AVS 49th International Symposium
    Thin Films Monday Sessions
       Session TF-MoA

Invited Paper TF-MoA1
Polaron Conductors with Infrared Transparency

Monday, November 4, 2002, 2:00 pm, Room C-101

Session: Transparent Conductive Coatings
Presenter: G.J. Exarhos, Pacific Northwest National Laboratory
Authors: G.J. Exarhos, Pacific Northwest National Laboratory
C.F. Windisch, Jr., Pacific Northwest National Laboratory
K.F. Ferris, Pacific Northwest National Laboratory
S.K. Sharma, University of Hawaii
Correspondent: Click to Email
Mixed transition metal spinel oxide films (AB@sub 2@O@sub 4@) deposited from solution or by means of reactive magnetron sputtering are found to exhibit resistivities on the order of milliohm-cm and optical transparency to wavelengths approaching 16 micrometers. These extraordinary properties are achieved when metal cations selected from group VIII in the periodic table are resident within the spinel lattice. Results from temperature-dependent Raman spectroscopy, Hall and Seebeck measurements, XPS, and x-ray diffracti on indicate the importance of cation disorder on the conductivity and suggest processing avenues to further tailor film properties. These include partial substitution of lithium for cations resident on the tetrahedral lattice sites and gross replacement of first row transition metal cations with those deeper in the periodic table. Electronic structure modeling approaches provide a rational path to optimizing properties in these materials. Charge transport processes in p-type spinel oxides will be contrasted with those of free-carrier driven TCO films such as cation-doped ZnO. Prospective applications of the spinel films to applications requiring high transmissivity at long wavelengths will be discussed.