Research group light scattering contacts
We investigate and develop transparent or reflective contact layers for silicon thin-film solar cells as well as concepts for effective light trapping in the absorber layer. These contacts are based on metal oxides (transparent conductive oxides, TCO) like zinc oxide or metals like silver. Apart from their functionality as electrical contact these layers act as source for light scattering and light trapping. Therefore, these contacts contribute significantly to the conversion efficiency of the solar cell. Materials, sputter deposition as well as texturization processes are developed in cooperation with research and industry partners. The contacts composed of single or multi layers and the texturization of the TCOs are optimized with respect to their electro-optical and structural properties for effective light trapping. We investigate the chemical etching of ZnO and alternative routes to achieve surface textures. The optimization closely interacts with the development of solar cells or modules to achieve well working devices. Characterization of the contacts as well as identification of ideal TCO textures and light scattering are supported by optical simulations.