An international research team, involving Newcastle University experts, developed visible light communication (VLC) setup capable of a data rate of 2.2 Mb/s by employing a new type of organic light-emitting diodes (OLEDs).

To reach this speed, the scientists created new far-red/near-infrared, solution-processed OLEDs. And by extending the spectral range to 700–1000 nm, they successfully expanded the bandwidth and achieved the fastest-ever data speed recorded in real-time for solution-based OLEDs.

Described in the journal Nature Light, the new OLEDs (pictured) create opportunities for new internet-of-things (IoT) connectivity, as well as wearable and implantable biosensors technology. 

The project is a collaboration between Newcastle University, University College London, the London Centre for Nanotechnology, the Institute of Organic Chemistry, Polish Academy of Sciences (Warsaw, Poland) and the Institute for the Study of Nanostructured Materials - Research National Council (CNR-ISMN, Bologna, Italy).

Opening up new opportunities

Dr Paul Haigh, Lecturer in Communications at Newcastle University’s Intelligent Sensing and Communications Group, was part of the research team. He led the development of a real-time transmission of signals that transmit as quickly as possible. He achieved this by using information modulation formats developed in-house, achieving approximately 2.2 Mb/s.

Dr Haigh said: “Our team developed highly efficient long wavelength (far red/near-infrared) polymer LEDs free of heavy metals which has been a long-standing research challenge in the organic optoelectronics community. Achieving such high data rates opens up opportunities for the integration of portable, wearable or implantable organic biosensors into visible/ nearly (in)visible light communication links.”

The demand for faster data transmission speeds is driving the popularity of light-emitting devices in VLC systems. LEDs have multiple applications and are used lighting systems, mobile phones and TV displays. While OLEDs don’t offer the same speed as inorganic LEDs and laser diodes do, they are cheaper to produce, recyclable and more sustainable.

The data rate the team achieved through the pioneering device is high enough to support an indoor point-to-point link, with a view of IoT applications. The researchers highlight the possibility of achieving such data rates without computationally complex and power-demanding equalisers. Together with the absence of toxic heavy metals in the active layer of the OLEDs, the new VLC setup is promising for the integration of portable, wearable or implantable organic biosensors.

In the future, we may see applications of this technology in many different areas, ranging from individual communication-enabled pixels in display technologies right through to under- or through-skin biosensing for active health monitoring and faster care linkage.

Reference

Minotto, A., Haigh, P.A., Łukasiewicz, Ł.G. et al. Visible light communication with efficient far-red/near-infrared polymer light-emitting diodes. Light Sci Appl 9, 70 (2020). https://doi.org/10.1038/s41377-020-0314-z