Polarized near-infrared intersubband absorptions in CdSe colloidal quantum wells

Benjamin T. Diroll*, Menglu Chen, Igor Coropceanu, Kali R. Williams, Dmitri V. Talapin, Philippe Guyot-Sionnest, Richard D. Schaller

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Colloidal quantum wells are two-dimensional materials grown with atomically-precise thickness that dictates their electronic structure. Although intersubband absorption in epitaxial quantum wells is well-known, analogous observations in non-epitaxial two-dimensional materials are sparse. Here we show that CdSe nanoplatelet quantum wells have narrow (30–200 meV), polarized intersubband absorption features when photoexcited or under applied bias, which can be tuned by thickness across the near-infrared (NIR) spectral window (900–1600 nm) inclusive of important telecommunications wavelengths. By examination of the optical absorption and polarization-resolved measurements, the NIR absorptions are assigned to electron intersubband transitions. Under photoexcitation, the intersubband features display hot carrier and Auger recombination effects similar to excitonic absorptions. Sequenced two-color photoexcitation permits the sub-picosecond modulation of the carrier temperature in such colloidal quantum wells. This work suggests that colloidal quantum wells may be promising building blocks for NIR technologies.

Original languageEnglish (US)
Article number4511
JournalNature communications
Volume10
Issue number1
DOIs
StatePublished - Dec 1 2019

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

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