Combinatorial optimization of Al-doped ZnO films for thin-film photovoltaics

Abstract A rapid screening methodology for the development of transparent conducting oxides is presented. The methodology, based on a combination of spectrophotometry, ellipsometry and 4-point probe measurements, was used to map out the opto-electronic properties over a co-sputtered ZnO : Al 2 O 3 film deposited from separate ceramic targets of ZnO and Al 2 O 3 . Clear distributions for the carrier density, n e , and mobility, μ e , are determined as a function of wt%. Al 2 O 3 content within the film. A minimum resistivity value of 7.6 × 10 −4 Ω cm was achieved for a composition of 1.5 wt%. Al 2 O 3 .