Characterization of ITO films on fluorescent borate glasses

For photovoltaic applications, the cover glass is one of the key products in solar modules. For high efficiency modules, it would be advantageous to use the glass not only as a cover but also as a down-converter. Samarium-doped borate glasses, for instance, convert the incident violet and blue part of the solar spectrum to visible red light which is more efficiently absorbed by the solar cell. The chemical composition of borate glasses consists of boron oxide as a network former and metal oxides as network modifiers. In this work, borate glasses with different network modifiers were prepared and used as substrates for the deposition of a conductive indium tin oxide (ITO) film. The deposition is done by magnetron sputtering at room temperature. To understand the electrical and optical properties of the deposited ITO films the diffusion of the glass components into the films is studied by time of flight secondary ion mass spectrometry (ToF-SIMS).