Effect of size and shape on electronic and optical properties of CdSe quantum dots

In this paper, we used the 8-band k$\cdot$p model with valence force field considerations to investigate the effect of size and shape on electronic and optical properties of cadmium selenide quantum dots. Major factors related to their properties including band mixing probabilities, spatial charge d...

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Main Authors: Liu, Yincheng, Bose, Sumanta, Fan, Weijun
Other Authors: School of Computer Science and Engineering
Format: Article
Language:English
Published: 2020
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Online Access:https://hdl.handle.net/10356/137746
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1377462020-04-13T06:01:26Z Effect of size and shape on electronic and optical properties of CdSe quantum dots Liu, Yincheng Bose, Sumanta Fan, Weijun School of Computer Science and Engineering Physics - Materials Science Physics - Materials Science Physics - Mesoscopic Systems and Quantum Hall Effect physics.app-ph Physics - Optics Quantum Physics Science::Physics 8-Band k · p Method CdSe Quantum Dots In this paper, we used the 8-band k$\cdot$p model with valence force field considerations to investigate the effect of size and shape on electronic and optical properties of cadmium selenide quantum dots. Major factors related to their properties including band mixing probabilities, spatial charge distributions, transition matrix elements and Fermi factors were studied. Volumetrically larger CdSe dots were found to have smaller band-gaps but higher transition matrix elements and Fermi factors. The maximum optical gain for dots was observed to have an initially positive and then negative correlation with their real-space size as a result of combined effects of various factors. For the shape effects, cubic dots were found to have smaller band-gaps, Fermi factors and transition matrix elements than spherical dots due to higher level of asymmetry and different surface effects. Consequently, cubic dots have lower emission energy, smaller amplification. The occurrence of near E1-H1 transition broadens the gain spectrum of cubic dots. Cubic and spherical dots are both proven to be promising candidates for optical devices under visible range. We have demonstrated that size and shape change could both effectively alter the properties of quantum dots and therefore recommend consideration of both when optimizing the performance for any desired application. 2020-04-13T06:01:26Z 2020-04-13T06:01:26Z 2018 Journal Article Liu, Y., Bose, S., & Fan, W. (2018). Effect of size and shape on electronic and optical properties of CdSe quantum dots. Optik, 155, 242-250. doi:10.1016/j.ijleo.2017.10.165 0030-4026 https://hdl.handle.net/10356/137746 10.1016/j.ijleo.2017.10.165 2-s2.0-85032949151 155 242 250 en Optik © 2017 Elsevier GmbH. All rights reserved.
institution Nanyang Technological University
building NTU Library
country Singapore
collection DR-NTU
language English
topic Physics - Materials Science
Physics - Materials Science
Physics - Mesoscopic Systems and Quantum Hall Effect
physics.app-ph
Physics - Optics
Quantum Physics
Science::Physics
8-Band k · p Method
CdSe Quantum Dots
spellingShingle Physics - Materials Science
Physics - Materials Science
Physics - Mesoscopic Systems and Quantum Hall Effect
physics.app-ph
Physics - Optics
Quantum Physics
Science::Physics
8-Band k · p Method
CdSe Quantum Dots
Liu, Yincheng
Bose, Sumanta
Fan, Weijun
Effect of size and shape on electronic and optical properties of CdSe quantum dots
description In this paper, we used the 8-band k$\cdot$p model with valence force field considerations to investigate the effect of size and shape on electronic and optical properties of cadmium selenide quantum dots. Major factors related to their properties including band mixing probabilities, spatial charge distributions, transition matrix elements and Fermi factors were studied. Volumetrically larger CdSe dots were found to have smaller band-gaps but higher transition matrix elements and Fermi factors. The maximum optical gain for dots was observed to have an initially positive and then negative correlation with their real-space size as a result of combined effects of various factors. For the shape effects, cubic dots were found to have smaller band-gaps, Fermi factors and transition matrix elements than spherical dots due to higher level of asymmetry and different surface effects. Consequently, cubic dots have lower emission energy, smaller amplification. The occurrence of near E1-H1 transition broadens the gain spectrum of cubic dots. Cubic and spherical dots are both proven to be promising candidates for optical devices under visible range. We have demonstrated that size and shape change could both effectively alter the properties of quantum dots and therefore recommend consideration of both when optimizing the performance for any desired application.
author2 School of Computer Science and Engineering
author_facet School of Computer Science and Engineering
Liu, Yincheng
Bose, Sumanta
Fan, Weijun
format Article
author Liu, Yincheng
Bose, Sumanta
Fan, Weijun
author_sort Liu, Yincheng
title Effect of size and shape on electronic and optical properties of CdSe quantum dots
title_short Effect of size and shape on electronic and optical properties of CdSe quantum dots
title_full Effect of size and shape on electronic and optical properties of CdSe quantum dots
title_fullStr Effect of size and shape on electronic and optical properties of CdSe quantum dots
title_full_unstemmed Effect of size and shape on electronic and optical properties of CdSe quantum dots
title_sort effect of size and shape on electronic and optical properties of cdse quantum dots
publishDate 2020
url https://hdl.handle.net/10356/137746
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