The cheap, stable nanocrystal solar cells developed by scientists at USC are just about four nanometers in size, meaning more than 250,000,000,000 of them can fit on the head of a pin. They exist in the form of a liquid ink which can be painted on any clear surface plus can float on a liquid solution. Scientists compare the printing of these liquid solar cells to that of a newspaper.
Researchers Richard L. Brutchey, assistant professor of chemistry at the USC Dornsife College of Letters, Arts and Sciences and USC postdoctoral researcher David H. Webber, who contributed to this project said that a new surface coating made of semiconductor cadmium selenide has been developed for the nanocrystals. International journal for inorganic chemistry Dalton Transactions has published their research as the “hot article” of the month.
Liquid nanocrystal solar cells are cheaper to fabricate than single-crystal silicon wafer solar cells but they were not as efficient in converting sunlight to electricity. Organic ligand molecules were used to keep the nanocrystals stable and prevent them from sticking. However, these same molecules insulated the crystals making them bad conductors of electricity.
Brutchey and Webber’s new synthetic ligand stabilizes the nanocrystals plus helps it transmit current with the help of tiny bridges that connect the nanocrystals. The new technology now also allows for plastic printing of the solar cells instead of glass, as no melting would occur. This will result in developing of a flexible solar panel that can be adjusted anywhere.
Although, commercial use of the technology is still years away, the pioneering research has created a new pathway for solar cell technologies.