This paper describes the preparation of aluminium-doped zinc oxide films by thermal evaporation of zinc acetate(Zn(CH3COO)2

Highly transparent conducting indium tin oxide(ITO)films have been prepared on glass substrates by reactively evaporating In-Sn alloy in a system with an oxygen partial pressure of (1-2)×10-4 Torr and a substrate temperature between 100 and 320℃. Mechanically stable polycrystalline conducting ITO films having a preferred orientation with the (111) planes parallel to the substrates were deposited with resistivities in the range from 1.12×10-4 to 3.07×10-4 cm, with carrier densities between 7×1020 and 1.27×1021 cm-3 and Hall mobilities between 27 and 40 cm2 V-1 S-1. The average transmittance reached 95% for a film 175 nm thick in the wavelength range of the visible spectrum. The resistivities and transmittances of the obtained films depended on the oxygen partial pressures and substrate temperatures during film fabrication.

The photoresponse of polycrystalline ZnO films generally contains both a true photoconductivity and a contribution from surface structural changes which can alter the surface conducatance via the chemisorption and photodesorption of an active ambient-gas component. The surface structural changes can increase the conductance by up to seven orders of magnitude for a 500nm thick sample when illuminated with an intensity of 4

A strong accumulation layer can be produced on the surface of polycrystalline ZnO films when the samples are exposed to ions from an ineret gas discharge in Ar or Kr. A combination of surface conductance and surface potential measurements show that an accumulation layer is induced by the adsorption of charges from the inert gas plasma which neutralizes and removes chemisorbed oxygen atoms, and this can increase the conductance by more than 6 orders of magnitude, for 500 nm thick films. Electrical neutrality in the ZnO provides the electrons for the accumulation layer, either from the ohmic contacts or the plasma. This accumulation layer can be further enhanced by illumination with UV light.

A Burstein-Moss shift has been observed in highly transparent conducting zinc oxide films prepared by ion-bean-assisted reactive deposition. The optical gaps ranged from 3.27 to 4.1 eV increase with an increase in film conductivities and carrier concentrations. Annealing over 773K reduces conductivities by several orders of magnitude and subsequently narrows the optical gaps from 3.41 to 3.24 eV. When the films are irradiated with a UV light, they exhibit some photoresponse. The observed UV photoresponse can bi interpreted using oxygen photodesorption and chemisorption at the surface