Researchers at UNSW Sydney’s ARC Center of Excellence in Exciton Science have demonstrated that OLEDs – a semiconductor material commonly found in flat-screen TVs, smartphone screens and other digital displays – can be used to map magnetic fields using magnetic resonance. This technological advance in sensing magnetic fields has important applications in scientific research, industry and medicine.
Published in the prestigious journal Nature Communications, the technique works on a microchip scale and – unlike other common approaches – does not require the input of a laser.
Dr Rugang Geng works at UNSW Sydney. Source: Exciton Science
Most existing quantum sensing and magnetic field imaging devices are relatively large and expensive, requiring optical pumping (from high-power lasers) or very low cryogenic temperatures. This limits the device integration potential and commercial scalability of this approach.
In contrast, the OLED sensing device prototype in this work will eventually be small, flexible and mass-producible.
The technologies involved in achieving this goal are electrically detected magnetic resonance (EDMR) and optically detected magnetic resonance (ODMR). This is achieved using cameras and microwave electronics to optically detect magnetic resonance, the same physics that enable magnetic resonance imaging (MRI). Using OLEDs for EDMR and ODMR depends on correctly exploiting the spin behavior of electrons when they are in proximity to a magnetic field.
OLEDs, which are highly sensitive to magnetic fields, are already appearing in mass-produced electronics such as televisions and smartphones, making them an attractive prospect for commercial development among new technologies.
Professor Dane McCamey of UNSW, who is also Exciton Science’s lead researcher, said: “Our device has been designed to be compatible with commercially available OLED technology, offering the unique ability to map magnetic fields over large areas and even curved surfaces.
“You could imagine using this technology being added to a smartphone to aid in telemedicine diagnosis, or to identify defects in materials.”
Lead author Dr Rugang Geng, from UNSW and Exciton Science, added: “While our study demonstrates a clear technical pathway, more work is needed to improve sensitivity and read times.”
Professor McCamey said a patent had been applied for (Australian patent application 2022901738) with a view to potential commercialization of the technology.
