Better Spray On Solar Cells With Perovskite

According to the U.S. National Renewable Energy Laboratory, more solar energy from the sun bathes the earth in one hour than is used by everyone in the world in a whole year.

Currently, the most common technologies for capturing this free energy are solar panels and solar thermal systems, both of which require complex manufacturing techniques.

One of the promising fields of solar science is in harnessing organic photovoltaic semiconductors, which can be sprayed or rolled out over large areas like the walls and windows of buildings – effectively turning theses surfaces into working power plants. They are less expensive and require much less energy to manufacture than silicon-based solar material.

Recently it has been reported that perovskite, a superconducting organometal capable of capturing solar energy at very impressive levels, could boost efficiency returns in spray-on solar cells and lower the cost of solar power to just 10 cents per watt.

A team at the University of Sheffield say they have combined the two technologies and perfected a technique for fabricating spray-on perovskite solar cells.

The researchers replaced the key light-absorbing layer on each organic solar cell with a layer of spray-on perovskite, which boosted the efficiency of the device.

“The best certified efficiencies from organic solar cells are around 10 per cent,” said lead researcher Professor David Lidzey.

“Perovskite cells now have efficiencies of up to 19 per cent. This is not so far behind that of silicon at 25 per cent – the material that dominates the world-wide solar market. Remarkably, this class of material offers the potential to combine the high performance of mature solar cell technologies with the low embedded energy costs of production of organic photovoltaics.””

The Sheffield team used a spray on process similar to applying paint to cars and large-scale printing which wastes very little of the perovskite material.

Professor Lidzey said: “This study advances existing work where the perovskite layer has been deposited from solution using laboratory scale techniques. It’s a significant step towards efficient, low-cost solar cell devices made using high volume roll-to-roll processing methods.”

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