Optical properties of CdSe nanoparticle films prepared by chemical deposition and sol–gel methods

Lifshitz, Efrat; Dag, I.; Litvin, I.; Hodes, Gary; Gorer, S.; Reisfeld, Renata; Zelner, M.; Minti, H.

doi:10.1016/s0009-2614(98)00283-8

Cited by 148 publications

(113 citation statements)

References 29 publications

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“…Figure 13 shows a representative set of the PL spectra from the film of wurtzite 1.9-nm radius CdSe QDs at 295 K measured at the increased excitation power. The analogous spectra, recorded at two different excitation powers, have been reported also for zinc blend CdSe QDs (R = 2 nm) prepared by chemical solution deposition (CD) [13]. In general, the spectrum of wurtzite CdSe QDs differs from the spectrum of the zinc blend CD CdSe QDs in two aspects:…”

Section: Intensity Excitation Dependence Of the Photoluminescence In Qdsmentioning

confidence: 74%

“…One of the remarkable properties of the PL in CdSe QDs is saturation of the excitonic and deep-level luminescence when more than one exciton is generated per QD [13,19,20,26]. Figure 13 shows a representative set of the PL spectra from the film of wurtzite 1.9-nm radius CdSe QDs at 295 K measured at the increased excitation power.…”

Section: Intensity Excitation Dependence Of the Photoluminescence In Qdsmentioning

confidence: 99%

“…Nevertheless, as it was firstly predicted theoretically, intrinsic deep levels may exist even in well passivated QDs [11,12]. During the last years, specific deep-level luminescence was consistently observed in CdTe and CdSe QDs [13][14][15][16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

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Defects in quantum dots of IIB–VI semiconductors

Babentsov

Сизов

2008

Opto-Electronics Review

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This review discusses the properties of structural defects in quantum dots of IIB–VI semiconductors. A great part of this knowledge has been developed in the last years and combined with the improvement in passivation technologies has contributed significantly to the nanotechnology.In this review we introduced the main characterization methods which are used for the study of defects in the nanoform of semiconductors, presented a short description of how native defects can influence the emission spectra, underlined the restrictions which the Auger and deep-level defect recombination imposes on the excitonic emission. We also highlighted the importance of the defect passivation associated with efficiency and photostability of devices.

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Section: Intensity Excitation Dependence Of the Photoluminescence In Qdsmentioning

confidence: 74%

Section: Intensity Excitation Dependence Of the Photoluminescence In Qdsmentioning

confidence: 99%

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Defects in quantum dots of IIB–VI semiconductors

Babentsov

Сизов

2008

Opto-Electronics Review

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“…Such transition is often called excitonic [5], because an electron-hole pair generated by light absorption is similar to the Wannier-Mott exciton in a bulk crystal. In this paper, attention is paid to the particles with average sizes d= 2.5…2.8 nm, for which the excitonic Bohr radius (a B =5.4 nm) [6] exceeds a particle size. That is why for these particles a strong confinement is realized.…”

Section: Absorption Spectroscopymentioning

confidence: 99%

Influence of the Particle Size on the Optical Properties of CdSe Nanoparticles

Gupta¹,

Ramrakhiani²

2009

TONANOJ

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Monodispersed CdSe nanoparticles with sufficient luminescence intensity have been prepared by chemical method in the presence of mercaptoacetic acid as a capping agent. Cadmium acetate (Cd(Ac) 2 .2H 2 O) and sodium selenosulfate (Na 2 SeSO 3 ) are used as a cadmium and selenium sources respectively. The resulting nanocrystallites have been characterized by X-Ray Diffraction, UV-Vis absorption spectra and photoluminescence (PL) spectroscopy. The particle size was estimated from broadening of XRD peak using Scherrer's formula and also from effective band gap by absorption peak using effective mass approximation model. The size obtained from XRD and absorption peaks are in agreement with each other. It is observed that the samples consist of separated, well-defined spherical particles and show a small size distribution as well as a characteristic blue shift due to quantum confinement in their optical absorption as well as PL spectra. It is found that the size of CdSe nanoparticles decreases, as the concentration of capping agent is increased. The intensity of PL peak increases and the peak shift towards blue region as the particle size is reduced. The sharp PL spectra also indicate that the nanoparticles are monodispersed.

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“…The fabrication of nanometer-sized crystallites can be achieved by growth in colloidal solutions (Murray et al, 1993;Crouch et al, 2003), on surfaces in vacuum deposition processes (Lee et al, 2006;Schü ler et al, 1999Schü ler et al, , 2001, by electron beam lithography (Ishikawa et al, 2000), or by sol-gel techniques (Parvathy et al, 1997;Lifshitz et al, 1998). Often core-shell structures are used to passivate the surfaces of the nanocrystals (e.g.…”

Section: Introductionmentioning

confidence: 99%

Quantum dot containing nanocomposite thin films for photoluminescent solar concentrators

et al. 2007

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Silicon oxide films containing CdS quantum dots have been deposited on glass substrates by a sol-gel dip-coating process. Hereby the CdS nanocrystals are grown during the thermal annealing step following the dip-coating procedure. Total hemispherical transmittance and reflectance measurements were carried out by means of a spectrophotometer coupled to an integrating sphere. For CdS-rich films, an absorption edge at photon energies in the vicinity of the band gap value of bulk CdS is observed. For lower CdS concentrations, the absorption edge shifts to higher photon energies, as expected for increasing quantum confinement. The samples show visible photoluminescence which is concentrated by total internal reflection and emitted at the edges of the substrate. The edge emission has been characterized by angle-dependent photoluminescent (PL) spectroscopy. Information on the lateral energy transport within the sample can be extracted from spectra obtained under spatial variation of the spot of excitation. The color of the photoluminescence can be tuned by varying the annealing temperature which governs crystal growth and thus the cluster size distribution. The characteristic features observed in the PL spectra clearly exhibit a blueshift for lower annealing temperatures, confirming the presence of quantum size effects.Advantages of the proposed concept of quantum dot containing coatings on glass panes for photoluminescent solar concentrators are the high potential for low-cost fabrication on the large scale and the suitability for architectural integration.

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Optical properties of CdSe nanoparticle films prepared by chemical deposition and sol–gel methods

Cited by 148 publications

References 29 publications

Defects in quantum dots of IIB–VI semiconductors

Defects in quantum dots of IIB–VI semiconductors

Influence of the Particle Size on the Optical Properties of CdSe Nanoparticles

Quantum dot containing nanocomposite thin films for photoluminescent solar concentrators

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