NREL six-junction solar cell collections two globe records for performance

• Scientists at the National Renewable Energy Laboratory (NREL) have actually fabricated a solar cell with an efficiency of nearly 50%.

The six-junction solar cell now holds the world record for the highest solar conversion efficiency at 47.1%, which was measured under focused illumination. A variation of the same cell additionally set the efficiency record under one-sun lighting at 39.2%.

" This gadget truly demonstrates the phenomenal capacity of multijunction solar cells," stated John Geisz, a major scientist in the High-Efficiency Crystalline Photovoltaics Group at NREL as well as lead author of a new paper on the record-setting cell.

The paper, "Six-junction III-V solar cells with 47.1% conversion efficiency under 143 sunlight focus," appears in the journal Nature Energy. Geisz's co-authors are NREL scientists Ryan France, Kevin Schulte, Myles Steiner, Andrew Norman, Harvey Guthrey, Matthew Young, Tao Song, and also Thomas Moriarty.

To construct the device, NREL scientists rely upon III-V materials-- so called due to their setting on the table of elements-- that have a variety of light absorption homes. Each of the cell's six joints (the photoactive layers) is particularly developed to record light from a specific part of the solar spectrum.

The device includes about 140 total layers of different III-V materials to sustain the performance of these joints, and yet is three times narrower than a human hair. As a result of their highly efficient nature as well as the expense related to making them, III-V solar cells are most often used to power satellites, which prize III-V's unrivaled performance.

In the world, however, the six-junction solar cell is well-suited for usage in concentrator photovoltaics, said Ryan France, co-author and also a scientist in the III-V Multijunctions Group at NREL.

" One means to reduce expense is to lower the needed area," he claimed, "and you can do that by utilizing a mirror to capture the light and concentrate the light down to a point. Then you can get away with a hundredth and even a thousandth of the product, compared to a flat-plate silicon cell. You utilize a whole lot less semiconductor product by concentrating the light. An extra advantage is that the effectiveness increases as you concentrate the light."

France described the possibility for the solar cell to go beyond 50% efficiency as "in fact very achievable" yet that 100% efficiency can not be reached because of the basic restrictions imposed by thermodynamics.

Geisz claimed that presently the major research study difficulty to topping 50% efficiency is to reduce the resistive obstacles inside the cell that hinder the circulation of current. On the other hand, he notes that NREL is likewise greatly participated in reducing the price of III-V solar cells, making it possible for new markets for these extremely efficient devices.