Sam Stranks is convinced solar panels could solve our fossil-fuel dependency - if only they were more energy-efficient. "Solar could well be the solution to our energy needs and getting rid of emissions," says the Cambridge-based experimental physicist. "It's an infinite source, but expensive to harvest."
Stranks's solution: a mineral coating, called a perovskite layer, that's applied directly to a typical solar cell to boost its efficiency. "We could take a silicon solar panel with a lab record efficiency of converting sunlight to electricity of 25 per cent, add a perovskite layer, and boost the power generation by a fifth," says the 31-year-old. "For a solar cell, the maximum efficiency is around 30 per cent - but with one of these perovskite 'tandem' layers it could go up to around 50 per cent."
Much of the early work on perovskites was led by Henry Snaith, a University of Oxford professor who in 2010 co-founded a company, Oxford Photovoltaics, to commercialise the tech. The company raised more than £12m in investment in 2015. Stranks, who recently moved to the English Cambridge from the Massachusetts Institute of Technology's Organic and Nanostructured Electronics Lab, sees huge potential as the efficiency curve rises. "Hybrid perovskites over the past three years have become nearly as efficient as silicon. You get solar cells that are so light they can be suspended on a soap bubble."
The thin crystalline films are made by mixing two readily available salts, without the need for costly high-temperature processing. "They could cost half of their silicon counterparts," Stranks says. "In just three years, the efficiency has hit 21 per cent and rising - whereas conventional silicon took 30 years to get to that stage. You can inkjet print it; you can spool off reels like newsprint. And half a cup of the 'ink' would make enough perovkite solar panels to power a home." Early commercial applications, he suggests, are likely in 2017.
But it's not simply perovskites' potential in solar energy that excites Stranks, a TED Fellow. "They're also excellent light emitters - and could spawn the next generation of LEDs. What really excites me is the potential for cheap LEDs whose colour you can tune very finely.
"Now I'm researching with lasers to look at these materials - measuring the emissions by looking at fluorescence maps, made of tiny grains 1,000 nanometres in size. And that can help LEDs become more efficient. The science is there. Proving the long-term reliable operating stability is the largest challenge."
David Rowan is the editor of WIRED.
The WIRED World in 2017 is WIRED's fifth annual trends briefing, predicting what's coming next in the worlds of technology, science and design
This article was originally published by WIRED UK
