Cheap perovskite boosts commercial solar cell energy conversion by 20%

UCLA created a double layer solar cell by spraying a thin layer of perovskite onto a commercially available solar cell. The solar cell that forms the bottom layer of the device is made of a compound of copper, indium, gallium and selenide, or CIGS. The new cell converts 22.4% of the incoming energy from the sun.
The performance was confirmed in independent tests at the U.S. Department of Energy’s National Renewable Energy Laboratory.
The cell’s CIGS base layer, which is about 2 microns (or two-thousandths of a millimeter) thick, absorbs sunlight and generates energy at a rate of 18.7 percent efficiency on its own, but adding the 1 micron-thick perovskite layer improves its efficiency — much like how adding a turbocharger to a car engine can improve its performance. The two layers are joined by a nanoscale interface that the UCLA researchers designed; the interface helps give the device higher voltage, which increases the amount of power it can export.
And the entire assembly sits on a glass substrate that’s about 2 millimeters thick.
“Our technology boosted the existing CIGS solar cell performance by nearly 20 percent from its original performance,” Yang said. “That means a 20 percent reduction in energy costs.”
He added that devices using the two-layer design could eventually approach 30 percent power conversion efficiency. That will be the research group’s next goal.