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Search for "absorption coefficient" in Full Text gives 105 result(s) in Beilstein Journal of Nanotechnology.

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

  • Viet Van Pham,
  • Hong-Huy Tran,
  • Thao Kim Truong and
  • Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

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  • increasing film thickness [45]. Zhou et al. indicated that the direct bandgap transition of SnO2 has an absorption coefficient α and the optical bandgap (Eg) can be determined by the calculation of α(hν)2 ∝ (hν − Eg)1/2/hν, and the plot of α(hν)2 vs photon energy hν, respectively. For example, the bandgap of
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Published 21 Jan 2022

First-principles study of the structural, optoelectronic and thermophysical properties of the π-SnSe for thermoelectric applications

  • Muhammad Atif Sattar,
  • Najwa Al Bouzieh,
  • Maamar Benkraouda and
  • Noureddine Amrane

Beilstein J. Nanotechnol. 2021, 12, 1101–1114, doi:10.3762/bjnano.12.82

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  • [73]: where P and ω represent the principal value and angular frequency, respectively. The other optical parameters, such as the absorption coefficient α(ω), energy loss function L(ω), refractive index n(ω), extinction coefficient K(ω), reflectivity R(ω), and conductivity σ(ω) can be easily obtained
  • that two important peaks (α and β) are located in the visible region. Beyond the β peak, ε2(ω) shows a decreasing trend at higher energies. The absorption coefficient α(ω) is presented in Figure 11c as a function of photon energy. The absorption coefficient demonstrates all the information of the
  • α(ω) π-SnSe is zero until the photon energy is lower as compared to its energy bandgap of 1.41 eV. After this energy, the π-SnSe alloy displays a sharp increase of absorption coefficient α(ω) up to 139.6 104/cm at 6 eV. After this energy value, α(ω) starts to decrease with the increase in photon
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Published 05 Oct 2021

Revealing the formation mechanism and band gap tuning of Sb2S3 nanoparticles

  • Maximilian Joschko,
  • Franck Yvan Fotue Wafo,
  • Christina Malsi,
  • Danilo Kisić,
  • Ivana Validžić and
  • Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 1021–1033, doi:10.3762/bjnano.12.76

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  • are several requirements for materials to be eligible for application in the field of photovoltaics, such as high absorption performance, nontoxicity, abundance, efficiency, and low cost. As a semiconductor with a low band gap and a high absorption coefficient, antimony(III) sulfide (Sb2S3) has become
  • receive the band gap values of the material [37][38]. As shown in Equation 1, the absorption coefficient α is expressed by the Planck constant h, the photon frequency ν, a constant B, which Davis and Mott described as the magnitude of the optical absorption constant [38], and a transition factor γ: The
  • transition factor γ depends on the type of the band gap transition. It equals 1/2 for a direct allowed transition and 2 for an indirect allowed transition. For reflectance data, α is expressed by the Kubelka–Munk function F(R∞) (Equation 2), which is the quotient of the absorption coefficient k and the
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Published 10 Sep 2021

9.1% efficient zinc oxide/silicon solar cells on a 50 μm thick Si absorber

  • Rafal Pietruszka,
  • Bartlomiej S. Witkowski,
  • Monika Ozga,
  • Katarzyna Gwozdz,
  • Ewa Placzek-Popko and
  • Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 766–774, doi:10.3762/bjnano.12.60

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  • junction where they are effectively separated or recombined at the rear contact. Generally, in the infrared region absorption coefficient is low for silicon substrates [20]. Moreover, the electron–hole pairs generated deep in a cell are strongly attracted by the rear contact, and these pairs recombine
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Published 21 Jul 2021

Impact of GaAs(100) surface preparation on EQE of AZO/Al2O3/p-GaAs photovoltaic structures

  • Piotr Caban,
  • Rafał Pietruszka,
  • Jarosław Kaszewski,
  • Monika Ożga,
  • Bartłomiej S. Witkowski,
  • Krzysztof Kopalko,
  • Piotr Kuźmiuk,
  • Katarzyna Gwóźdź,
  • Ewa Płaczek-Popko,
  • Krystyna Lawniczak-Jablonska and
  • Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 578–592, doi:10.3762/bjnano.12.48

