Role of surface charge distribution on band-structure and optical properties of silicon nanocrystals

Chia-Ching Huang, Hui Nie, Jos M.J. Paulusse, Jonathan Wilbrink, Katerina Dohnalová

Research output: Contribution to conferencePosterOther research output

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Abstract

Quantum confinement effects in silicon nanostructures have been studied over the past 3 decades [1], with aim to convert silicon into direct bandgap-like semiconductor for applications as efficient light emitters, even amplifiers and lasers. We have shown that slightly electronegative ligands on the surface of silicon quantum dot (Si-QD) and/or varying electrostatic field from the environment manipulates the electronic density inside the Si-QD’s core, ultimately resulting in an indirect-to-direct bandgap conversion [2,3]. To test the role of charge distribution induced by ligands and environment experimentally, we synthesize colloidal Si-QDs capped by butyl chains using oxygen-free wet chemical method [3] and introduce two terminations, amine (-NH2) and carboxylic acid (-COOH). Si-QDs are dispersed in aqueous solutions of varying pH. The push-pull effect on the electronic wave-functions translates into changes in band-gap (emission spectrum and absorption band-edge) and emission lifetime. Results are interpreted and discussed within the frame of our theoretical simulations by tight binding and DFT.
Original languageEnglish
Number of pages1
Publication statusPublished - 2017
EventE-MRS spring meeting 2017 - Strasbourg, France
Duration: 22 May 201726 May 2017

Conference

ConferenceE-MRS spring meeting 2017
CountryFrance
CityStrasbourg
Period22/05/1726/05/17

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charge distribution
nanocrystals
optical properties
silicon
ligands
electronics
carboxylic acids
amines
emitters
emission spectra
amplifiers
quantum dots
wave functions
aqueous solutions
absorption spectra
life (durability)
electric fields
oxygen
lasers
simulation

Cite this

Huang, C-C., Nie, H., Paulusse, J. M. J., Wilbrink, J., & Dohnalová, K. (2017). Role of surface charge distribution on band-structure and optical properties of silicon nanocrystals. Poster session presented at E-MRS spring meeting 2017, Strasbourg, France.
Huang, Chia-Ching ; Nie, Hui ; Paulusse, Jos M.J. ; Wilbrink, Jonathan ; Dohnalová, Katerina. / Role of surface charge distribution on band-structure and optical properties of silicon nanocrystals. Poster session presented at E-MRS spring meeting 2017, Strasbourg, France.1 p.
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title = "Role of surface charge distribution on band-structure and optical properties of silicon nanocrystals",
abstract = "Quantum confinement effects in silicon nanostructures have been studied over the past 3 decades [1], with aim to convert silicon into direct bandgap-like semiconductor for applications as efficient light emitters, even amplifiers and lasers. We have shown that slightly electronegative ligands on the surface of silicon quantum dot (Si-QD) and/or varying electrostatic field from the environment manipulates the electronic density inside the Si-QD’s core, ultimately resulting in an indirect-to-direct bandgap conversion [2,3]. To test the role of charge distribution induced by ligands and environment experimentally, we synthesize colloidal Si-QDs capped by butyl chains using oxygen-free wet chemical method [3] and introduce two terminations, amine (-NH2) and carboxylic acid (-COOH). Si-QDs are dispersed in aqueous solutions of varying pH. The push-pull effect on the electronic wave-functions translates into changes in band-gap (emission spectrum and absorption band-edge) and emission lifetime. Results are interpreted and discussed within the frame of our theoretical simulations by tight binding and DFT.",
author = "Chia-Ching Huang and Hui Nie and Paulusse, {Jos M.J.} and Jonathan Wilbrink and Katerina Dohnalov{\'a}",
year = "2017",
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note = "E-MRS spring meeting 2017 ; Conference date: 22-05-2017 Through 26-05-2017",

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Huang, C-C, Nie, H, Paulusse, JMJ, Wilbrink, J & Dohnalová, K 2017, 'Role of surface charge distribution on band-structure and optical properties of silicon nanocrystals' E-MRS spring meeting 2017, Strasbourg, France, 22/05/17 - 26/05/17, .

Role of surface charge distribution on band-structure and optical properties of silicon nanocrystals. / Huang, Chia-Ching; Nie, Hui ; Paulusse, Jos M.J.; Wilbrink, Jonathan; Dohnalová, Katerina.

2017. Poster session presented at E-MRS spring meeting 2017, Strasbourg, France.

Research output: Contribution to conferencePosterOther research output

TY - CONF

T1 - Role of surface charge distribution on band-structure and optical properties of silicon nanocrystals

AU - Huang, Chia-Ching

AU - Nie, Hui

AU - Paulusse, Jos M.J.

AU - Wilbrink, Jonathan

AU - Dohnalová, Katerina

PY - 2017

Y1 - 2017

N2 - Quantum confinement effects in silicon nanostructures have been studied over the past 3 decades [1], with aim to convert silicon into direct bandgap-like semiconductor for applications as efficient light emitters, even amplifiers and lasers. We have shown that slightly electronegative ligands on the surface of silicon quantum dot (Si-QD) and/or varying electrostatic field from the environment manipulates the electronic density inside the Si-QD’s core, ultimately resulting in an indirect-to-direct bandgap conversion [2,3]. To test the role of charge distribution induced by ligands and environment experimentally, we synthesize colloidal Si-QDs capped by butyl chains using oxygen-free wet chemical method [3] and introduce two terminations, amine (-NH2) and carboxylic acid (-COOH). Si-QDs are dispersed in aqueous solutions of varying pH. The push-pull effect on the electronic wave-functions translates into changes in band-gap (emission spectrum and absorption band-edge) and emission lifetime. Results are interpreted and discussed within the frame of our theoretical simulations by tight binding and DFT.

AB - Quantum confinement effects in silicon nanostructures have been studied over the past 3 decades [1], with aim to convert silicon into direct bandgap-like semiconductor for applications as efficient light emitters, even amplifiers and lasers. We have shown that slightly electronegative ligands on the surface of silicon quantum dot (Si-QD) and/or varying electrostatic field from the environment manipulates the electronic density inside the Si-QD’s core, ultimately resulting in an indirect-to-direct bandgap conversion [2,3]. To test the role of charge distribution induced by ligands and environment experimentally, we synthesize colloidal Si-QDs capped by butyl chains using oxygen-free wet chemical method [3] and introduce two terminations, amine (-NH2) and carboxylic acid (-COOH). Si-QDs are dispersed in aqueous solutions of varying pH. The push-pull effect on the electronic wave-functions translates into changes in band-gap (emission spectrum and absorption band-edge) and emission lifetime. Results are interpreted and discussed within the frame of our theoretical simulations by tight binding and DFT.

M3 - Poster

ER -

Huang C-C, Nie H, Paulusse JMJ, Wilbrink J, Dohnalová K. Role of surface charge distribution on band-structure and optical properties of silicon nanocrystals. 2017. Poster session presented at E-MRS spring meeting 2017, Strasbourg, France.