TEXTURED ALUMINUM-DOPED ZINC-OXIDE THIN-FILMS FROM ATMOSPHERIC-PRESSURE CHEMICAL-VAPOR DEPOSITION

Aluminum-doped zinc oxide films have been deposited on soda lime glass substrates from diethyl zinc, triethyl aluminum, and ethanol by atmospheric pressure chemical-vapor deposition in the temperature range 367-444-degrees-C. Film roughness was controlled by the deposition temperature and the dopant concentration. The films have resistivities as low as 3.0 x 10(-4) OMEGA cm, infrared reflectances close to 90%, visible transmissions of 85%, and visible absorptions of 5.0% for a sheet resistance of 4.0 OMEGA/square. The aluminum concentration within doped films measured by electron microprobe is between 0.3 and 1.2 at. %. The electron concentration determined from Hall coefficient measurements is between 2.0 x 10(20) and 8.0 x 10(20) cm-3, which is in agreement with the estimates from the plasma wavelength. The Hall mobility, obtained from the measured Hall coefficient and dc resistivity, is between 10.0 and 35.0 cm2/V s. Over 90% of the aluminum atoms in the film are electrically active as electron donors. Scanning electron microscopy and x-ray diffraction show that the films are crystalline with disklike structures of diameter 100-1000 nm and height 30-60 nm. The films have the desired electrical and optical properties for applications in solar cell technology and energy efficient windows.