New Multi-band semi-conductors to make solar cells more efficient
Scientist at Lawrence Berkeley National Laboratory (LBNL) have created a semiconductor material with three energy bands. This means that not only these cells will be cheaper but more efficient.
They will not only be able to trap more low-energy photons but will also be able to convert more sunlight into electricity. Conventional solar cells respond to a very narrow spectrum of sunlight making them highly inefficient as photons with lower energy pass right through them.
The researchers found that on introducing a few atoms of oxygen into a zinc-manganese-tellurium (ZnMnTe) alloy splits the compound semiconductor's conduction band into two parts. Similarly, adding nitrogen to a semiconductor such as gallium arsenide phosphide will also give a multi-band semiconductor.
The new semiconductor material can capture these low-energy photons for electricity, which could make solar cells with efficiencies of around 45 percent, compared with 25 percent for conventional cells that use a single semiconductor and 39 percent for cells with layers of mixed semiconductors.
However there is no word on when this technology will be commercially available in the market.
Via: Technologyreview
