Scientists check out the role of surface area texturing in perovskite-silicon tandem cells

• Nano-textured surface areas are an interesting strategy for maximizing the optical qualities for monolithic perovskite/silicon tandem solar cells. Researchers from Germany's Helmholtz-Zentrum Berlin (HZB) have actually checked out the growth of different textures of silicon surface areas making use of different industrial additives as well as their efficiency in silicon heterojunction (SHJ) and also SHJ-- perovskite tandem solar cells.

The group done optical and electric characterization as well as located that nano-textured surface areas can take on standard textured surface areas, producing higher ordinary efficiencies in solitary joints. Additionally, their compatibility with solution-processed perovskite top cells was demonstrated in the recent study, producing a perovskite/silicon tandem solar cell effectiveness of > 28% on a bottom cell with nano-texture on both sides.

In silicon wafer and also cell production, the surface area of the wafer is typically given a texture of tiny pyramid shapes, which offer to decrease reflection and also trap more light in the cell. This texture is normally accomplished by dipping wafers into fluid chemicals, which remove some silicon as well as leave behind the textured surface. Various other processes, typically entailing shooting a plasma compound at the silicon surface, are known to use better control over the size and harmony of the bumps that compose the texture. Most suppliers, however, see these as too complex and also pricey, with only a limited benefit compared to the wet chemical process.

Positioning a perovskite solar cell ahead, nevertheless, adds new demands for the silicon surface area. Much of the achievements made so far with tandem cells have been done on a silicon cell without texturing, which makes it simpler to incorporate the perovskite but could be seen as a lost possibility for the silicon cell effectiveness. The group at HZB investigated several of the extra complex texturing procedures and found that the boosted control as well as smaller surface area textures they manage might solve the perovskite assimilation challenge, and even be of passion again for single-junction silicon cells.

" For tandem cells, an attire and also small-sized Si texture is important in order to have the ability to wet process the perovskite top cell," the group clarified. "We revealed that sub-micrometer sized random pyramids by an adjusted wet etching procedure are an intriguing technique not just for such tandem solar cells but also for SHJ solitary junction solar cells."

In their paper, the scientists explained experiments with different etching options. They discovered that varying the composition of the service allowed them to manage the size of the pyramids on the surface, maintaining the desirable anti-reflective features of the engraved surface area, while making it less complicated to place the perovskite layer on the top.

"All JV specifications were comparable or perhaps somewhat better as compared to those of cells with our conventional micro-texture," said the team.

Making use of these new nano-texturing procedures, the group showed a 28.9% effective tandem cell. The researchers stated they are confident that such a process could be adopted at scale.

"We expect that the here and now processes will certainly be easy to be applied in commercial manufacturing and, for this reason, will certainly add to the growth of a production process for highly effective tandem solar cells," they stated.