Brand-new pathways for tin-monosulfide PV

• Scientists in Japan have established a new procedure for the manufacture of crystalline tin monosulfide (SnS). By facilitating the development of crystals measuring up to 24mm in size, the procedure can aid conquer several of the challenges to pressing higher efficiencies out of this cheap, plentiful product.

New thin film materials have an essential function to play in solar modern technology's future. Though many have much to go before producing business interest, using potential for combination in flexible or semi-transparent tools, as well as layers in a multi-junction 'tandem' tool even more into the future. And also with issues over material intake in solar ending up being ever before extra famous, finding alternatives to the in some cases rare, expensive and also toxic used in today's thin film PV technologies is an additional lasting objective.

Though called a cheap, abundant material with appealing qualities for use in solar cells, tin monosulfide (SnS) has proved a challenging material to work with, and also researchers have until now had a hard time to achieve conversion performances much better than 5% with this product, and also rate of interest from the research community has actually lagged behind that of kesterite, or copper-zinc-tin, solar cells.

The obstacle, according to researchers at Japan's Tohoku University, depends on creating n-type SnS, essential to develop a joint with the a lot easier to make p-type matching. Provided its theoretical potential for solar cell performance beyond 30%, in addition to the reality that tin already flaunts an innovative supply chain, and also fully grown industrial to create tin-based thin films currently exist, overcoming this difficulty is an attractive possibility for scientists.

Molten change

A group of researchers at Tohoku went about creating a procedure to grow SnS crystalline from a molten tin change. The team found that adding halogen components (in this case chlorine and bromine) to the flux resulted in the development of much larger as well as thicker crystals-- they gauged a maximum of 16mm diameter as well as 0.7 mm density for chlorine-doped SnS, as well as 24mm diameter, 1mm density with bromine.

Image: Tohoku University

The development procedure is defined in the paper Growth of Large Single Crystals of n-Type SnS from Halogen-Added SnS Flux, published in the journal Crystal Growth and also Design. The team went on to determine the electric features of the thin film, observing encouraging electrical conductivity attributes as well as validating the product's n-type conductivity.

"The large solitary crystals of n-type SnSn acquired in this work would certainly make it possible for the manufacture of p-n homojunction SnS solar cells via the deposition of p-type SnS thin films," the paper concludes.