Brightening deep-blue perovskite light-emitting diodes: A path to Rec. 2020.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38758786.
- Also identified by DOI 10.1126/sciadv.adn8465 and PMC identifier 11100563.
- Licence recorded as CC BY-NC.
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Abstract
Deep-blue perovskite light-emitting diodes (PeLEDs) of high purity are highly sought after for next-generation displays complying with the Rec. 2020 standard. However, mixed-halide perovskite materials designed for deep-blue emitters are prone to halide vacancies, which readily occur because of the low formation energy of chloride vacancies. This degrades bandgap instability and performance. Here, we propose a chloride vacancy-targeting passivation strategy using sulfonate ligands with different chain lengths. The sulfonate groups have a strong affinity for lead(II) ions, effectively neutralizing vacancies. Our strategy successfully suppressed phase segregation, yielding color-stable deep-blue PeLEDs with an emission peak at 461 nanometers and a maximum luminance (<i>L</i><sub><i>max</i></sub>) of 2707 candela per square meter with external quantum efficiency (EQE) of 3.05%, one of the highest for Rec. 2020 standard-compliant deep-blue PeLEDs. We also observed a notable increase in EQE up to 5.68% at <i>L</i><sub><i>max</i></sub> of 1978 candela per square meter with an emission peak at 461 nanometers by changing the carbon chain length.