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  • the Kubelka–Munk function, α is the absorption coefficient, s is the scattering factor and R is the reflectance [46]. After a linear extrapolation within the plot of [F(R)·hν]2 as a function of hν of the relevant area of linear increase, an intersection point with the abscissa was determined for each
  • ), where α is the energy-dependent absorption coefficient, B is the constant and Eg is the bandgap energy [47]. Within the obtained plot, the relevant area of rapid linear absorbance growth was extrapolated accordingly, pointing the value of 3.23 eV (the crossing point with the abscissa) as the bandgap of
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Published 28 Jun 2021

Structural and optical characteristics determined by the sputtering deposition conditions of oxide thin films

  • Petronela Prepelita,
  • Florin Garoi and
  • Valentin Craciun

Beilstein J. Nanotechnol. 2021, 12, 354–365, doi:10.3762/bjnano.12.29

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  • thickness. The optical constants (i.e., the refractive index n, the extinction coefficient k, and the absorption coefficient α) of the SiO2 and ZnO oxide films were determined from the transmission spectra recorded in the range of 190–2500 nm by using the Swanepoel method, while the energy bandgap was
  • ZnO thin films, between the extinction coefficient, k, (Figure 9) and the absorption coefficient, α, there is this following relation: where λ is the wavelength. We determined the optical bandgap, corresponding to the direct optical transitions, by extrapolating the linear portion of the dependency
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Published 19 Apr 2021

Unravelling the interfacial interaction in mesoporous SiO2@nickel phyllosilicate/TiO2 core–shell nanostructures for photocatalytic activity

  • Bridget K. Mutuma,
  • Xiluva Mathebula,
  • Isaac Nongwe,
  • Bonakele P. Mtolo,
  • Boitumelo J. Matsoso,
  • Rudolph Erasmus,
  • Zikhona Tetana and
  • Neil J. Coville

Beilstein J. Nanotechnol. 2020, 11, 1834–1846, doi:10.3762/bjnano.11.165

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  • ]: where F(R) is the Kubelka–Munk function, α is the absorption coefficient and S is the scattering coefficient (n = 2 or 0.5 for direct or indirect transitions, respectively). The functional groups on mSiO2@NiPS and mSiO2@NiPS/TiO2 composites were determined using a Bruker Tensor 27 Fourier-transform
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Published 09 Dec 2020

Absorption and photoconductivity spectra of amorphous multilayer structures

  • Oxana Iaseniuc and
  • Mihail Iovu

Beilstein J. Nanotechnol. 2020, 11, 1757–1763, doi:10.3762/bjnano.11.158

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  • visible region, in contrast to the other thin-film structures (curve 4). Figure 2 shows the function log α = f(hν) of the absorption coefficient for single amorphous layers and for the amorphous HS. The absorption coefficient α for each layer can be calculated using the expression: The absorption
  • coefficient α of each separate component layer is higher than that of the HS. The highest value of the absorption coefficient α was obtained for the amorphous film of Ge0.30As0.04S0.66 with the smallest thickness of d ≈ 200 nm. The amorphous structures described above with two Al electrodes, of which the
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Published 20 Nov 2020

A few-layer graphene/chlorin e6 hybrid nanomaterial and its application in photodynamic therapy against Candida albicans

  • Selene Acosta,
  • Carlos Moreno-Aguilar,
  • Dania Hernández-Sánchez,
  • Beatriz Morales-Cruzado,
  • Erick Sarmiento-Gomez,
  • Carla Bittencourt,
  • Luis Octavio Sánchez-Vargas and
  • Mildred Quintana

Beilstein J. Nanotechnol. 2020, 11, 1054–1061, doi:10.3762/bjnano.11.90

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  • visible light, and also should have a high absorption coefficient at a wavelength that penetrates cellular tissue [4]. In the visible electromagnetic spectrum, red light has the largest depth penetration into biological tissue [6][7]. Among different photosensitizers, porphyrins are heterocyclic molecules
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Published 17 Jul 2020

Excitonic and electronic transitions in Me–Sb2Se3 structures

  • Nicolae N. Syrbu,
  • Victor V. Zalamai,
  • Ivan G. Stamov and
  • Stepan I. Beril

