Synthesis and optelectronic characterization of gallium doped zinc oxide transparent electrodes

In this work we report on pulsed laser deposition of gallium-doped zinc oxide (ZnO:Ga) transparent-conducting thin films grown on glass at different substrate temperatures, A widening in the optical bandgap and a good gallium-doping efficiency were observed in the films when the substrate temperature was raised from 150 degrees C to 300 degrees C, as determined from optical and electrical measurements. X-ray diffraction measurements revealed that the films grow preferentially oriented in the [002] crystallographic direction of the ZnO grains. The crystallinity of the films was also found to be strongly dependent on the substrate deposition temperature. The ZnO:Ga transparent films had excellent transmittance (85%) in the visible spectrum and a low electrical resistivity value (7 x 10(-4) Omega cm) in 200 nm thickness samples deposited on glass by laser ablation at 300 degrees C.