram for a system in equilibrium. When these films are annealed above about 700 K in vacuum, Te desorbs from the substrate with zero-order kinetics. An analysis of Te desorption traces that assumes the reaction Cu@sub 2@Te(s) --> 2Cu(s) + @alpha@Te(v) + 1/2(1-@alpha@)Te@sub 2@(v) finds a thermal-decomposition activation energy of 217 ± 3 kJ/mol. These Te-desorption data are compared to the Te impingement rate calculated from Cu@sub 2@Te equilibrium vapor-pressure data@footnote 1@ from the literature and found to be in excellent agreement. This abstract is subject to government rights. This work was performed with the support of U.S. Department of Energy Contract DE-AC36-99-GO10337. @FootnoteText@ @footnote 1@B. Brunetti, V. Piacente, P. Vassallo, and A. R. Villani, Mater. Chem. Phys. 70, 263-267 (2001).