In the first chapter of this work I demonstrate the structure and operation principles of solar cells then I present a few possible applications. After that, I explain the layer structure of thin film CIGS solar cells paying special attention to the transparent top contact layer. I present the methods of layer deposition with special emphasis on the Atomic Layer Deposition (ALD) technology. The following part of my work deals with the characterization methods which we use to describe the structure of the layers. These are: scanning electron microscopy, X-ray diffraction, ellipsometry and the van der Pauw measurement.
In the experimental chapter of my work I deposit doped ZnO layers onto soda lime glass and Si wafer substrates at different temperatures and with different Al doping, by using ALD technology. The purpose of the experiments was to characterize the thickness, electrical conductivity and crystalline structure of the layers as a function of deposition parameters. Furthermore I investigated the change of carrier concentration and mobility after annealing. The results improve our knowledge to find an optimal technology to deposit transparent solar cell contacts.