Influence of particle size and dielectric environment on radiative lifetimes of colloidal cadmium selenide single photon emitters

Abstract High repetition rate single-photon emitters are essential for all-optical quantum information processing, communications and metrology. The spontaneous emission lifetimes of colloidal cadmium selenide quantum dots are typically of the order of 10 ns, severely limiting their brightness and t...

Full description

Saved in:
Bibliographic Details
Main Authors: V. Manojkumar, Geetha K. Varier, Radhika Vathsan, P. Nandakumar
Format: Article
Language:English
Published: Nature Portfolio 2025-04-01
Series:Scientific Reports
Subjects:
Online Access:https://doi.org/10.1038/s41598-025-99148-9
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850172968729051136
author V. Manojkumar
Geetha K. Varier
Radhika Vathsan
P. Nandakumar
author_facet V. Manojkumar
Geetha K. Varier
Radhika Vathsan
P. Nandakumar
author_sort V. Manojkumar
collection DOAJ
description Abstract High repetition rate single-photon emitters are essential for all-optical quantum information processing, communications and metrology. The spontaneous emission lifetimes of colloidal cadmium selenide quantum dots are typically of the order of 10 ns, severely limiting their brightness and therefore their potential applications in quantum devices. Here we report on single-photon emission at room temperature with nanosecond lifetime from cadmium selenide quantum dots embedded in a polymer matrix. The study shows that the emission lifetime can be tuned by appropriately choosing the particle size and the dielectric constant of the surrounding medium. The quantum dots are synthesized using a green synthesis protocol and surface passivated using oleic acid. A Hanbury Brown and Twiss setup attached to an in-house constructed confocal microscope is used to efficiently couple and characterize the single-photon emission from an array of quantum dots. Detailed analysis of the second-order correlation function ( $$g^{(2)}(\tau )$$ ) of single-photon emission from cadmium selenide quantum dots reveals the particle-size dependence of emission lifetimes. The study also shows that the quality of single-photon emission, as revealed by $$g^{(2)}(0)$$ , reduces with increasing particle-size in the strongly confined regime.
format Article
id doaj-art-3fc86d8a247949c7994200c4326d0c4a
institution OA Journals
issn 2045-2322
language English
publishDate 2025-04-01
publisher Nature Portfolio
record_format Article
series Scientific Reports
spelling doaj-art-3fc86d8a247949c7994200c4326d0c4a2025-08-20T02:19:57ZengNature PortfolioScientific Reports2045-23222025-04-0115111010.1038/s41598-025-99148-9Influence of particle size and dielectric environment on radiative lifetimes of colloidal cadmium selenide single photon emittersV. Manojkumar0Geetha K. Varier1Radhika Vathsan2P. Nandakumar3Department of Physics, Birla Institute of Technology and Science, Pilani, K K Birla Goa CampusDepartment of Physics, Birla Institute of Technology and Science, Pilani, K K Birla Goa CampusDepartment of Physics, Birla Institute of Technology and Science, Pilani, K K Birla Goa CampusDepartment of Physics, Birla Institute of Technology and Science, Pilani, K K Birla Goa CampusAbstract High repetition rate single-photon emitters are essential for all-optical quantum information processing, communications and metrology. The spontaneous emission lifetimes of colloidal cadmium selenide quantum dots are typically of the order of 10 ns, severely limiting their brightness and therefore their potential applications in quantum devices. Here we report on single-photon emission at room temperature with nanosecond lifetime from cadmium selenide quantum dots embedded in a polymer matrix. The study shows that the emission lifetime can be tuned by appropriately choosing the particle size and the dielectric constant of the surrounding medium. The quantum dots are synthesized using a green synthesis protocol and surface passivated using oleic acid. A Hanbury Brown and Twiss setup attached to an in-house constructed confocal microscope is used to efficiently couple and characterize the single-photon emission from an array of quantum dots. Detailed analysis of the second-order correlation function ( $$g^{(2)}(\tau )$$ ) of single-photon emission from cadmium selenide quantum dots reveals the particle-size dependence of emission lifetimes. The study also shows that the quality of single-photon emission, as revealed by $$g^{(2)}(0)$$ , reduces with increasing particle-size in the strongly confined regime.https://doi.org/10.1038/s41598-025-99148-9Colloidal quantum dotsSingle photonsSecond-order correlation functionSpontaneous emission rateCorrelation coefficients
spellingShingle V. Manojkumar
Geetha K. Varier
Radhika Vathsan
P. Nandakumar
Influence of particle size and dielectric environment on radiative lifetimes of colloidal cadmium selenide single photon emitters
Scientific Reports
Colloidal quantum dots
Single photons
Second-order correlation function
Spontaneous emission rate
Correlation coefficients
title Influence of particle size and dielectric environment on radiative lifetimes of colloidal cadmium selenide single photon emitters
title_full Influence of particle size and dielectric environment on radiative lifetimes of colloidal cadmium selenide single photon emitters
title_fullStr Influence of particle size and dielectric environment on radiative lifetimes of colloidal cadmium selenide single photon emitters
title_full_unstemmed Influence of particle size and dielectric environment on radiative lifetimes of colloidal cadmium selenide single photon emitters
title_short Influence of particle size and dielectric environment on radiative lifetimes of colloidal cadmium selenide single photon emitters
title_sort influence of particle size and dielectric environment on radiative lifetimes of colloidal cadmium selenide single photon emitters
topic Colloidal quantum dots
Single photons
Second-order correlation function
Spontaneous emission rate
Correlation coefficients
url https://doi.org/10.1038/s41598-025-99148-9
work_keys_str_mv AT vmanojkumar influenceofparticlesizeanddielectricenvironmentonradiativelifetimesofcolloidalcadmiumselenidesinglephotonemitters
AT geethakvarier influenceofparticlesizeanddielectricenvironmentonradiativelifetimesofcolloidalcadmiumselenidesinglephotonemitters
AT radhikavathsan influenceofparticlesizeanddielectricenvironmentonradiativelifetimesofcolloidalcadmiumselenidesinglephotonemitters
AT pnandakumar influenceofparticlesizeanddielectricenvironmentonradiativelifetimesofcolloidalcadmiumselenidesinglephotonemitters