Researchers have developed light sensitive particles that allow for cheaper, lighter, and more flexible power sources.
A team of researchers at the University of Toronto have developed a new form of solid and stable light sensitive nanoparticles called colloidal quantum dots that can potentially pave the way for solar cells that are cheaper, lighter and more flexible than the solar cells existing today.
The researchers are from the university’s Edward S. Rogers Sr. Department of Electrical and Computer Engineering and are led by post-doctoral researcher Zhijun Ning and Professor Ted Sargent. The study was recently published on Nature Materials.
The team of researchers was able to create a material that does not lose its electrons when exposed to air. The effectiveness of the colloidal quantum dots to absorb sunlight depends on two types of semiconductors, the n-type which has a lot of electrons, and the p-type, which has only a slight amount of electrons. N-type materials bind to oxygen atoms and turn into p-type when exposed to the air. The research team was able to develop an n-type material that keeps its electrons when exposed to air.
A stable combination of layers of n-type and p-type materials increases the effectiveness of light absorption and can potentially be useful in creating new devices that work with light and electricity. The colloidal quantum dots could also mean better sensors, infrared lasers, infrared light emitting diodes, and even satellites.
The new hybrid n- and p-type material developed by Ning and her team achieved an eight percent solar power conversion efficiency.
In a news release, Ning said,
This is a material innovation, that’s the first part, and with this new material we can build new device structures. Iodide is almost a perfect ligand for these quantum solar cells with both high efficiency and air stability—no one has shown that before.
The colloidal quantum dots can be added to paints and inks or printed onto surfaces, and maybe usher in a new world where solar cells can simply be printed or painted on surfaces and replace complex installation methods.
The project was conducted in collaboration with Dalhousie University, King Abdullah University of Science and Technology, and Huazhong University of Science and Technology