Beilstein J. Nanotechnol. 2020, 11, 1045–1053, doi:10.3762/bjnano.11.89

Graphical Abstract
  • triselenide; band structure; excitons; optical spectroscopy; reflection and absorption spectra; Introduction Antimony selenide (Sb2Se3) is an inorganic semiconductor compound with interesting photoelectric properties. This material has a high absorption coefficient (≈105 cm−1) in the region of maximum solar
  • energy radiation [1][2] which is corroborated by a 6.5% rapid increase in solar cell efficiency when Sb2Se3 is present [3][4][5]. Interestingly, this high absorption coefficient is 103 times higher than the absorption in silicon [5][6][7] and encompasses a wide portion of the spectrum ranging from 1.0 eV
  • . The onset of edge absorption starts at 1.09 eV (E||c) and 1.1 (E⟂c). In conclusion, the absorption edge splitting (with a high absorption coefficient of ≈104 cm−1) measured at room temperature is 23 meV. In order to investigate the electrical and photoelectric properties of the metal–antimony selenide
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Published 16 Jul 2020

Effect of magnetic field, heat generation and absorption on nanofluid flow over a nonlinear stretching sheet

  • Santoshi Misra and
  • Govardhan Kamatam

Beilstein J. Nanotechnol. 2020, 11, 976–990, doi:10.3762/bjnano.11.82

Graphical Abstract
  • . [4], studied the fluid flow using a semi-infinite flat surface with the heat generation and absorption coefficient. Anderson [5] conducted experiments on fluid flow using the finite difference method which seemed amenable to provide accurate results. The problem involving laminar flow due to
  • slip, the present research incorporates the magnetic field effect and heat generation/absorption coefficient into the velocity, temperature and concentration profiles. Given that the end product is proportional to the heat transfer rate, the most frequent topic of boundary layer flow is the heat
  • expansion coefficient, ρp is the particle density, σ denotes the nanofluid electrical conductivity, B0 denotes the magnetic induction, vw denotes the suction/injection velocity and Q0 (Q) denotes the heat generation (absorption) coefficient. us in Equation 8 represents the slip velocity, given as which is
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Published 02 Jul 2020

Size effects of graphene nanoplatelets on the properties of high-density polyethylene nanocomposites: morphological, thermal, electrical, and mechanical characterization

  • Tuba Evgin,
  • Alpaslan Turgut,
  • Georges Hamaoui,
  • Zdenko Spitalsky,
  • Nicolas Horny,
  • Matej Micusik,
  • Mihai Chirtoc,
  • Mehmet Sarikanat and
  • Maria Omastova

Beilstein J. Nanotechnol. 2020, 11, 167–179, doi:10.3762/bjnano.11.14

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  • used by a Gauss–Newton algorithm to simultaneously adjust the experimental amplitude and phase of the PTR signal analyzed by the lock-in amplifier to extract the thermal diffusivity and optical absorption coefficient of the studied samples. The tensile tests were conducted using an Instron 4301 tensile
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Published 14 Jan 2020

Semitransparent Sb2S3 thin film solar cells by ultrasonic spray pyrolysis for use in solar windows

  • Jako S. Eensalu,
  • Atanas Katerski,
  • Erki Kärber,
  • Lothar Weinhardt,
  • Monika Blum,
  • Clemens Heske,
  • Wanli Yang,
  • Ilona Oja Acik and
  • Malle Krunks

Beilstein J. Nanotechnol. 2019, 10, 2396–2409, doi:10.3762/bjnano.10.230

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  • absorption coefficient, such as Sb2S3 (>105 cm−1 at 450 nm), offer semitransparency, appreciable efficiency, and long-term durability at low cost. Oxide-free throughout the Sb2S3 layer thickness, as confirmed by combined studies of energy dispersive X-ray spectroscopy and synchrotron soft X-ray emission
  • moisture and air as well as sunlight. Sb2S3 has attractive properties (Eg ≈ 1.7 eV, absorption coefficient α ≈ 1.8 × 105 cm−1 at 450 nm, anisotropic structure, inorganic) as a light absorber for conventional and semitransparent photovoltaic use [12][13][14]. Sb2S3 has been incorporated as a solar absorber
  • absorption coefficient curves of Sb2S3 and P3HT. The transmittance of light to the absorber is limited at higher photon energies by the onset of absorption of TiO2 at 3.0 eV and ITO at 3.6 eV. The P3HT layer, however, does not contribute to the generation of photocurrent [14][21]. On the contrary, any
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Published 06 Dec 2019

Design of a nanostructured mucoadhesive system containing curcumin for buccal application: from physicochemical to biological aspects

