Replacing one-thousandth of the lead atom with manganese can triple the luminescence of halide perovskite quantum dots. An international research team has developed a new technology that can be used to make more efficient low-cost luminescent materials that are flexible and can be printed using inkjet technology.
Researchers led by the University of Cambridge in the UK and the Technical University of Munich in Germany found that by replacing one-thousandth of the lead atoms with manganese, they can triple the luminescence of halide perovskite quantum dots.
This doping causes charge carriers to get stuck in certain parts of the material's crystal structure, where they recombine and emit light. The findings are published in the Journal of the American Chemical Society and can be used for low-cost printable and flexible LED lighting, smart phone displays or cheap lasers
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Researchers from the University of Cambridge collaborated with the Daniel Congreve group of Harvard University in the United States. They are experts in manufacturing quantum dots.
A detailed investigation using laser spectroscopy revealed the origin of this observation. "We found that electric charges are clustered together in our doped crystal regions," said Sascha Feldmann of the Cavendish Laboratory in Cambridge, the first author of the study. "Once positioned, these high-energy charges can meet each other and recombine to emit light in a very effective way."
"We hope this fascinating discovery: Even the smallest changes to the chemical composition can greatly improve the performance of the material, which will pave the way for cheap and ultra-bright LED displays and lasers in the near future." Senior author Felix Deschler said that he worked jointly at the Cavendish and Walter Schottky Institute of the Technical University of Munich.
In the future, researchers hope to find more effective dopants, which will help make these advanced optical technologies popular all over the world.
