Smart Solar Windows – New Technology Advancements

New findings from a team at the U.S. Department of Energy’s (DOE) Argonne National Laboratory mean we are one step closer to smart solar windows. This will help future buildings generate their own energy and move cities one step closer to being self-sustainable.

Smart Solar Windows – Solar Cells in Windows

Jacqui Cole, a materials scientist originally from the University of Cambridge and currently based at the Argonne National Laboratory, works with colleagues to determine the molecular structure of working solar cell electrodes. They placed them within a fully assembled device that works just like a window – these dye-sensitized solar cells are transparent and work well in conjunction with glass due to their flexibility and thin, see-through electronic circuits. 

Jacqui Cole - Working on Technology for Smart Solar Windows
Jacqui Cole – Working on Technology for Smart Solar Windows (source:

Although there have been improvements in transparent solar technology and smart windows, this is a significant technology increase as previously the interactions and unknown molecular mechanisms between the electrodes and electrolyte weren’t understood very well (i.e. how the dye interacts with the semiconductor). 

“Most previous studies have modeled the molecular function of these working electrodes without considering the electrolyte ingredients,” Cole was quoted on the ANL website. “Our work shows that these chemical ingredients can clearly influence the performance of solar cells, so we can now use this knowledge to tune the ions to increase photovoltaic efficiency.”

Research in Nanoscale earlier this year (which also came from Argonne National Laboratory) showed that certain chemical ingredients can influence the photovoltaic performance of solar cells – and a ‘modest boost’ in performance would be enough to make the cells competitive, according to Cole. She noted that manufacturing dye-sensitized solar cells is ‘very cheap’ in comparison to other solar cell tech. 

Although the organic dyes (such as the one used in this study, called MK-2) are still in lab trial stages, metal organic dyes are starting to become commercialised. For example, a building in Graz, Austria (the Science Tower) uses windows that generate renewable energy at the top sections of its tower. 

We’ll keep you updated with any news on solar windows and their real-world application. Some huge steps forward being made in this area recently! 

Silicon Alternative for Solar Cells

Researchers from the University of Cambridge in the United Kingdom and MIT, the National Renewable Energy Laboratory and Colorado School of Mines in the USA have been hard at work coming up with a silicon alternative for solar cells – given that silicon needs to have extremely high levels of purity and as such is very energy intensive to produce. After looking at options such as perovskite solar cells, the team have been using the “green element”, bismuth, in tests to create a low-cost solar cell.

Silicon Alternative for Solar Cells  – Research

The vast majority of solar cells we see on rooftops or as part of solar farms are created from silicon – a very efficient element in terms of its ability to convert light into energy, but also, as mentioned, expensive (and energy intensive) to produce.

There has been a lot of research on perovskite solar cells as a possible alternative, which we have reported on previously. Since lead is an integral part of the perovskite cell’s chemical structure, there’s still a search for a cheap, non-toxic material to create these cells – enter Bismuth.

Bismuth - A Silicon Alternative for Solar Cells
Bismuth – A Silicon Alternative for Solar Cells (source: Steve Penny, University of Cambridge via

According to ScienceDaily, Bismuth is a heavy metal like lead, but it is non toxic. Previous tests of Bismuth oxyiodide indicated that its efficiency may be too low for solar and it was also easily degraded in liquid electrolytes. However, further research has shown it may in fact be a suitable replacement for silicon in that it’s inexpensive to produce, can be very efficient in converting light into energy, and is eco-friendly.

“Bismuth oxyiodide has all the right physical property attributes for new, highly efficient light absorbers,” said co-author Professor Judith Driscoll, of the Department of Materials Science and Metallurgy. “I first thought of this compound around five years ago, but it took the highly specialised experimental and theoretical skills of a large team for us to prove that this material has real practical potential.”

We’ll see how this exciting research progresses – but in the meantime if you want to read about the study in detail you can find this journal: Strongly Enhanced Photovoltaic Performance and Defect Physics of Air-Stable Bismuth Oxyiodide (BiOI)Advanced Materials, 2017; 1702176 DOI