Researchers at the US Department of Energy’s National Renewable Energy Laboratory (NREL) has created a solar cell with a record efficiency of 39.5% This is the highest efficiency ever recorded for any type of cell measured in real-world conditions.
The solar cell was also tested for its potential in space, especially for powering communications satellites, which are powered by solar cells and require high cell efficiency. Under those conditions, its efficiency was 34.2%
The new solar cell is built on an architecture known as inverted metamorphic multijunction (IMM) cells. The cell has 3 components that generate electric current in response to light.
Each of those 3 junctions is built of a different material:
— gallium indium phosphide on top,
— gallium arsenide in the center, and
— gallium indium arsenide on the bottom.
As these materials specialize in various light wavelengths, this allows the cell to capture more energy from the whole light spectrum.
Also, the researchers used “quantum wells” in the middle layer, which enabled them to achieve the new record efficiency. When the researchers sandwiched a conductive layer between two other materials with a wider band gap, they were able to get the electrons confined to two dimensions, which allowed the material to capture more light in return.
Naija Philia! 
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