Self-assembled monolayer-based blue perovskite LEDs.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37683007.
- Also identified by DOI 10.1126/sciadv.adh2140 and PMC identifier 10491221.
- Licence recorded as CC BY-NC.
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Abstract
Blue perovskite light-emitting diodes (LEDs) have shown external quantum efficiencies (EQEs) of more than 10%; however, devices that emit in the true blue-those that accord with the emission wavelength required for Rec. 2100 primary blue-have so far been limited to EQEs of ~6%. We focused here on true blue emitting CsPbBr<sub>3</sub> colloidal nanocrystals (c-NCs), finding in early studies that they suffer from a high charge injection barrier, a problem exacerbated in films containing multiple layers of nanocrystals. We introduce a self-assembled monolayer (SAM) active layer that improves charge injection. We identified a bifunctional capping ligand that simultaneously enables the self-assembly of CsPbBr<sub>3</sub> c-NCs while passivating surface traps. We report, as a result, SAM-based LEDs exhibit a champion EQE of ~12% [CIE of (0.132, 0.069) at 4.0 V with a luminance of 11 cd/m<sup>2</sup>], and 10-fold-enhanced operating stability relative to the best previously reported Rec. 2100-blue perovskite LEDs.