Alta Devices reached 30.8 percent solar cell conversion efficiency earlier this month. The company developed a dual-junction thin-film PV device that builds on its previous single junction cell. The company said its a new world record for the dual junction cells.
The results were verified by the National Renewable Energy Laboratory (NREL). And while this is a record for the technology, apparently its just a (positive) speed bump in Alta Device’s PV cell evolution. “Alta Devices has been setting efficiency records since 2010,” said Chris Norris, Alta Devices’ president and CEO. While he admits that this is an important in showing the technology is ready for commercialization, he wants to see more out of the technology. “It’s also an important step toward our target of 38 percent efficient cells,” said Norris.
The new dual junction technology adds a second layer to the GaAs layer. In this case, using an Indium Gallium Phosphide (InGaP) layer as an absorber on top of the base cell. The company said InGaP uses high-energy photons (higher light bandwidth) more efficiently, the new cell can generate more electricity from the same amount of light.
The company’s thin-film Gallium Arsenide (GaAs) cells are also somewhat unique in that they are flexible, so they can be integrated with a smartphone or other device, for instance. An application the company is interested in exploring. “We are changing the way solar technology is used,” Norris said. “With our technology, enough energy can be generated from sunlight to effectively power devices in ways not previously possible. We are working with a number of customers who are designing their mobile products to increase battery life; and in some cases, we can provide enough energy to eliminate the need to plug into the electric grid,” he said.
The company also has devised a calculator to help device manufacturers understand how Alta’s cells will work for their product. The company said it’s devices could increase the battery life of an outdoor worker’s mobile device by 80 percent, or it could boost a tablet’s battery by about 60 percent.