Temperature-Dependent Excitonic Photoluminescence and Nonlinear Absorption of CdTe Nanocrystal/Polyvinyl Alcohol Films

The temperature dependence of the excitonic photoluminescence (PL) and nonlinear absorption characteristics of CdTe nanocrystals (NCs)/polyvinyl alcohol (PVA) film are investigated using steady-state/time-resolved PL spectroscopy and Z-scan methods. The excitonic PL peaks of CdTe NCs can be observed...

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Main Authors: Qing Chang, Jingrong Sui, Zhijun Chai, Wenzhi Wu
Format: Article
Language:English
Published: MDPI AG 2021-07-01
Series:Nanomaterials
Subjects:
Online Access:https://www.mdpi.com/2079-4991/11/7/1761
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author Qing Chang
Jingrong Sui
Zhijun Chai
Wenzhi Wu
author_facet Qing Chang
Jingrong Sui
Zhijun Chai
Wenzhi Wu
author_sort Qing Chang
collection DOAJ
description The temperature dependence of the excitonic photoluminescence (PL) and nonlinear absorption characteristics of CdTe nanocrystals (NCs)/polyvinyl alcohol (PVA) film are investigated using steady-state/time-resolved PL spectroscopy and Z-scan methods. The excitonic PL peaks of CdTe NCs can be observed at the wavelengths from 560 to 670 nm, with size changes from 2.1 to 3.9 nm. From the temperature-dependent PL spectra, the smaller photon energy of the PL emission peak, the rapidly decreasing PL intensity, and the wider linewidth are observed with increasing temperature from 80 to 300 K. It is revealed that the excitonic PL is composed of both trapped state and band-edge excitonic state, which presents biexponential fitting dynamics. The short-lived species is due to the surface-trapped state recombination in NCs, which has a photogenerated trapped channel and a time-resolved peak shift. The species with a long-lived lifetime is ascribed to the intrinsic excitonic recombination. Through the femtosecond Z-scan method, the nonlinear absorption coefficient becomes smaller with the increase in the size of the NCs. The optical properties of the CdTe NC/PVA film show the potential of II-VI traditional NCs as display and luminescent materials that can utilize the combination of excitonic PL and nonlinear absorption for expanded functionality.
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spelling doaj.art-71e7464e172a4fa4907865639f9e5c692023-11-22T04:33:30ZengMDPI AGNanomaterials2079-49912021-07-01117176110.3390/nano11071761Temperature-Dependent Excitonic Photoluminescence and Nonlinear Absorption of CdTe Nanocrystal/Polyvinyl Alcohol FilmsQing Chang0Jingrong Sui1Zhijun Chai2Wenzhi Wu3College of Media Engineering, Communication University of Zhejiang, Hangzhou 310018, ChinaSchool of Electronic Engineering, Heilongjiang University, Harbin 150080, ChinaSchool of Electronic Engineering, Heilongjiang University, Harbin 150080, ChinaSchool of Electronic Engineering, Heilongjiang University, Harbin 150080, ChinaThe temperature dependence of the excitonic photoluminescence (PL) and nonlinear absorption characteristics of CdTe nanocrystals (NCs)/polyvinyl alcohol (PVA) film are investigated using steady-state/time-resolved PL spectroscopy and Z-scan methods. The excitonic PL peaks of CdTe NCs can be observed at the wavelengths from 560 to 670 nm, with size changes from 2.1 to 3.9 nm. From the temperature-dependent PL spectra, the smaller photon energy of the PL emission peak, the rapidly decreasing PL intensity, and the wider linewidth are observed with increasing temperature from 80 to 300 K. It is revealed that the excitonic PL is composed of both trapped state and band-edge excitonic state, which presents biexponential fitting dynamics. The short-lived species is due to the surface-trapped state recombination in NCs, which has a photogenerated trapped channel and a time-resolved peak shift. The species with a long-lived lifetime is ascribed to the intrinsic excitonic recombination. Through the femtosecond Z-scan method, the nonlinear absorption coefficient becomes smaller with the increase in the size of the NCs. The optical properties of the CdTe NC/PVA film show the potential of II-VI traditional NCs as display and luminescent materials that can utilize the combination of excitonic PL and nonlinear absorption for expanded functionality.https://www.mdpi.com/2079-4991/11/7/1761CdTe nanocrystalsphotoluminescencetemperature-dependentband-edge excitonnonlinear absorption
spellingShingle Qing Chang
Jingrong Sui
Zhijun Chai
Wenzhi Wu
Temperature-Dependent Excitonic Photoluminescence and Nonlinear Absorption of CdTe Nanocrystal/Polyvinyl Alcohol Films
Nanomaterials
CdTe nanocrystals
photoluminescence
temperature-dependent
band-edge exciton
nonlinear absorption
title Temperature-Dependent Excitonic Photoluminescence and Nonlinear Absorption of CdTe Nanocrystal/Polyvinyl Alcohol Films
title_full Temperature-Dependent Excitonic Photoluminescence and Nonlinear Absorption of CdTe Nanocrystal/Polyvinyl Alcohol Films
title_fullStr Temperature-Dependent Excitonic Photoluminescence and Nonlinear Absorption of CdTe Nanocrystal/Polyvinyl Alcohol Films
title_full_unstemmed Temperature-Dependent Excitonic Photoluminescence and Nonlinear Absorption of CdTe Nanocrystal/Polyvinyl Alcohol Films
title_short Temperature-Dependent Excitonic Photoluminescence and Nonlinear Absorption of CdTe Nanocrystal/Polyvinyl Alcohol Films
title_sort temperature dependent excitonic photoluminescence and nonlinear absorption of cdte nanocrystal polyvinyl alcohol films
topic CdTe nanocrystals
photoluminescence
temperature-dependent
band-edge exciton
nonlinear absorption
url https://www.mdpi.com/2079-4991/11/7/1761
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AT jingrongsui temperaturedependentexcitonicphotoluminescenceandnonlinearabsorptionofcdtenanocrystalpolyvinylalcoholfilms
AT zhijunchai temperaturedependentexcitonicphotoluminescenceandnonlinearabsorptionofcdtenanocrystalpolyvinylalcoholfilms
AT wenzhiwu temperaturedependentexcitonicphotoluminescenceandnonlinearabsorptionofcdtenanocrystalpolyvinylalcoholfilms