Jump to main content
Jump to site search


Boosting the efficiency of inverted quantum dot light-emitting diodes by balancing charge densities and suppressing exciton quenching through band alignment

Author affiliations

Abstract

We report an inverted and multilayer quantum dot light emitting diode (QLED) which boosts high efficiency by tuning the energy band alignment between charge transport and light emitting layers. The electron transport layer (ETL) was ZnO nanoparticles (NPs) with an optimized doping concentration of cesium azide (CsN3) to effectively reduce electron flow and balance charge injection. This is by virtue of a 0.27 eV upshift of the ETL's conduction band edge, which inhibits the quenching of excitons and preserves the superior emissive properties of the quantum dots due to the insulating characteristics of CsN3. The demonstrated QLED exhibits a peak current efficiency, power efficiency and external quantum efficiency of up to 13.5 cd A−1, 10.6 lm W−1 and 13.4% for the red QLED, and correspondingly 43.1 cd A−1, 33.6 lm W−1 and 9.1% for green, and 4.1 cd A−1, 2.0 lm W−1 and 6.6% for the blue counterparts. Compared with QLEDs without optimization, the performance of these modified devices shows drastic improvement by 95.6%, 39.4% and 36.7%, respectively. This novel device architecture with heterogeneous energy levels reported here offers a new design strategy for next-generation high efficiency QLED displays and solid-state lighting technologies.

Graphical abstract: Boosting the efficiency of inverted quantum dot light-emitting diodes by balancing charge densities and suppressing exciton quenching through band alignment

Back to tab navigation

Supplementary files

Publication details

The article was received on 22 Aug 2017, accepted on 27 Nov 2017 and first published on 28 Nov 2017


Article type: Paper
DOI: 10.1039/C7NR06248F
Citation: Nanoscale, 2018, Advance Article
  •   Request permissions

    Boosting the efficiency of inverted quantum dot light-emitting diodes by balancing charge densities and suppressing exciton quenching through band alignment

    J. Pan, C. Wei, L. Wang, J. Zhuang, Q. Huang, W. Su, Z. Cui, A. Nathan, W. Lei and J. Chen, Nanoscale, 2018, Advance Article , DOI: 10.1039/C7NR06248F

Search articles by author

Spotlight

Advertisements