When we talk about solar cells we usually and unwillingly think of crystalline silicon, which is both expensive and efficient (most of them have above 18% efficiency). Few are the cases when silicon solar cells are made from a material called “amorphous silicon” (thin film solar cells), because the efficiency of these cells is pretty low: 6 to 7 percent.
Gijs van Elzakker, from the University of Delft, Netherlands, has discovered an approach to make these relatively cheap solar cells also be efficient.
Amorphous silicon solar cells lose their efficiency during the first hours of sunlight exposure, because of the phenomenon called the Staebler-Wronski effect, which has not yet been fully explained by science. After several hours of sunlight, these types of solar cells lose about a third of their efficiency, from 10 to 7 percent.
Gijs, who got his PhD on this subject today, proposed an adaptation in the production process of amorphous solar cells to raise their efficiency. Because the silicon layer in the solar cells Gijs studies were made of silane gas (SiH4), he focused on that and proposed diluting the silane gas with hydrogen during the production process.
Adding hydrogen seemingly reduces the Staebler-Wronski effect: “We showed that the influence of the Staebler-Wronski effect can be considerably reduced in this way. If this knowledge is applied in the manufacture of this type of solar cells, a yield of 9 per cent can be expected.”
The good news is that this isn’t just pure theoretical research, because this finding had already been applied in producing solar cells by the company where Gijs works, Inventux Technologies, in Germany.
This is a somehow special case, since most of other researchers first experiment in a university lab and only a long time after they publish their findings, someone thinks about actually applying their results on their own production lines.
Let’s hope this cooperation will be fruitful enough to get the cells out on the market, so we’ll have more choices when wanting to buy a solar panel.