Electrochemical deposition of smooth and homogeneously mesoporous ZnO films from propylene carbonate electrolytes

Nanoporous ZnO films have been electrodeposited on transparent conductive supports using an electrolyte of LiNO3 and ZnCl2 in propylene carbonate (PC). Varying the salt concentrations, water content and voltage gives wide control over the morphology and porosity of the films. For 0.15 M LiNO3 and 0.05 M ZnCl, the resulting ZnO films consist of vertically oriented, semicontinuous columns between 10 and 30 nm in diam. This morphology has proven to be very useful in constructing solid-state dye-sensitized solar cells. In this paper, we give details concerning the effects of water content, oxygen content, and counterions on the electrodeposition of ZnO from PC. Transformations in the films caused by heating and degradation of the deposition solution with time are also discussed. (C) 2001 The Electrochemical Society. [DOI: 10.1149/1.1377899] All rights reserved.