In solar cell technology, thin films are the Holy Grail. Standard (crystalline silicon) solar cells are heavy, rigid and bulky; they’re good for bolting to the roof of your house or using as components in vast arrays covering square miles of the Mojave, discomfiting endangered desert tortoises. But that’s about it. When it comes to using them for powering small personal devices – say smart phones or scooters – they’re pretty nigh worthless.
But thin film solar cells are light, flexible – and, of course, thin. You can slap them on tablet computers, cars or ice chests, weave them into clothing, plaster the walls of your home with them like vinyl siding, and start turning sunlight into sweet, green watts.
You could, that is, if you could afford it. Which you probably can’t. Instead of common-as-dirt (literally) mono-crystalline and poly-crystalline silicon, top-of-the-line thin film solar cells use exotic and expensive compounds like aluminum gallium nitride to work their energy-generating mojo. Such so-called “III-V” materials can make the best thin-film cells ten times more expensive than your regular old silicon solar panels. Today, their use is mostly limited to satellites, and space and military applications.
Until now. As detailed in a paper published recently in Scientific Reports, Berkeley researchers have found a cost-effective way to “grow” thin-film cells. Ultimately, that could make them affordable to regular consumers, and vastly expand solar technology applications.
Ali Javey, an associate professor of electrical engineering and computer sciences and a faculty scientist at Lawrence Berkeley National Laboratory, led the group that made the breakthrough. As covered by the UC Berkeley News Center, his team induced the propagation of a III-V compound known as indium phosphide on thin metal foil sheets, a method that is quicker and cheaper than standard thin-film fabrication techniques, but maintains power production efficiency.
We’ve sent an email to Professor Javey asking him to expand on the implications of his discovery. We’ll share his insights when we receive them.