Feb 28 (Renewables Now) - Scientists at the University of Toronto (U of T) have developed a chemical reaction allowing them to make the electron selective layer (ESL) in perovskite solar cells at much lower temperatures than previously required.
“The most effective materials for making ESLs start as a powder and have to be baked at high temperatures above 500 degrees Celsius,” explains University Professor Ted Sargent. Placing that on top of flexible plastic or on a fully fabricated silicon cell will lead to melting.
Now the U of T team’ chemical reaction allows for the growing of an ESL made of nanoparticles in solution, directly on top of the electrode. The process always stays below 150 degrees Celsius.
Reducing the temperature is a key step on the road to the easy and inexpensive printing of solar cells. With perovskite, the raw materials can be mixed into a liquid, forming a kind of “ink”, that could then be printed onto glass, plastic or other materials using a simple inkjet printing process. Up to now the difficulty of manufacturing a good ESL has been one of the main challenges in that area.
“Perovskite solar cells can enable us to use techniques already established in the printing industry to produce solar cells at very low cost. Potentially, perovskites and silicon cells can be married to improve efficiency further but only with advances in low-temperature processes,” says Sargent.