Comprehensive Characterization of DC Sputtered AZO Films for CIGS Photovoltaics

The characteristics of the aluminum-doped ZnO (AZO) films have been studied for copper indium gallium diselenide (Cu(In,Ga)Se-2, CIGS) solar cells. The influences of deposition parameters and film thickness on the structural, electrical, and optical properties of the AZO films deposited on the glass substrates by the d.c. magnetron sputtering process were investigated. In addition, the properties of AZO films deposited on the intrinsic ZnO (i-ZnO) coated glass substrates were also studied. Typically, the sputtered AZO films in argon atmosphere had a preferred (002) orientation. However, the films deposited under the ambient of oxygen and argon exhibited the (103) orientation and elongated grain and columnar structure. Under the given deposition conditions, the optimal AZO films of 462.5 nm in thickness possessed a low sheet resistance of 9.2 Omega/square and high optical transmittance of over 88% in the visible region. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3559456] All rights reserved.