Organic OLEDs (organic light-emitting diodes) are light-emitting diodes made from carbon-containing compounds. Blue OLEDs are a particular challenge to make since their efficiency often has to be sacrificed in favour of stability. Dr Teets and his team have developed a new class of compounds that emit deep blue luminescence and are both stable and efficient.
"The design of compounds which effectively generate blue light is one of the largest remaining challenges in the continued development of OLEDs and other devices that are used in colour displays", explains Dr Thomas Teets, from the University of Houston.
"We have made an important design modification to a popular and successful category of blue-emitting iridium compounds. Our group has previously made this modification to compounds which generate sky blue or blue–green light, and in this work we targeted compounds that generate pure blue light.
"Most compounds of this type which emit pure blue light have an iridium metal atom surrounded by three identical building blocks. In this work we have introduced a way to substitute one of those three building blocks for a different type of building block that offers some advantages in terms of the efficiency and stability of blue-light emission."
The compounds in question are cyclometalated iridium complexes, and they could potentially be incorporated into improved blue OLEDs in the future, with better power efficiency and longer lifetimes.
"This would lead to the design of OLED phones with longer battery life and OLED TVs with lower power consumption", says Dr Teets. "In addition, these blue OLEDs could be longer lasting than currently available technologies, improving the longevity of phones and TVs that include these improved OLEDs."
This article is free to read in our open access, flagship journal Chemical Science: Thomas Teets et al., Chem. Sci., 2019, Advance Article. DOI: 10.1039/C9SC01386E. You can access our 2019 ChemSci Picks in this article collection.