Conductivity enhancement in transparent ZnO films via Al-doping produced by CW-CO2 laser-induced evaporation

Highly conductive transparent aluminium-doped ZnO (ZnO:Al) films were successfully deposited by CW-CO2 laser-induced evaporation. Optimisation of evaporation parameters was based on laser power, substrate temperature, O-2 partial pressure in the vacuum chamber and amount of Al in the ZnO source pellet. ZnO:Al films with an electrical resistivity as low as 6.6 x 10(-2) Ohm.cm and an optical transmission of 80% at 500 nm were obtained at laser power of 15 W, substrate temperature of about 200 degrees C, O-2 partial pressure of 6-7 x 10(-4) Torr and 5wt.% Al. Conductivity of ZnO films can be increased one order via Al-doping in ZnO films. The films obtained by laser-induced evaporation have compared quite favorably with the high quality films obtained by sputtering. (C) 1997 Elsevier Science S.A.