Spectroscopy of Single CdSe Magic-Sized Nanocrystals

Fuente: arXiv
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Main Authors: Nagamine, Gabriel, Santen, Julian, Crimmann, Juri G., Mule, Aniket S., Pun, Andrew B., Norris, David J.
Format: Preprint
Published: 2024
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author Nagamine, Gabriel
Santen, Julian
Crimmann, Juri G.
Mule, Aniket S.
Pun, Andrew B.
Norris, David J.
author_facet Nagamine, Gabriel
Santen, Julian
Crimmann, Juri G.
Mule, Aniket S.
Pun, Andrew B.
Norris, David J.
contents Chemical syntheses that provide nanocrystals (NCs) with narrow distributions in size and shape are critical for NC research. This has led to the investigation of magic-sized NCs (MSNCs), a class of semiconductor crystallites that grow in discrete steps, potentially offering a single size and shape (i.e., monodispersity). However, the photoluminescence (PL) spectra of CdSe MSNCs measured at room temperature have been reported to be broader than those of state-of-the-art quantum dots. This difference could be due to the smaller size of MSNCs, which broadens their line widths, or due to their residual size dispersity. To better understand the optical performance of MSNCs, here we perform single-particle spectroscopy. Our results show that, while CdSe MSNCs do exhibit particle-to-particle variations that lead to modest broadening of their ensemble emission spectra, the largest contribution comes from the single-particle line width. By examining MSNCs with different sizes and shells, we conclude that this single-particle broadening is consistent with exciton coupling to acoustic phonons from the NC surface. Because of their small size, this coupling and the role of residual size dispersity have a larger impact on the ensemble emission line widths. Notably, when small (<2.7 nm diameter) MSNCs and quantum dots are compared, the ensemble PL line widths of MSNCs are actually sharper. Due to their small size, MSNCs also exhibit strong anti-bunching $[g^{(2)}(0) \sim 0.05]$ at room temperature. Thus, MSNCs represent a bright, spectrally pure class of quantum emitter, useful for applications in optoelectronic and quantum-information technologies where strong three-dimensional confinement is required.
format Preprint
id arxiv_https___arxiv_org_abs_2407_09114
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Spectroscopy of Single CdSe Magic-Sized Nanocrystals
Nagamine, Gabriel
Santen, Julian
Crimmann, Juri G.
Mule, Aniket S.
Pun, Andrew B.
Norris, David J.
Mesoscale and Nanoscale Physics
Materials Science
Optics
Quantum Physics
Chemical syntheses that provide nanocrystals (NCs) with narrow distributions in size and shape are critical for NC research. This has led to the investigation of magic-sized NCs (MSNCs), a class of semiconductor crystallites that grow in discrete steps, potentially offering a single size and shape (i.e., monodispersity). However, the photoluminescence (PL) spectra of CdSe MSNCs measured at room temperature have been reported to be broader than those of state-of-the-art quantum dots. This difference could be due to the smaller size of MSNCs, which broadens their line widths, or due to their residual size dispersity. To better understand the optical performance of MSNCs, here we perform single-particle spectroscopy. Our results show that, while CdSe MSNCs do exhibit particle-to-particle variations that lead to modest broadening of their ensemble emission spectra, the largest contribution comes from the single-particle line width. By examining MSNCs with different sizes and shells, we conclude that this single-particle broadening is consistent with exciton coupling to acoustic phonons from the NC surface. Because of their small size, this coupling and the role of residual size dispersity have a larger impact on the ensemble emission line widths. Notably, when small (<2.7 nm diameter) MSNCs and quantum dots are compared, the ensemble PL line widths of MSNCs are actually sharper. Due to their small size, MSNCs also exhibit strong anti-bunching $[g^{(2)}(0) \sim 0.05]$ at room temperature. Thus, MSNCs represent a bright, spectrally pure class of quantum emitter, useful for applications in optoelectronic and quantum-information technologies where strong three-dimensional confinement is required.
title Spectroscopy of Single CdSe Magic-Sized Nanocrystals
topic Mesoscale and Nanoscale Physics
Materials Science
Optics
Quantum Physics
url https://arxiv.org/abs/2407.09114