Chinese-American Ph.D. student won a new method for manufacturing solar cell light film

According to the US “Sing Tao Daily” report, perovskite (Perovskite) solar cells can be a cheap and effective alternative to silicon crystalline solar cells. A new technology has the potential to mass produce thinner perovskite films at room temperature without sacrificing quality. Thin-film perovskite solar cells can be used to produce power-generated stained glass windows. A research led by a doctoral student of Chinese origin at Brown University has found new ways to make light-absorbing perovskite films for solar cells.

This new method utilizes room-temperature solvent soaking to produce perovskite crystals that replace the heating method used to crystallize current crystals. The study published in the "Journal of Materials Chemistry" of the Royal Society of Chemical Technology shows that this technology can produce high-quality crystalline thin films with a high degree of precision and control, and may be the way forward for the mass production of perovskite solar cells.

The perovskite film is a good light-absorbing material and the production cost is lower than that of the silicon chips used in general solar cells. In just a few years, the photovoltaic efficiency of perovskite batteries has grown by leaps and bounds. The first perovskite battery that appeared in 2009 can only have an efficiency of about 4%, which is far lower than 25% of the standard silicon cell. But last year, perovskite batteries have proven to have more than 20% efficiency. The rapid improvement in performance has huge potential. Researchers are scrambling to start using perovskite batteries for commercial products.

There are different ways to make this film, but almost all of it is to use heat. Perovskite precursor chemicals are dissolved in a liquid and then coated on a substrate. After heating to remove the solution, the perovskite crystals left on the substrate form a thin film.

Yuanyuan Zhou of Brown University's Padture Lab is looking for ways to make perovskite films that do not need to be heated. Think of solution-solution extraction.

Using Zhou's method, the perovskite precursor was first dissolved in a solvent called NMP and coated on the substrate. Subsequent to the heating, the substrate was immersed in a second solvent, diethyl ether (DEE). Selectively pump away the NMP solvent.