Polycristalline CdTe Thin Films Solar Cells

We report the state of the art of the second generation of solar cells, based on CdTe thin film technology. This type of cells reached on laboratory scale, photovoltaic energy conversion efficiencies of about 16.5% higher than those obtained with the bulk materials. In particular, we describe the materials, the layers sequence, the characteristic deposition techniques and the devices that are realized by adopting this semiconductor as absorber material. Particular emphasis will be placed on major innovations that have made possible to achieve high efficiencies with polycrystalline materials by showing how the thin-film technology is mature enough to be easily transferred to industrial production. We will focus our attention on a technological project, completely developed in Italy, with the aim to transfer the CdTe/CdS polycrystalline thin film photovoltaic module process to an industrial production.