Crystal field, phonon coupling and emission shift of Mn2+ in ZnS:Mn nanoparticles

Chen, Wei; Sammynaiken, Ramaswami; Huang, Yining; Malm, Jan‐Olle; Wallenberg, L. Reine; Bovin, Jan‐Olov; Zwiller, Valéry; Kotov, Nicholas A.

doi:10.1063/1.1332795

Cited by 203 publications

(177 citation statements)

References 43 publications

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“…The relation E Stokes = (2S À 1) ho is used in many reports, 1,[12][13][14][15][16][17][18][19] while other works use the alternative relation E Stokes = 2S ho (ref. [20][21][22][23][24], or are ambiguous about it. 25 New insights in the relation between the experimentally observed Stokes shift and the Huang-Rhys parameter, with the aim to resolve this ambiguity, can be realized using simulations.…”

Section: Introductionmentioning

confidence: 99%

Resolving the ambiguity in the relation between Stokes shift and Huang–Rhys parameter

Jong

Seijo

Meijerink

et al. 2015

Phys. Chem. Chem. Phys.

255

235

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Electronic transitions in luminescent molecules or centers in crystals couple to vibrations. This results in broadening of absorption and emission bands, as well as in the occurence of a Stokes shift E Stokes . In principle, one can derive from E Stokes the Huang-Rhys parameter S, which describes the microscopic details of the vibrational coupling and can be related to the equilibrium position offset DQ e between the ground state and excited state. The commonly used textbook relations E Stokes = (2S À 1) ho and E Stokes = 2S ho are only approximately valid. In this paper we investigate how E Stokes is related to S, taking into account the effects of a finite temperature. We show that in different ranges of temperature, different approximate relations between E Stokes and S are appropriate. Moreover, we demonstrate that the difference between the barycenters of absorption and emission bands can be used to determine S in an unambiguous way.The position of the barycenter is, contrary to the Stokes shift, unaffected by temperature.

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Section: Introductionmentioning

confidence: 99%

Resolving the ambiguity in the relation between Stokes shift and Huang–Rhys parameter

Jong

Seijo

Meijerink

et al. 2015

Phys. Chem. Chem. Phys.

255

235

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“…O uso do ZnO como material fotocatalisador para a degradação de poluentes ambientais tem sido vantajoso em relação a outros materiais devido à sua natureza não-tóxica, seu baixo custo e alta reatividade, 17,18 como também ocorre para o dióxido de titânio. O óxido de zinco tem sido sintetizado por vários métodos, tais como sol-gel, 19,20 de estado sólido, 21,22 de condensação da fase gasosa 23 e método químico de precipitação em fase líquida. 24,25 O estudo do efeito de vários fotocatalisadores na descolorização e degradação do azo corante Reactive Yellow (RY14) em solução aquosa revelou a seguinte ordem de reatividade: ZnO > TiO 2 -P25 > TiO 2 (anatase).…”

Section: Introductionunclassified

Nanocompósitos semicondutores ZnO/TiO2: testes fotocatalíticos

Silva¹,

Magalhães²,

Sansiviero³

2010

Quím. Nova

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Recebido em 8/1/09; aceito em 15/6/09; publicado na web em 25/11/09 ZnO/TiO 2 SEMICONDUCTOR NANOCOMPOSITES. PHOTOCATALYTIC TESTS. Titanium dioxide is an efficient photocatalist, being possible to improve its efficiency with better charge separation which occurs when it is coupled with other semiconductors. Nanometric particles of ZnO were used to impregnate TiO 2 P25 in order to optimize its photocatalytic properties. ZnO/TiO 2 composites were obtained at different proportions and were characterized by X-ray diffraction (XRD), micro-Raman and diffuse reflectance spectroscopies, measurement of surface area (BET) and scanning electron microscopy (SEM). Raman spectroscopy data revealed a change on the TiO 2 surface due the presence of ZnO which was observed by an enlargement of TiO 2 peaks and a change on the relation rate between anatase and rutile phases of the composites. The photodegradation of azo-dye Drimaren red revealed better efficiency for ZnO/TiO 2 3% nanocomposite and for ZnO pure.Keywords: semiconductor nanocomposites; photocatalysis, Raman spectroscopy. INTRODUÇÃOO dióxido de titânio é um semicondutor (E gap = 3,2 eV) que se encontra principalmente na forma de três estruturas cristalinas, anatásio, rutilo e brokita. A forma anatásio é aquela que apresenta maior atividade fotocatalítica, 1,2 sendo grandemente usado como fotocatalisador devido à sua alta eficiência e baixo custo. Algumas aplicações de grande relevância envolvendo o semicondutor TiO 2 são: fotocatálises assistidas por semicondutor para produzir combustíveis, tais como hidrogênio e, células solares baseadas em nanoestruturas de semicondutor. 3 O princípio de funcionamento do TiO 2 como fotocatalisador baseia-se na geração do par elétron-lacuna positiva, através da absorção de energia. 4 A luz UV é a fonte de energia mais comumente empregada. Sob irradiação, elétrons da banda de valência recebem energia suficiente para transpor a lacuna de energia do TiO 2 e podem, desta forma, serem transferidos para a banda de condução. As lacunas positivas são fortes agentes oxidantes e são responsáveis pela mineralização de vários compostos orgânicos. 5 Nos últimos 30 anos, vários estudos têm sido realizados para investigar as possíveis aplicações do TiO 2 como fotocatalisador. A maior parte desses estudos está concentrada no tratamento de sistemas aquosos contaminados por poluentes orgânicos considerados potencialmente tóxicos. 6 Materiais semicondutores nanoparticulados têm algumas propriedades peculiares e a elucidação destas propriedades tem levado à descoberta de diferentes campos da ciência e da tecnologia. 7 Nanopartículas de ZnO recentemente têm recebido grande atenção devido a uma variedade de aplicações tais como, absorção no UV, desodorização e tratamento antibacteriano. 8,9 O semicondutor ZnO tem um bandgap de 3,37 eV em temperatura ambiente e é um dos mais importantes materiais inorgânicos, com propriedades catalítica, 10,11 elétrica, 12,13 opticoeletrônica, 14,15 e fotoquímica, 16 o que tem estimulado cada vez mais a ampla investigação em...

