A team from the Hong Kong Polytechnic University (PolyU) have developed a novel nanostructure embedded into a semiconductor nanofibre that may reshape solar cell technology.
Most importantly, the nanocomposite corrects a key inhibitor to conductivity and can improve a wide range of applications, from batteries to solar cells and beyond.
The effectiveness of semiconductors in a wide range of applications is hampered due to a natural process where photo-generated electrons recombine with “holes” or potential electron resting spots. This results in a reduction in the moving current of electrons generated by light or external power, which in turn reduces the efficiency of the device.
PolyU’s Department of Mechanical Engineering designed a composite nanofibre that essentially provides a dedicated superhighway for electron transport, eliminating the problem of electron resting spots.
The innovation was awarded the Gold Medal with Congratulations of the Jury at the 45th International Exhibition of Inventions of Geneva in 2017.
The team inserted a highly conductive nanostructure made of graphene and carbon nanotubes into a titanium dioxide (TiO2) composite nanofiber. The graphene core facilitates efficient transport of the electrons as soon as they are generated, prior to recombining with the “holes” in the nanofiber.
The team has already tested the effectiveness of the nanocomposite in solar cells, embedding the nano-composite into the TiO2 component of dye-sensitised and perovskite-based solar cells, currently being investigated as an alternative to silicon-based solar cell technology. The new composite boosted the cells’ energy conversion rates from 40 percent to 66 percent.
The new nanocomposite has a wide range of other potential applications for semiconductor technology as well as for hydrogen generation by water splitting, biological-chemical sensors with enhanced speed and sensitivity, and lithium batteries with lower impedance and increased storage.