Jülich Researchers have multi-junction solar cells from Silicon, and is reaching a record efficiency of 9.5% in the hydrogen production. The previous figure was 7.8%. But why bother? It´s Obviouse, cheaper to make and far more effective!
Hydrogen could be an important energy carrier for cars in the future. Hamburg buses already have the gas, and most recently, Toyota has brought his hydrogen car Mirai on the German market. How do they work? A fuel cell can react fueled hydrogen with ambient oxygen.
How German Researchers Producing Hydrogen?
This exothermic reaction creates water and energy for the electric motor from the exhaust drip only water vapor. A great thing for the environment so – assuming the production of hydrogen itself is environment before ending. Researchers from Jülich have taken a step forward.
The scientists want to make hydrogen with the power of the Sun. Here, silicon solar modules come into play, the solar energy is converted into chemical energy and splitting water into oxygen and hydrogen. “The special difficulty is to generate a high enough voltage. In practice approximately 1.6 V are necessary to advance the water splitting reaction”, explains Jan-Philipp Becker from the Jülich Institute of energy – and climate research. “With conventional crystalline silicon solar cells, whose photo voltage is much less than a volt, this is not to create.” So what to do?
Solar module for water splitting achieves record efficiency of 9.5%
The researchers have developed a so-called Silicon Multiple Batch Solar Module that is specially tailored to the photoelectronic water splitting.
It consists of three or four stacked one above the other cells, which in turn are composed of several layers. “Due to the multilayer structure the sunlight spectrum that spans different wavelengths can be more efficiently capture”, explains researcher Félix Urbain.
The researchers reportedly reached an efficiency of 9.5%. It’s new world record of relevant modules on silicon-based. The previous record was 7.8%. Even efficiency levels of more than 10% should be possible in the future. Urbain: “at the same time increased the voltage to 2.8 V and providing even more appropriate space to insert even less noble metals instead of more expensive Platinum catalysts such as nickel as a catalyst.”
Explaining Jülich University Researchers Technology
The researchers put on so-called thin film solar cells, which can be relatively cheap to produce. Going through silicon wafers during processing almost half of the material is lost, you can cut the layers in a vacuum on a glass or plastic substrate.
“Thin-film technology offers the advantage that it comes out as the classic etching with significantly less material, and comparatively inexpensive large scale bring up the semiconductor materials can be,” says researcher Friedhelm Finger. The next step is to scale of the solar cell on larger surfaces.