Efficient White Electroluminescence from Cu-based Perovskite Achieved by High Hole Injection Core/Shell Structures.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40166819.
- Also identified by DOI 10.1002/adma.202417678 and PMC identifier 12087732.
- Licence recorded as CC BY-NC.
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Abstract
The copper-based (Cu-based) halide perovskite possesses eco-friendly features, bright self-trapped-exciton (broadband) emission, and a high color-rendering index (CRI) for achieving white emission. However, the limited hole injection (HI) of Cu-based perovskites has been bottle-necking the efficiency of white electroluminescence and thus their application in white perovskite light-emitting diodes (W-PeLEDs). In this study, we demonstrate a p-type cuprous sulfide (Cu<sub>2</sub>S) lattice-connectedly capping over Cs<sub>3</sub>Cu<sub>2</sub>I<sub>5</sub> to form lattice-matched core/shell nanocrystals (NCs) by controlling the reactivity of sulfur (S) precursor in the synthesis. Interestingly, the resultant Cs<sub>3</sub>Cu<sub>2</sub>I<sub>5</sub>/Cu<sub>2</sub>S NCs significantly enhance the hole mobility compared to Cs<sub>3</sub>Cu<sub>2</sub>I<sub>5</sub> NCs. Besides, the photoluminescence quantum yield of Cs<sub>3</sub>Cu<sub>2</sub>I<sub>5</sub> NCs increases from 26.8% to 70.6% after the Cu<sub>2</sub>S lattice-connected capping. Consequently, by establishing the structure of CsCu<sub>2</sub>I<sub>3</sub>/Cs<sub>3</sub>Cu<sub>2</sub>I<sub>5</sub>/Cu<sub>2</sub>S in W-PeLEDs, an external quantum efficiency of 3.45% and a CRI of 91 is realized, representing the highest reported electroluminescent performance in lead-free Cu-based W-PeLEDs. These findings contribute to establishing guidelines and effective strategies for designing broadband electroluminescent materials and device structures of PeLEDs.