Stanford University scientists design disulfide solar cells based on tungsten diselenide

2024-08-27 

A team of researchers led by Stanford University has developed a new manufacturing process that allows for scalable manufacturing of transition metal dichalcogenides (TMDs) solar cells, bringing them closer to commercial production.

WSe2 thin film for new solar cell concepts

TMD is a two-dimensional material with excellent semiconductor properties and high light absorption coefficient. This makes them suitable for producing semi transparent and flexible solar cells, and has the potential to be applied in aerospace, construction, electric vehicles, and wearable electronic products, where lightweight, high power to weight ratio, and flexibility are highly needed.

The corresponding author of the study, Koosha Nassiri Nazif, stated, “We have developed a scalable and suitable method for large-scale production of tungsten diselenide (WSe2) films at the photovoltaic and wafer levels. The films have a layered van der Waals structure and excellent properties, including a carrier lifetime of up to 144 nanoseconds, which is more than 14 times higher than any other large-area TMD film previously demonstrated.

The team has designed a sputtering multi-layer WSe2 film with a thickness of 15-30 nanometers, which can be applied to 150mm wafers through selenization processes based on 900 ° C solid source selenium (SS Se) or 650 ° C low thermal budget hydrogen selenium (H2Se) precursors. The band gap of the obtained WSe2 film is 1.2 eV to 1.3 eV, which scientists describe as an almost ideal band gap for solar energy harvesting.

According to reports, compared to previous reports on selenization, the film exhibits superior characteristics with a smooth and uniform surface. Researchers have stated that by improving contact and doping, the efficiency of optimized solar cell designs can reach 22.3%.