Major Advancement in Blue Perovskite LED Performance
by Simon Mansfield
Sydney, Australia (SPX) Mar 19, 2024
In a collaborative breakthrough, Prof. CUI Linsong’s team at the University of Science and Technology of China (USTC) and Prof. Samuel D. Stranks’ team from the University of Cambridge have unveiled a pioneering method to significantly advance the performance of blue perovskite light-emitting diodes (LEDs), as reported in Nature Photonics on January 26, 2024.
Despite the rapid development of green, red, and near-infrared perovskite LEDs, blue variants have remained a persistent challenge, hindering full spectrum advancement in this promising next-gen lighting and display technology. The researchers introduced a novel multifunctional ionic additive, Bis(triphenylphosphine)iminium chloride (PPNCl), that tactically manipulates perovskite material properties to overcome this hurdle.
PPNCl’s ability to establish multiple charged resonance forms and a dynamic electronic state plays a crucial role in enhancing blue perovskite LEDs. By fostering precise control over perovskite composition and phase distribution, the additive minimizes non-radiative recombination and ion migration, directly translating to boosted efficiency and stability.
The additive’s interaction with perovskite components through hydrogen bonding modifies the crystallization pathway towards higher-dimensional phases, known for superior luminescence. Further insights from transient absorption (TA) spectroscopy show that PPNCl expedites energy transfer to these high-dimensional phases, reducing energy losses previously marred by non-radiative processes.
PPNCl’s dual role extends to defect passivation and inhibition of halide ion migration within perovskite films, resulting in markedly improved luminescence efficiency and spectral consistency. The culmination of these advancements is the realization of blue perovskite LEDs with a peak external quantum efficiency (EQE) of 21.4% at an emission peak of 483 nm – the highest recorded efficiency for blue perovskite LEDs thus far. Notably, the longevity of these LEDs has seen a near 30-fold increase.
This research signifies a major leap forward in the development of blue perovskite LEDs, potentially revolutionizing lighting and display technologies with its efficiency and stability enhancements.
Research Report:Efficient blue electroluminescence from reduced-dimensional perovskites
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