Results released by researchers at the University of Cambridge could dramatically change the face of solar cells as we know them today and there is quite a buzz being created as it seems to stand up strongly on the theoretical front.
In a nutshell, the research carried out has concentrated on what is being referred to as the recycling of sunlight. Today traditional silicon cells can capture between 11 and 15% of the total potential energy available, though recent trials in America earlier this year at the National Renewable Energy Lab set a new record which converted sunlight to electricity at the rate of 29.8% for a silicon-based cell. Irrespective of this, one of the principle problems is the inability of these cells to re-emit any energy not captured. This has been the focal point of the research in Cambridge which has shifted its attention from silicone to another material, hybrid lead halide perovskites.
This new research has discovered that unlike silicon, there is a unique property to hybrid lead halide perovskites. When solar panels using this material are struck by sunlight, just as with silicon, this light is turned into electricity. The difference though is with what happens next, and it is this which has made the results of the research so exciting. With the hybrid lead halide perovskites panel, a percentage of the electrical charge reverts back into photons, or light. The conclusion of the research is that if solar cells could be re-developed to capture and recycle these photons, there would be a substantial increase in the electrical output of photovoltaic cells.
According to Cambridge’s Felix Deschler, “It’s a massive demonstration of the quality of this material and opens the door to maximising the efficiency of solar cells. The fabrication methods that would be required to exploit this phenomenon are not complicated, and that should boost the efficiency of this technology significantly beyond what we have been able to achieve until now.”
To back up their theory, the researchers beamed a laser at a 500-nanometer-thick slice of the hybrid lead halide perovskites, upon which they discovered that the light from this laser beam was re-emitted as a high-energy output elsewhere on the material, as confirmed by lead author of the research paper, Luis Miguel Pazos Outón: “The high-energy component could not exist unless photons were being recycled.”
With these results, it will be interesting to see what effect it has on the current and near-future solar energy market. If this is going to be the way forward for both research and technological development, this will surely have to have some impact on current projections as, after all, who wants to invest heavily today in something that will be outdated tomorrow? Are silicon cells now going to become a thing of the past and confined to a corner in the Science Museum? According to PR Newswire, in 2015 the results of information gathered from 42 solar energy companies across the globe show that the solar panel industry as a whole should attain a value of $180.7 billion by 2021. What is clear today is that solar power is not just here to stay, but is taking off and market development is certain to occur. As the report asked though, “How fast?”
There has to be considerable interest in the development of new cells with greater capability to convert sunlight into energy, not just from obvious quarters, but depending on the percentage increase in efficiency, from locations where, up until now, a lack of sunlight has made them a financially unfeasible option to other forms of renewable and green energy.