Photovoltaics (PV) and the solar energy industry as whole is in constant pursuit of maximum efficiency. It will be no surprise that the material science community is at the forefront of developing the platforms for this perpetual technological advancement.
Recently there has been a huge amount of press, PR and talk about a variety of materials, including Graphene and how the revolutionary characteristics of these 'wonder' materials might improve all manner of different technologies and industries.
Even though the potential for graphene to transform the way we harness the suns rays to generate electricity is huge, there are also many other technological advancements in Photovoltaics that also have the potential to dramatically improve both the sustainability and efficiency of future Solar cell technologies.
Innovnano’s nanostructured AZO sputtering targets; the sustainable replacement for ITO.
Solar Photovoltaics work on the ability to capture (harness) as much of the suns light as possible to transform this into useful energy, in the form of electricity. Therefore, by their very nature photovoltaics rely on materials that offer excellent transparency and conductive properties.
Photovoltaics employ optically transparent and electrically conductive thin films to allow the sun's light energy to pass through to the active material within the solar cell which generates an electrical current. The efficiency of this transparent conducting film (TCF) is a fundamental factor in the efficiency of a PV cell and as such the development of more sustainable and efficient TCFs is a key focus of solar research and development worldwide.
Innovnano, a manufacturer of high performance ceramic powders is at the forefront of developing materials to help improve the efficiency and sustainability of solar photovoltaic cells. Recently Innovnano has published more information about their latest nanostructured Aluminium-doped Zinc Oxide (AZO) which has been specifically designed to help improve thin-film solar cell efficiency.
Innovnano's AZO sputtering target technology, exhibits the ideal characteristics for the development of next generation, advanced performance TCO films, a key area of interest for many researchers and scientists worldwide. Naturally the material science community is excited to see what the new technology can do.
Why is a more efficient TCO Important?
TCFs for photovoltaic applications are typically fabricated out of either organic or inorganic materials. There is a great deal of research into the best and most efficient thin film technology and Innovnano's nanostructured AZO technology has been designed to advance research in the inorganic TCO sector.
The new nanostructured Aluminium-doped Zinc Oxide (AZO) material offers the potential to develop TCOs on a much larger, industrial scale. This will help improve both the sustainable characteristics and efficiency of solar photovoltaics that employ inorganic technology.
Traditional inorganic films are typically made of a layer of TCO (Transparent Conducting Oxide) fabricated from Indium Tin Oxide (ITO), which as you may guess from the fact that Indium is quite rare are often therefore, expensive. Not only does Innovanano's AZO offer a viable solution at a much lower cost than ITO, it is also more adhesive and can be processed easily at low temperatures for flexible thin film solar cell applications.
Employing a patented Emulsion Detonation Synthesis Process (EDS), Innovnano's AZO products are extremely pure, nanostructured Powders that offer researchers a higher density and chemical homogeneity when compared with typical microstructured AZO ceramic powders.
Another key factor of efficiency of TCO films is the ability to reduce the amount of defect and grain boundaries within the film. Innovnano's AZO can be sintered at far lower temperatures to produce sputtering targets that portray minimal grain growth, defects and mirrored characteristics. The ability to sinter at lower temperatures also creates a more uniform distribution of Al within the Zinc oxide matrix resulting in a more stable and consistent thin film, perfect for research and development applications. As Patrick Isherwood a researcher at the CREST Laboratory commented:
“These AZO targets are without doubt the easiest to use of any AZO target we’ve worked with, and consistently produce top quality thin films with the electrical and optical properties we need for solar cell applications”.
Supplied in 50, 75, 150mm diameter sputtering targets, Innovnano's AZO products make it possible to consistently produce high performance TCOs which have been shown to exhibit over 80% transmittance in the visible range. Coupled with extremely good electrical conductivity, this makes it a very attractive product for the development of the next generation of Photovoltaic cells.
Joấo Calado, Innovnano’s Technical Director, highlights the potential of their AZO sputtering targets:
“At Innovnano, we’re working to enable research and development teams to produce working prototypes of the next wave of environmentally-sustainable, super-efficient photovoltaic cells. The beneficial characteristics of our nanostructured AZO powder are inherent to our production method, ensuring that we can produce the sputtering targets that researchers need to produce ultra-transparent conducting oxides”.
Innovanano is working hard to push the boundaries of efficiency and sustainability in the next generation of Photovoltaic materials and designs. The new Nanostructured AZO product offers researchers the ability to produce TCOs with a highly consistent homogeneous grain structure and high transmittance of visible and near IR wavelengths.
Ultimately this will allow researchers to design photovotaics with maximum energy capture to produce the most efficient and sustainable solar cells of the future.