The transmittance of indium-tin-oxide (ITO)/Ag/ITO multilayer electrodes under various annealing conditions was investigated. The surface morphology of the Ag layer was modified according to the annealing conditions. Depending on the surface formation of the Ag layer, the enhancement of the transmittance was differentiated into two types. Because of a change of the surface plasmon (SP) mode, connected Ag clusters with coverage of 60% resulted in transmittance enhancement over all visible wavelengths due to decreased absorption while those with coverage of 50% resulted in transmittance enhancement with a peak shift due to increased scattering by localized SP. (c) 2011 Elsevier B.V. All rights reserved.