Photovoltaic solar cells made of crystalline silicon are widely used today, but they are difficult to make translucent. Perovskites are hybrid organic-inorganic photovoltaic materials, which are cheap to produce and easy to manufacture. Technology has increased the efficiency of perovskites rapidly in recent years, to the point that they are now at the level of silicon technologies.
However, perovskite has always presented a major problem when in its regular form, with it being unstable when in contact with water or even normal humidity. Perovskite is named for the Russian mineralogist Lev Perovski and can deteriorate within a matter of minutes or hours, reports AZO Cleantech.
And that particular problem of breaking down in the presence of moisture has apparently been overcome by a team of researchers from Lund University in Sweden and from Fudan University in China, reports Science Daily.
It seems that while testing two different water-repellent surfaces of perovskite sheets they had developed, they found that one of the sheets gave much better results than the other, and they wanted to know why. So they conducted more experiments and were they ever surprised.
The research team discovered that their perovskite sheets had a unique ability – the structure of the sheets was self-organising and stood on their edge. This unusual ability greatly increased the efficiency of the perovskite sheets.
“We have succeeded in producing thin sheets with a water-repelling surface, making the whole construction much more stable. In addition, we have succeeded in orienting the sheets so as to obtain acceptable solar cells, with an efficiency of ten percent,” says Tönu Pullerits, professor of chemical physics at Lund University.
Basically, the self-organising structure of the sheets allows electrons to move freely between the contacts, greatly increasing the efficiency of converting solar energy to electricity. Pullerits sees the result as an important step on the way to constructing stable and efficient solar cells out of perovskite. “Stability is a key issue for solar cells,” he says.
This interesting study, Tailoring Organic Cation of 2D Air-Stable Organometal Halide Perovskites for Highly Efficient Planar Solar Cells, was published in the online journal Advanced Energy Materials on May 16, 2017.
