We study the optical and electrical properties of silver films with a gradedthickness obtained through metallic evaporation in vacuum on a tilted substrateto evaluate their use as semitransparent electrical contacts. We measure theirellipsometric coefficients, optical transmissions and electrical conductivityfor different widths, and we employ an efficient recursive method to calculatetheir macroscopic dielectric function, their optical properties and theirmicroscopic electric fields. The topology of very thin films corresponds todisconnected islands, while very wide films are simply connected. Forintermediate widths the film becomes semicontinuous, multiply connected, andits microscopic electric field develops hotspots at optical resonances whichappear near the percolation threshold of the conducting phase, yielding largeohmic losses that increase the absorptance above that of a correspondinghomogeneous film. Optimizing the thickness of the film to maximize itstransmittance above the percolation threshold of the conductive phase weobtained a film with transmittance T = 0.41 and a sheet resistance$R_{\square}^{\mathrm{max}}\approx2.7\Omega$. We also analyze the observedemission frequency shift of porous silicon electroluminescent devices when Agfilms are used as solid electrical contacts in replacement of electrolyticones.
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