The National Renewable Energy Laboratory has developed an improved method for producing photovoltaic cells using Group III-V elements using gallium arsenide and other compounds. These materials are known for their high efficiency, but their high production costs mean Their use is limited to small satellite applications such as satellites and unmanned aerial vehicles.
NREL scientists have now found a way to improve the production of III-V batteries, a process called hydride vapor phase epitaxy (HVPE).
Aaron Ptak, a senior scientist at NREL, said that HVPE is not new. Scientists have been paying attention to it since the 1950s and 1960s. They are more willing to call it 'new, 50-year-old growth technology'. D-HVPE process The key is to use a dual chamber reactor to deposit different layers, through which they can reduce production time from one hour to about two minutes.
The team is now able to produce 25.3% efficiency GaAs cells. Although NREL acknowledges that this process will not immediately reduce costs to commercial appeal beyond satellite, military and other niche applications. But NREL Strategic Energy Kelsey Horowitz, a member of the Analytical Center's technical and economic analysis team, predicts that with technology adjustments and economies of scale, batteries made with D-HVPE can produce $0.20-0.80/W of electricity for applications such as portable/wearable solar panels. Because such intermediate markets can accept higher prices.
The researchers also acknowledge that the commercialization process will be another very expensive step. Ptak said they have a very good R&D technology and designed a test-scale reactor, but they have no way to go from A to B because this will It is a step that requires a lot of capital.
NREL is also working with Microlink Devices in the US to commercialize another ultra-light battery concept, which also uses gallium arsenide in the production process. The triple junction battery developed by Microlink has achieved 37.75% efficiency, power density. More than 3000 W/kg, it has been used in Zephyr S HALE, a high-altitude drone that uses solar energy completely, capable of performing satellite-like functions.
