Preparation and studies of ZnO:Al films and powders

ZnO:Al (0 - 10 at% Al) films and powders were produced using acac- modified methoxy- ethoxide precursors, obtained from Zn(C2H5)(2) and Al-4(OPri)(12). The conversion to oxide powders was monitored with TGA and DSC, and the phase development was investigated with XRD, FT- IR spectroscopy, and TEM- EDS. The gels obtained by air- hydrolysis contained ca 0.5 acac/( Zn+ Al) and a small amount of water and hydroxyls. All residual groups were removed to yield ZnO:Al by heating to ca 400degrees C. The powders obtained at 400 and 500degrees C were elementally homogeneous, and consisted of hex- ZnO: Al as ca 3 - 5 ( 10 at% Al) or 20 - 30 ( 3 at% Al) nm sized crystalline particles. Spin- coating on quartz, Si/ SiO2, and window glass, followed by heating to 500degrees C resulted in 150 - 200 nm thick films of hex- ZnO: Al. 500 nm thick films were obtained by repeating the deposition and heat- treatment twice. The films were visually very clear and the measured transmittance high over the 400 - 800 nm range ( 91 - 93% at 800 nm) for ca 300 nm thick films.