Its efficiency can already compete with that of silicon-based solar modules.
Thin victories
Researchers at the University of Oxford say they have developed a new “multi-junction” technique to create a solar material so thin it can be printed directly onto the surface of everyday objects, from cars and smartphones to backpacks.
The results have not yet been published, but the researchers say their material, which is just one micrometer thick, has already achieved energy efficiency of over 27 percent. That’s five percent more efficient than the silicon-based cells used in conventional solar panels and exceeds the efficiency achieved by other research into ultra-thin solar materials.
“In just five years of experimenting with our stacked or multiple junction approach, we have increased energy conversion efficiency from around six percent to over 27 percent, close to the limits of what single-layer photovoltaics can achieve today,” said Shuaifeng Hu, a physics graduate at the University of Oxford who was involved in the research, in a statement.
“We are convinced that this approach could, over time, lead to significantly higher efficiencies of photovoltaic systems of over 45 percent.”
Solar energy, everywhere
The ultra-thin solar cells use a family of materials called perovskites, arranged in multiple light-absorbing layers to increase the range of sunlight they can absorb.
100 times thinner than a human hair, according to CNNAt 150 times thinner than the silicon wafers used in conventional solar panels, it is more of a coating than a hard material, which brings a number of advantages: it is flexible, can be easily applied to existing objects, and does not require huge amounts of exclusive space to do its job.
For example, instead of building an entire field of solar modules, the capacity could be distributed across many small areas – the idea being not to replace solar parks, but to support them.
“We can imagine applying perovskite coatings to broader types of surfaces to generate cheap solar energy, such as on car roofs and building roofs and even on the back of mobile phones,” said Oxford physicist Junke Wang in the statement.
“If more solar energy can be generated in this way, in the long term it is likely that we will have to use fewer silicon modules or build more and more solar parks,” he added.
However, perovskites are not perfect: they are not considered particularly robust and can be destroyed over time by moisture, oxygen and – counterproductively – light. However, the efficiency gains achieved here are nothing to sneeze at – and we may be on the cusp of a solar future in which the technology is even more ubiquitous than we once imagined.
More on the topic of solar: California now has so much solar energy that electricity prices become negative during the day
