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Fine structure of nearly isotropic bright excitons in InP/ZnSe colloidal quantum dots

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Abstract
The fine structure of exciton states in colloidal quantum dots (QDs) results from the compound effect of anisotropy and electron-hole exchange. By means of single-dot photoluminescence spectroscopy, we show that the emission of photoexcited InP/ZnSe QDs originates from radiative re-combination of such fine structure exciton states. Depending on the excitation power, we identify a bright exciton doublet, a trion singlet, and a biexciton doublet line that all show pronounced polarization. Fluorescence line narrowing spectra of an ensemble of InP/ZnSe QDs in magnetic fields demonstrate that the bright exciton effectively consists of three states. The Zeeman splitting of these states is well described by an isotropic exciton model, where the fine structure is dominated by electron-hole exchange and shape anisotropy leads to only a minor splitting of the F = 1 triplet. We argue that excitons in InP-based QDs are nearly isotropic because the particular ratio of light and heavy hole masses in InP makes the exciton fine structure insensitive to shape anisotropy.
Keywords
BAND-EDGE EXCITON, DYNAMICS, DARK, SPECTROSCOPY, NANOCRYSTALS

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MLA
Brodu, Annalisa, et al. “Fine Structure of Nearly Isotropic Bright Excitons in InP/ZnSe Colloidal Quantum Dots.” JOURNAL OF PHYSICAL CHEMISTRY LETTERS, vol. 10, no. 18, 2019, pp. 5468–75, doi:10.1021/acs.jpclett.9b01824.
APA
Brodu, A., Chandrasekaran, V., Scarpelli, L., Buhot, J., Masia, F., Ballottin, M. V., … Hens, Z. (2019). Fine structure of nearly isotropic bright excitons in InP/ZnSe colloidal quantum dots. JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 10(18), 5468–5475. https://doi.org/10.1021/acs.jpclett.9b01824
Chicago author-date
Brodu, Annalisa, Vigneshwaran Chandrasekaran, Lorenzo Scarpelli, Jonathan Buhot, Francesco Masia, Mariana V Ballottin, Marion Severijnen, et al. 2019. “Fine Structure of Nearly Isotropic Bright Excitons in InP/ZnSe Colloidal Quantum Dots.” JOURNAL OF PHYSICAL CHEMISTRY LETTERS 10 (18): 5468–75. https://doi.org/10.1021/acs.jpclett.9b01824.
Chicago author-date (all authors)
Brodu, Annalisa, Vigneshwaran Chandrasekaran, Lorenzo Scarpelli, Jonathan Buhot, Francesco Masia, Mariana V Ballottin, Marion Severijnen, Mickaël Tessier, Dorian Dupont, Freddy T Rabouw, Peter CM Christianen, Celso de Mello Donega, Daniel Vanmaekelbergh, Wolfgang Langbein, and Zeger Hens. 2019. “Fine Structure of Nearly Isotropic Bright Excitons in InP/ZnSe Colloidal Quantum Dots.” JOURNAL OF PHYSICAL CHEMISTRY LETTERS 10 (18): 5468–5475. doi:10.1021/acs.jpclett.9b01824.
Vancouver
1.
Brodu A, Chandrasekaran V, Scarpelli L, Buhot J, Masia F, Ballottin MV, et al. Fine structure of nearly isotropic bright excitons in InP/ZnSe colloidal quantum dots. JOURNAL OF PHYSICAL CHEMISTRY LETTERS. 2019;10(18):5468–75.
IEEE
[1]
A. Brodu et al., “Fine structure of nearly isotropic bright excitons in InP/ZnSe colloidal quantum dots,” JOURNAL OF PHYSICAL CHEMISTRY LETTERS, vol. 10, no. 18, pp. 5468–5475, 2019.
@article{8625311,
  abstract     = {The fine structure of exciton states in colloidal quantum dots (QDs) results from the compound effect of anisotropy and electron-hole exchange. By means of single-dot photoluminescence spectroscopy, we show that the emission of photoexcited InP/ZnSe QDs originates from radiative re-combination of such fine structure exciton states. Depending on the excitation power, we identify a bright exciton doublet, a trion singlet, and a biexciton doublet line that all show pronounced polarization. Fluorescence line narrowing spectra of an ensemble of InP/ZnSe QDs in magnetic fields demonstrate that the bright exciton effectively consists of three states. The Zeeman splitting of these states is well described by an isotropic exciton model, where the fine structure is dominated by electron-hole exchange and shape anisotropy leads to only a minor splitting of the F = 1 triplet. We argue that excitons in InP-based QDs are nearly isotropic because the particular ratio of light and heavy hole masses in InP makes the exciton fine structure insensitive to shape anisotropy.},
  author       = {Brodu, Annalisa and Chandrasekaran, Vigneshwaran and Scarpelli, Lorenzo and Buhot, Jonathan and Masia, Francesco and Ballottin, Mariana V and Severijnen, Marion and Tessier, Mickaël and Dupont, Dorian and Rabouw, Freddy T and Christianen, Peter CM and de Mello Donega, Celso and Vanmaekelbergh, Daniel and Langbein, Wolfgang and Hens, Zeger},
  issn         = {1948-7185},
  journal      = {JOURNAL OF PHYSICAL CHEMISTRY LETTERS},
  keywords     = {BAND-EDGE EXCITON,DYNAMICS,DARK,SPECTROSCOPY,NANOCRYSTALS},
  language     = {eng},
  number       = {18},
  pages        = {5468--5475},
  title        = {Fine structure of nearly isotropic bright excitons in InP/ZnSe colloidal quantum dots},
  url          = {http://dx.doi.org/10.1021/acs.jpclett.9b01824},
  volume       = {10},
  year         = {2019},
}

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