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“…The PLE and PL spectra of ZnS:Mn/PVP nanoparticles excited by different excitation wavelengths showed that in these nanoparticles there exhibited two excitation mechanisms: the indirect excitation through ZnS host and the direct excitation of 3d-electrons of Mn 2+ cations [15]. The excitation by 344 nm radiation with photon energy near the band gap energy of ZnS is mainly the indirect excitation.…”

Section: Iii3 the Influence Of Pvp On Absorption And Radiation Tranmentioning

confidence: 99%

“…6(a)). These bands could be assigned to the absorption transitions of 3d 5 electrons from 6 A 1 ( 6 S) ground state to 4 E( 4 D), 4 T 2 ( 4 D), 4 A 1 ( 4 G)-4 E( 4 G) and 4 T 2 ( 4 G) excited states of Mn 2+ cations in ZnS host lattice, respectively [15]. For PVP-capped ZnS:Mn nanoparticles with mass from 0.3 to 0.8 g, the intensity of these bands increased and achieved the maximum at mass equal 0.7 g (see Fig.…”

Section: Iii3 the Influence Of Pvp On Absorption And Radiation Tranmentioning

confidence: 99%

Influence of Polyvinyl Pyrrolidone on Absorption and Radiation Transitions of Mn\(^{2 + }\) ions in Mn-doped ZnS Nanoparticles

Thai¹,

Thang²,

Ben³

et al. 2016

Comm. in Phys.

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Abstract. ZnS:Mn nanoparticles were synthesized by co-precipitation method from the precursors solutions of 0.1M Zn(CH 3 COO) 2 , Na 2 S and Mn(CH 3 COO) 2 then were capped with polyvinyl pyrrolidone. The XRD patterns showed that the ZnS:Mn nanoparticles possessed the T 2 d − F43m cubic structure with the average crystallite size of several nanometers. At 300 K, the obtained photoluminescence spectra showed only a wide yellow-orange band centered at 603 nm, which should be attributed to the radiation transition of [ 4 T 1 ( 4 G)→ 6 A 1 ( 6 S)] of Mn 2+ (3d 5 ) cations in the ZnS matrix. The excitation spectra recorded at 300 K on the other hand featured a strong photoluminescence band around 344 nm, which were assigned to the near band-edge absorption transition of ZnS host lattice, in addition with three weaker bands relating to the absorption transitions of468 nm, and [ 6 A 1 ( 6 S) → 4 T 2 ( 4 G)]: 492 nm of Mn 2+ (3d 5 ) cations. It was shown that the capping affected only the intensities of emissions bands.

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Crystal field, phonon coupling and emission shift of Mn2+ in ZnS:Mn nanoparticles

Cited by 203 publications

References 43 publications

Resolving the ambiguity in the relation between Stokes shift and Huang–Rhys parameter

Resolving the ambiguity in the relation between Stokes shift and Huang–Rhys parameter

Nanocompósitos semicondutores ZnO/TiO2: testes fotocatalíticos

Influence of Polyvinyl Pyrrolidone on Absorption and Radiation Transitions of Mn\(^{2 + }\) ions in Mn-doped ZnS Nanoparticles

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