  • Sabrina Barbosa de Souza Ferreira,
  • Gustavo Braga,
  • Évelin Lemos Oliveira,
  • Jéssica Bassi da Silva,
  • Hélen Cássia Rosseto,
  • Lidiane Vizioli de Castro Hoshino,
  • Mauro Luciano Baesso,
  • Wilker Caetano,
  • Craig Murdoch,
  • Helen Elizabeth Colley and
  • Marcos Luciano Bruschi

Beilstein J. Nanotechnol. 2019, 10, 2304–2328, doi:10.3762/bjnano.10.222

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Published 25 Nov 2019

Nontoxic pyrite iron sulfide nanocrystals as second electron acceptor in PTB7:PC71BM-based organic photovoltaic cells

  • Olivia Amargós-Reyes,
  • José-Luis Maldonado,
  • Omar Martínez-Alvarez,
  • María-Elena Nicho,
  • José Santos-Cruz,
  • Juan Nicasio-Collazo,
  • Irving Caballero-Quintana and
  • Concepción Arenas-Arrocena

Beilstein J. Nanotechnol. 2019, 10, 2238–2250, doi:10.3762/bjnano.10.216

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  • ][8], a high optical absorption coefficient (2 × 105 cm−1) [4], high carrier mobility (2 to 80 cm2/Vs) [4][9] and a large charge carrier lifetime (200 ps) [10]. Therefore, FeS2 nanoparticles (NPs) can be a good alternative for PV applications [11]. Nanostructures of FeS2 have been used as counter
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Published 14 Nov 2019

Nonlinear absorption and scattering of a single plasmonic nanostructure characterized by x-scan technique

  • Tushar C. Jagadale,
  • Dhanya S. Murali and
  • Shi-Wei Chu

Beilstein J. Nanotechnol. 2019, 10, 2182–2191, doi:10.3762/bjnano.10.211

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  • of nonlinear optical constants such as the absorption coefficient (β) or the refractive index (n2). These techniques include the z-scan method (both β and n2) [14], degenerate four-wave mixing (only n2) [15], nearly degenerate three-wave mixing (only n2) [16], optical Kerr gate and ellipse rotation
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Published 06 Nov 2019

Rapid thermal annealing for high-quality ITO thin films deposited by radio-frequency magnetron sputtering

  • Petronela Prepelita,
  • Ionel Stavarache,
  • Doina Craciun,
  • Florin Garoi,
  • Catalin Negrila,
  • Beatrice Gabriela Sbarcea and
  • Valentin Craciun

Beilstein J. Nanotechnol. 2019, 10, 1511–1522, doi:10.3762/bjnano.10.149

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  • treated ITO films is essential in assessing the advantages of the RTA procedure. To obtain information on the bandgap width, absorption coefficient, refractive index, extinction coefficient, dielectric permittivity, position of the impurity levels in the bandgap and characteristics of the optical
  • (Figure 8) on wavelength is similar to that of the absorption coefficient, according to the relationship [42][45][47]: where α is the absorption coefficient, n is the refractive index and c is the speed of light. According to the Drude theory, depending on the dielectric parameters and concentration of
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Published 25 Jul 2019

BiOCl/TiO2/diatomite composites with enhanced visible-light photocatalytic activity for the degradation of rhodamine B

  • Minlin Ao,
  • Kun Liu,
  • Xuekun Tang,
  • Zishun Li,
  • Qian Peng and
  • Jing Huang

Beilstein J. Nanotechnol. 2019, 10, 1412–1422, doi:10.3762/bjnano.10.139

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  • edges of TiO2/diatomite and BTD show a small red shift compared with BiOCl and TiO2. The band gap energy (Eg) of the samples was calculated by the Kubelka–Munk equation [44]: αhν = A(hν − Eg)n/2, and the absorption coefficient, photon energy, a constant and band gap of the sample are expressed by α, hν
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Published 16 Jul 2019

Fe3O4 nanoparticles as a saturable absorber for giant chirped pulse generation

  • Ji-Shu Liu,
  • Xiao-Hui Li,
  • Abdul Qyyum,
  • Yi-Xuan Guo,
  • Tong Chai,
  • Hua Xu and
  • Jie Jiang

Beilstein J. Nanotechnol. 2019, 10, 1065–1072, doi:10.3762/bjnano.10.107

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  • 0.75 m erbium-doped fiber (EDF) with a 110 dB/m peak absorption coefficient at 1530 nm and a dispersion parameter (D) of −36 ps/nm/km. The EDF has an absorption coefficient of 70 dB/m at 980 nm. The fibers in our cavity are all SMF-28 optical fibers (including the pig-tailed fiber) with a dispersion
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Published 20 May 2019

