Black silicon could increase the efficiency of solar cells by also exploiting infrared light
He is about to end up run over, his mother saves him
Double the efficiency of solar cells, making those currently in use even better. How? Using the black. To be honest, the idea isn't brand new. Two years ago, researchers from the Technical University of Munich had proposed "black wafers" to produce a more efficient photovoltaic.
Today the researchers of the Fraunhofer Institute for Telecommunications who have thought of taking advantage of the specials black silicon solar cells designed to absorb the portion of the solar spectrum still unused today.
Solar cells currently convert i three quarters of the energy contained in the solar spectrum into electrical energy, completely losing the 'infrared spectrum'. Conversely, black silicon solar cells are specifically designed to absorb this part, doubling the overall energy efficiency.
Figures in hand, approx a quarter of the Sun's spectrum it consists of infrared radiation, which cannot be converted by normals solar cells. To overcome this limit, the German team decided to use the black silicon, a material that absorbs nearly all of the sunlight it hits, including infrared radiation, and transforms it into electrical energy.
What is it about? This material is produced by irradiating standard silicon with special femtosecond laser pulses, as explained by Dr. Stefan Kontermann, who led the research group. "This modifies the surface and integrates sulfur atoms into the silicon lattice, making the treated material black." If manufacturers were to equip their solar cells with this black silicon, they could considerably increase the efficiency of the cells, allowing them to make full use of the entire solar spectrum.
And that's what the researchers have done doubled the efficiency of black silicon in solar cells with the production of electricity from the infrared spectrum. “We discovered this by changing the shape of the laser pulse used to irradiate the silicon,” he added counterman. It was enough to introduce this novelty to obtain noteworthy results.
“We used laser pulses to modify the integrated sulfur, in order to maximize the number of electrons that can go back up, minimizing the number of those that can go back” and therefore to disperse.
The project, called Customized light pulses was one of this year's winners of the contest ‘365 Places in the Land of Ideas‘, whose awards ceremony will take place in Goslar on 11 October.
Researchers have already made prototypes of black silicon solar cells and their next step will be to try to merge these cells with commercial technology.
Francesca Mancuso
Read also:
- Black Wafer: blacken the silicon to increase the efficiency of photovoltaic panels
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