Quantum Shells Boost the Optical Gain of Lasing Media

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

doi:10.1021/acsnano.1c10404

DOE OSTI · 1865404

Quantum Shells Boost the Optical Gain of Lasing Media

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

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Abstract

Auger decay of multiple excitons represents one of the main obstacles to photonic applications of semiconductor quantum dots (QDs). These non-radiative processes are particularly detrimental to the performance of QD-based electroluminescent and lasing devices. Here, we demonstrate that by using semiconductor quantum shells with an “inverted” QD geometry, it is possible to inhibit Auger recombination, allowing extraordinary improvements to their multi-exciton characteristics. Additionally, we show that quantum shells result in ultralong biexciton lifetimes (>10 ns), and an associated biexciton quantum yield of up to 81%. Furthermore, the energy-dispersive architecture of quantum shells leads to exciton-exciton repulsion, which splits the single-exciton and bi-exciton optical transitions. In this regime, quantum shells produce the longest optical gain lifetime reported for colloidal QDs to date (> 6 ns) over a broad amplification bandwidth. Therefore, the employment of quantum shells in optically- or electrically-pumped gain media can lead to a substantial improvement in device performance.

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Cassidy, James, Diroll, Benjamin T., Mondal, Navendu, Berkinsky, David B., Zhao, Kehui, Harankahage, Dulanjan, Porotnikov, Dmitry, Gately, Reagan, Khon, Dmitriy, Proppe, Andrew, Bawendi, Moungi G., Schaller, Richard D., Malko, Anton V., Zamkov, Mikhail. 2022-02-07. Quantum Shells Boost the Optical Gain of Lasing Media. https://doi.org/10.1021/acsnano.1c10404

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