NEWHAVEN, UK & MUNICH, GERMANY: Ludwig-Maximilians University (LMU) has ordered an advanced sputtering tool from Surrey NanoSystems, to support fundamental research into the fabrication of hybrid solar cells.

The tool will be used to develop production techniques that utilise precisely ordered nanowire structures as templates for organic material. Compared with conventional silicon-based solar energy systems, such new generations of hybrid solar cells have the potential to lower costs dramatically, to provide 'free' power for consumer electronics products. By building arrays of organic solar cells on a low-resistance nanowire interconnection substrate, LMU expects to dramatically increase the efficiency of the energy conversion process.

The tool will be used by researchers in LMU's Department of Physics and Centre for NanoScience. The equipment is a configuration of Surrey NanoSystems' Gamma tool, an advanced PVD (plasma vapour deposition) sputtering system that is highly optimised for both performance and versatility of use, and is widely used in R&D and pilot production applications. The tool's very high vacuum capability of 5 x 10-9 Torr, which is as much as two orders of magnitude higher than some other commercially available sputtering systems, was a key selection factor as it provides an exceptionally pure environment to aid uniform film deposition, a critical factor for the techniques being developed by LMU.

Some further special facilities for the tool have also been specified by LMU to help produce uniform aluminium films, which will then be processed to form highly ordered porous alumina membranes on various substrates, one of the fabrication approaches under research. Further support for up to four sputtering target materials will also provide the research team with the flexibility to deposit barrier layers and other inter-layer films that might be required to ensure good adherence of the solar cell's active structures.

"Structural precision is a key element of making efficient, low-loss hybrid solar cells, and LMU's research will focus heavily on this aspect," says Professor Lukas Schmidt-Mende of the LMU Department of Physics and Centre for NanoScience. "The high quality of film deposition that the Gamma tool can achieve gives us a very versatile platform to support our studies."