Large cation ethylammonium incorporated perovskite for efficient and spectra stable blue light-emitting diodes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32820166.
- Also identified by DOI 10.1038/s41467-020-17943-6 and PMC identifier 7441179.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Perovskite light-emitting diodes (PeLEDs) have showed significant progress in recent years; the external quantum efficiency (EQE) of electroluminescence in green and red regions has exceeded 20%, but the efficiency in blue lags far behind. Here, a large cation CH<sub>3</sub>CH<sub>2</sub>NH<sub>2</sub><sup>+</sup> is added in PEA<sub>2</sub>(CsPbBr<sub>3</sub>)<sub>2</sub>PbBr<sub>4</sub> perovskite to decrease the Pb-Br orbit coupling and increase the bandgap for blue emission. X-ray diffraction and nuclear magnetic resonance results confirmed that the EA has successfully replaced Cs<sup>+</sup> cations to form PEA<sub>2</sub>(Cs<sub>1-x</sub>EA<sub>x</sub>PbBr<sub>3</sub>)<sub>2</sub>PbBr<sub>4</sub>. This method modulates the photoluminescence from the green region (508 nm) into blue (466 nm), and over 70% photoluminescence quantum yield in blue is obtained. In addition, the emission spectra is stable under light and thermal stress. With configuration of PeLEDs with 60% EABr, as high as 12.1% EQE of sky-blue electroluminescence located at 488 nm has been demonstrated, which will pave the way for the full color display for the PeLEDs.