Abstract
Perovskite nanocrystals exhibit high photoluminescence quantum yields (PLQYs) and tunable bandgaps from ultraviolet to infrared. However, blue perovskite light-emitting diodes (LEDs) suffer from color instability under applied bias. Developing narrow-bandwidth deep-blue emitters will maximize the color gamut of display technologies. Mixed anion approaches suffer from halide segregation that leads to their spectral instability. Here instead, a mixed cation strategy is employed whereby Rb+ is directly incorporated during synthesis into CsPbBr3 nanocrystals. Blue-emitting perovskite quantum dots (QDs) with stable photoluminescence, PLQYs greater than 60%, tunable emission from 460 to 500 nm, and narrow emission linewidths (<25 nm) are reported. The strategy retains a pure bromine crystal structure resulting in color-pure stable electroluminescence at operating voltages of up to 10 V, peak external quantum efficiencies (EQEs) of 0.87% and 0.11% for sky-blue (490 nm), and deep-blue (464 nm) devices. The sky-blue devices exhibit the highest combined luminance of 93 cd m−2 at an EQE of 0.75%, the best reported to date of perovskite QD LEDs.
| Original language | English (US) |
|---|---|
| Article number | 1901440 |
| Journal | Advanced Optical Materials |
| Volume | 7 |
| Issue number | 24 |
| DOIs | |
| State | Published - Dec 1 2019 |
Funding
P.T. and D.M. contributed equally to this work. P.T. wrote the manuscript and led all experimental work. D.M. helped to fabricate light\u2010emitting diodes. B.C. helped with electron microscopy characterization of materials. P.T would like to thank Sjoerd Hoogland for his valuable insights and discussions. E.H.S supervised this work and provided edits to the manuscript. The authors would like to acknowledge Dr. Jimi Tjong, Paul Dellock, and Harry Lobo from Ford Motor Company for their valuable discussions. This work was financially supported by Natural Sciences and Engineering Research Council of Canada (NSERC). This work was also partially funded by Ford PDC, Ford PERDC, and Ford's University Research Program (URP). P.T acknowledges funding from NSERC. M.I.S. acknowledges the support of Banting Postdoctoral Fellowship Program. P.T. and D.M. contributed equally to this work. P.T. wrote the manuscript and led all experimental work. D.M. helped to fabricate light-emitting diodes. B.C. helped with electron microscopy characterization of materials. P.T would like to thank Sjoerd Hoogland for his valuable insights and discussions. E.H.S supervised this work and provided edits to the manuscript. The authors would like to acknowledge Dr. Jimi Tjong, Paul Dellock, and Harry Lobo from Ford Motor Company for their valuable discussions. This work was financially supported by Natural Sciences and Engineering Research Council of Canada (NSERC). This work was also partially funded by Ford PDC, Ford PERDC, and Ford's University Research Program (URP). P.T acknowledges funding from NSERC. M.I.S. acknowledges the support of Banting Postdoctoral Fellowship Program.
Keywords
- LEDs
- blue emission
- halide perovskites
- light-emitting diodes
- perovskite quantum dots
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics