Ultra-bright and highly efficient inorganic based perovskite light-emitting diodes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28589960.
- Also identified by DOI 10.1038/ncomms15640 and PMC identifier 5467226.
- 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
Inorganic perovskites such as CsPbX<sub>3</sub> (X=Cl, Br, I) have attracted attention due to their excellent thermal stability and high photoluminescence quantum efficiency. However, the electroluminescence quantum efficiency of their light-emitting diodes was <1%. We posited that this low efficiency was a result of high leakage current caused by poor perovskite morphology, high non-radiative recombination at interfaces and perovskite grain boundaries, and also charge injection imbalance. Here, we incorporated a small amount of methylammonium organic cation into the CsPbBr<sub>3</sub> lattice and by depositing a hydrophilic and insulating polyvinyl pyrrolidine polymer atop the ZnO electron-injection layer to overcome these issues. As a result, we obtained light-emitting diodes exhibiting a high brightness of 91,000 cd m<sup>-2</sup> and a high external quantum efficiency of 10.4% using a mixed-cation perovskite Cs<sub>0.87</sub>MA<sub>0.13</sub>PbBr<sub>3</sub> as the emitting layer. To the best of our knowledge, this is the brightest and most-efficient green perovskite light-emitting diodes reported to date.