A team of researchers from Northumbria, Cambridge, Imperial and Loughborough Universities has developed a new approach to producing blue light in organic light-emitting diode (OLED) displays. The researchers suggest that this development could potentially lead to more energy-efficient and longer-lasting screens for smartphones, televisions and other devices.

Key to this breakthrough is the design of a new light-emitting molecule that addresses the “blue OLED problem,” the researchers explained. Blue light-emitting subpixels in OLED displays are the least stable and most energy-intensive, often leading to screen burn-in and reduced device lifespans.

The figure presents three different matrix-free material combinations for OLED systems, labeled as System A, System B, and System C. a) The table shows the specific material combinations used in each of the three systems. b) The graph displays the electroluminescence (EL) spectra of System A, with photographs of the OLED emission from this system shown in the insets. c) The graph presents the EL spectra of System B. The inset shows the single-crystal X-ray diffraction (XRD) structure of the material En-Per, which is used in System B. d) The graph illustrates the EL spectra of System C, with photographs of the OLED emission from this system shown in the insets. Source: Nature MaterialsThe figure presents three different matrix-free material combinations for OLED systems, labeled as System A, System B, and System C. a) The table shows the specific material combinations used in each of the three systems. b) The graph displays the electroluminescence (EL) spectra of System A, with photographs of the OLED emission from this system shown in the insets. c) The graph presents the EL spectra of System B. The inset shows the single-crystal X-ray diffraction (XRD) structure of the material En-Per, which is used in System B. d) The graph illustrates the EL spectra of System C, with photographs of the OLED emission from this system shown in the insets. Source: Nature Materials

As such, the researchers’ molecule features shields that block destructive energy pathways and control how the molecules interact. By simplifying the emissive layer of the blue pixel to only two components, the team has reportedly maintained high efficiency while potentially driving down manufacturing costs.

The researchers explained: “The molecule we describe in this paper is one of the narrowest emitting blue molecules out there, which is very useful for screens because it allows for high color purity.”.

The findings are detailed in the article, “Suppression of Dexter transfer by covalent encapsulation for efficient matrix-free narrowband deep blue hyperfluorescent OLEDs,” which appears in the journal Nature Materials.

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