Researchers from the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have developed a six-junction III–V solar cell with a 47.1% conversion efficiency rate under 143 suns concentration.
They said that they have achieved an efficiency rate of 39.2% under one-sun illumination. The cell is based on six different photoactive layers fabricated with alloys of III–V semiconductors, which can each capture light from a specific part of the solar spectrum.
“The device contains about 140 total layers of various III-V materials to support the performance of these junctions, and yet is three times narrower than a human hair,” the scientists said.
The cell could be used in concentrator photovoltaics and has the potential to reach a 50% efficiency rate, they added. However, resistive barriers inside the cell impede the flow of current, which is the main obstacle to achieving the 50% target, they acknowledged in Six-junction III-V solar cells with 47.1% conversion efficiency under 143 suns concentration, which was published in Nature Energy this week.
In June, other NREL researchers – in partnership with scientists from the Korea Advanced Institute of Science and Technology – demonstrated a way to produce gallium arsenide (GaAs) solar cells with a reusable germanium substrate. NREL has also worked with Chicago-based Microlink Devices in the past to produce a three-junction cell with a record-setting 37.75% conversion efficiency rate.
The cost of producing solar cells based on compounds of III-V element materials – named according to the groups of the periodic table they belong to – has thus far limited such technologies to niche applications, including drones and satellites, where low weight and high efficiency are more pressing concerns than cost.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com.
“The cell could be used in concentrator photovoltaics and has the potential to reach a 50% efficiency rate, they added. However, resistive barriers inside the cell impede the flow of current, which is the main obstacle to achieving the 50% target, they acknowledged in Six-junction III-V solar cells with 47.1% conversion efficiency under 143 suns concentration, which was published in Nature Energy this week.”
Yes and over a 20 or so year period, how many of these Fresnel or ‘other’ lens concentrated solar PV is still in service? Several years back in Palm Desert, CA the Berger Foundation building had concentrating, tracking solar PV installed on parking structures around the building. Unfortunately, it did not work as planned. Now there are regular solar PV panels mounted fixed on top of these parking shades, making the power for the building. Regular solar mono crystalline solar PV panels today can “harvest” 23 to 24% of the sunlight that falls on them. Several of these same panels also have 30 year (linear) degradation warranties. I have not witnessed any concentrated solar PV that was in service for more than 5 years, then the project was abandoned. IF there was no plan by NREL to actually get to manufacture a concentrated (robust) solar PV product that could last 30 years in service, then, it’s just money spent for bragging rights and no real product at the end of the research road. If NREL wants “results” then taking the latest/greatest mono crystalline silicon solar PV cells and creating a “spray on” process that would make a long lasting tandem wide bandgap solar PV cell in the 30% to 35% range, now you’re spending tax monies wisely.
We can’t wait !!