VATIS UPDATE Article

A University of Toronto Faculty of Applied Science & Engineering innovation could make printing solar cells as easy and inexpensive as printing a newspaper. Dr. Hairen Tan and his team have cleared a critical manufacturing hurdle in the development of a relatively new class of solar devices called perovskite solar cells. This alternative solar technology could lead to low-cost, printable solar panels capable of turning nearly any surface into a power generator.

Tan and his colleagues developed a new chemical reaction than enables them to grow an ESL made of nanoparticles in solution, directly on top of the electrode. While heat is still required, the process always stays below 150 degrees C, much lower than the melting point of many plastics. The new nanoparticles are coated with a layer of chlorine atoms, which helps them bind to the perovskite layer on top – this strong binding allows for efficient extraction of electrons. In a paper recently published in Science, Tan and his colleagues report the efficiency of solar cells made using the new method at 20.1 per cent.

“This is the best ever reported for low-temperature processing techniques,” said Tan. He adds that perovskite solar cells using the older, high-temperature method are only marginally better at 22.1 per cent, and even the best silicon solar cells can only reach 26.3 per cent. Another advantage is stability.