Nanostructured solar cells are costly to produce because they require rare and expensive metals such as ruthenium. However, a team of researchers from the Queen Mary, University of London has found a cheaper and abundant alternative from shrimp shells.
Chitin and chitosan are derivative materials naturally found in the shells of shrimps and other crustaceans. Researchers used a process called hydrothermal carbonisation to create the carbon quantum dots using these two materials before coating them with the standard zinc oxide to make solar cells.
Quantum dots are a popular modern structure for producing photovoltaic cells because they are capable of releasing more energy than normal photovoltaic cells.
However, the shrimp-derived solar cell prototypes are still on their earliest stage according to the researchers. The efficiency of these prototypes to produce electricity remains very low. Further reengineering and other technological improvements could perhaps one day catapult these types of solar cells to commercial viability. Once improved, these shrimp-derived solar cells could be placed in everything from wearable chargers for tablets, phones, and smartwatches, to portable lighting fixtures and semi-transparent films over windows.
“This could be a great new way to make these versatile, quick and easy to produce solar cells from readily available, sustainable materials,” said Dr. Joe Briscoe, one of the researchers. “Once we’ve improved their efficiency, they could be used anywhere that solar cells are used now, particularly to charge the kinds of devices people carry with them everyday.”
Chitin and chitosan have become commercially available over the past few years due to their agricultural, industrial, medicinal, and pharmaceutical applications. Chitin, for example, has been used as a fertiliser while chitosan has been used as an eco-friendly pesticide. Furthermore, medical researchers found out that chitin and chitosan can accelerate wound healing, thus making them critical additives in military-grade first aid kits.
“New techniques mean that we can produce exciting new materials from organic byproducts that are easily available,” said Magdalena Titirici, professor of sustainable materials technology at QMUL. “Sustainable materials can be both high-tech and low-cost.”
Further details of the research are in the article “Biomass-Derived Carbon Quantum Dot Sensitizers for Solid-State Nanostructured Solar Cells” published in 2015 in the journal Angewandte Chemie International Edition.