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

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

Undoped and Aluminium-doped Zinc oxide films have been prepared by thermal evaporation of zinc acetate (Zn(CH3COO)2

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.

Highly transparent conducting Al-doped ZnO films with good adherence and low resistivity have been prepared on polymer substrates by r. f. magnetron sputtering. Mechanically stable polycrystalline conducting ZnO: Al films having a preferred orientation with the (002).planes parallel to the substrates were deposited on polyisocyanate(PI).substrate with resistivities in the range of 4.1×10-3 to 5.110-4 π cm, with carrier densities more than 2.6×1020 cm-3 and Hall mobilities between 5.78 and 13.11 cm2 V-1 s-1. The average transmittance exceeded 80% for a 440 nm thick film deposited on polypropylene adipate (PPA).substrate in the visible spectrum. The quality of obtained films depended on substrate temperatures, sputtering power, Ar pressures and compositions of used targets during film fabrication.