Quantum Shells Boost the Optical Gain of Lasing Media

James Cassidy, Benjamin T. Diroll, Navendu Mondal, David B. Berkinsky, Kehui Zhao, Dulanjan Harankahage, Dmitry Porotnikov, Reagan Gately, Dmitriy Khon, Andrew Proppe, Moungi G. Bawendi, Richard D. Schaller, Anton V. Malko, Mikhail Zamkov*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


Auger decay of multiple excitons represents a significant obstacle to photonic applications of semiconductor quantum dots (QDs). This nonradiative process is particularly detrimental to the performance of QD-based electroluminescent and lasing devices. Here, we demonstrate that semiconductor quantum shells with an “inverted” QD geometry inhibit Auger recombination, allowing substantial improvements to their multiexciton characteristics. By promoting a spatial separation between multiple excitons, the quantum shell geometry leads to ultralong biexciton lifetimes (>10 ns) and a large biexciton quantum yield. Furthermore, the architecture of quantum shells induces an exciton-exciton repulsion, which splits exciton and biexciton optical transitions, giving rise to an Auger-inactive single-exciton gain mode. In this regime, quantum shells exhibit the longest optical gain lifetime reported for colloidal QDs to date (>6 ns), which makes this geometry an attractive candidate for the development of optically and electrically pumped gain media.

Original languageEnglish (US)
Pages (from-to)3017-3026
Number of pages10
JournalACS nano
Issue number2
StatePublished - Feb 22 2022


  • X-ray
  • biexciton
  • laser diode
  • light
  • nanocrystal
  • scintillator
  • trion

ASJC Scopus subject areas

  • General Engineering
  • General Physics and Astronomy
  • General Materials Science


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