Revolution in light: Manganese replaces expensive rare earths in LEDs!

Revolution in light: Manganese replaces expensive rare earths in LEDs!

Almost all current light-emitting diodes (LEDs) require phosphors based on rare earths such as europium or cerium. These materials are not only expensive, but also difficult to obtain, as the raw material reserves are mainly located in China. An interdisciplinary research team from Heinrich Heine University Düsseldorf and the University of Innsbruck has now developed a promising alternative: manganese. Loud the Heinrich Heine University Düsseldorf manganese enables the production of a new, efficient phosphor that can produce white light.

In the journal *Applied Chemistry* it was proven that the doubly positively charged manganese ion (Mn2+) is able to emit cyan light and thus produce white light in combination with blue semiconductor LEDs. This development could significantly reduce LED technology's dependence on rare earths, as manganese is widespread and easily mined in the Earth's crust, as well Machinery market highlights.

The benefits of manganese

Manganese ions are not only more common than previously used elements, but also offer advantages in the flexibility of coordination geometries. While the luminescence of Mn2+ remains thermally stable and can withstand high temperatures of up to 150 °C, its use in LEDs also presents challenges. A major disadvantage of Mn2+ is its inefficient absorption, which requires high power densities to achieve sufficient brightness. The researchers led by Jun.-Prof. Dr. Markus Suta and Prof. Dr. Hubert Huppertz are working on determining the power densities required to be competitive with existing technologies.

A noticeable challenge in implementation also lies in the luminescent color. Manganese ions can emit different colors (green or red) depending on the number of surrounding oxygen atoms, such as the University of Innsbruck described in their reporting. This allows modulated light emission, which could be advantageous for various applications.

Summary and outlook

But the use of manganese as a phosphor is not the only focus of research. The substance Zn[B2(SO4)4] was discovered for the first time in 2019, which can be processed as a “solid solution” in combination with manganese chloride. These new approaches show that manganese not only serves as a cost-effective, alternative starting resource for LEDs, but also drives the development of innovative materials. However, to create highly efficient LEDs, further research is necessary to determine the exact properties of manganese-activated phosphors.

Overall, research into manganese could revolutionize LED technology and reduce dependence on expensive and environmentally harmful raw materials. The researchers are therefore faced with the challenge of further optimizing the results and bringing the subsystems into a marketable form.