A cold method to defect-free solar cells

• Chemists on a regular basis utilize high temperatures to make things take place, however often keeping one's cool can function better. Researchers at KAUST are discovering that a low-temperature method can make better solitary crystals for usage in solar cells.

Osman M. Bakr's group in the KAUST Catalysis Facility are discovering many technologies in perovskites-- products that show fantastic possible for constructing new generations of solar cells. Novel perovskites have positive and negative ions in the same plan as the natural perovskite calcium titanate (CaTiO3). Lead halide perovskites, having lead ions as well as halide ions, such as chlorine and iodine in the perovskite mix, are drawing in wonderful interest for optoelectronic applications.

" Halide perovskite solar cells are taken into consideration the fastest growing solar innovation," says Abdullah Alsalloum, masters trainee and also co-first author of the study.

The crystals have actually previously been created at high temperatures, however these have actually created troublesome issues. Now, the KAUST team has developed a remedy, in both senses of the word, enabling better crystals to create.

Broadly, their "solvent design" approach modifies the liquid solvent in which the components of the perovskite are originally liquified, and in which they combine to build the perovskite crystals.

The specific perovskite they are developing is methylammonium lead iodide, including big methylammonium ions (CH6N+), together with lead (Pb2+) and also iodide (I-) ions. Previously, the solutions used to make the crystals needed to be kept at 120 levels Celsius, but such a high temperature hindered the optimum unification of methylammonium and also iodide ions right into the framework.

" We checked out a range of different solvents to lug the perovskite components as well as permit them to take shape," clarifies the various other co-first author of the study Bekir Turedi. "Ultimately, we located a service that might work at less than 90 degrees Celsius and produce solitary crystals that were of substantially higher quality."

The enhancement in crystal formation was matched by enhanced performance when the crystals were utilized as the light-absorbing layers in solar cells.

"We got significantly greater photovoltages, and also power conversion efficiencies approaching 22 percent, amongst the highest possible ever before reported for these perovskites," says Bakr.

The researchers recognize that their single crystals are presently also small to be taken on for business use-- an issue that presently impedes several other attempts to establish the complete capacity of perovskites in solar cells. Nonetheless, this operate at KAUST takes a vital action towards tackling this issue of dimension in addition to on further enhancements.

"The area is still in its early stage as well as one of the most exciting parts are yet ahead," Alsalloum ends.