Nanoscale optical and structural characterisation of silk

  • Meguya Ryu,
  • Reo Honda,
  • Adrian Cernescu,
  • Arturas Vailionis,
  • Armandas Balčytis,
  • Jitraporn Vongsvivut,
  • Jing-Liang Li,
  • Denver P. Linklater,
  • Elena P. Ivanova,
  • Vygantas Mizeikis,
  • Mark J. Tobin,
  • Junko Morikawa and
  • Saulius Juodkazis

Beilstein J. Nanotechnol. 2019, 10, 922–929, doi:10.3762/bjnano.10.93

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  • of 0.61λ/NA ≈ 4.1 μm at the 3000 cm−1 band (λ = 3.33 μm). The absorbance or optical density A = −log(T) spectrum is defined by the absorption coefficient α ≡ 4πκ/λ = 2ωκ/c [cm−1] for the transmitted light intensity IT = I0e−αd = I0 × 10−OD; where d is the thickness of sample, the transmittance T = IT
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Published 23 Apr 2019

Synthesis of novel C-doped g-C3N4 nanosheets coupled with CdIn2S4 for enhanced photocatalytic hydrogen evolution

  • Jingshuai Chen,
  • Chang-Jie Mao,
  • Helin Niu and
  • Ji-Ming Song

Beilstein J. Nanotechnol. 2019, 10, 912–921, doi:10.3762/bjnano.10.92

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  • absorption coefficient, h being Planck’s constant, and v being the frequency. The Eg of g-C3N4, CCN and CdIn2S4 are estimated as 2.82 eV, 2.79 eV and 2.26 eV, respectively. Besides, the position of the valence band is determined by the following equation: EVB = X − Ec − 0.5Eg, where Ec is the energy of free
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Published 18 Apr 2019

Towards rare-earth-free white light-emitting diode devices based on the combination of dicyanomethylene and pyranine as organic dyes supported on zinc single-layered hydroxide

  • Jeff L. Nyalosaso,
  • Rachod Boonsin,
  • Pierre Vialat,
  • Damien Boyer,
  • Geneviève Chadeyron,
  • Rachid Mahiou and
  • Fabrice Leroux

Beilstein J. Nanotechnol. 2019, 10, 760–770, doi:10.3762/bjnano.10.75

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  • -sensitivity CCD camera. Photoluminescence excitation (PLE) spectra were obtained by exciting the composite films from 250 to 500 nm with 5 nm increment and measuring their absolute QY. The absolute photoluminescence (PL) QYs were calculated by combining the QY values with the absorption coefficient (also
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Published 25 Mar 2019

Commercial polycarbonate track-etched membranes as substrates for low-cost optical sensors

  • Paula Martínez-Pérez and
  • Jaime García-Rupérez

Beilstein J. Nanotechnol. 2019, 10, 677–683, doi:10.3762/bjnano.10.67

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  • occur during the sensing event. Second, most solutions contain water and it is well known that its absorption coefficient in the NIR region is high [12]. If we place these aqueous solutions on the PCTE membrane in order to detect the presence of any component in it, part of the incident light will be
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Published 07 Mar 2019

Raman study of flash-lamp annealed aqueous Cu2ZnSnS4 nanocrystals

  • Yevhenii Havryliuk,
  • Oleksandr Selyshchev,
  • Mykhailo Valakh,
  • Alexandra Raevskaya,
  • Oleksandr Stroyuk,
  • Constance Schmidt,
  • Volodymyr Dzhagan and
  • Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2019, 10, 222–227, doi:10.3762/bjnano.10.20

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  • sulfide Cu2ZnSnS4 (CZTS); CuS; Cu-Sn-S; kesterite; phonon; pulsed light crystallization; Raman spectroscopy; secondary phase; SnS; Introduction Affordable and non-toxic solar energy materials having a high absorption coefficient and a bandgap in the solar illumination range are an ever-growing research
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Published 17 Jan 2019

Study of silica-based intrinsically emitting nanoparticles produced by an excimer laser

  • Imène Reghioua,
  • Mattia Fanetti,
  • Sylvain Girard,
  • Diego Di Francesca,
  • Simonpietro Agnello,
  • Layla Martin-Samos,
  • Marco Cannas,
  • Matjaz Valant,
  • Melanie Raine,
  • Marc Gaillardin,
  • Nicolas Richard,
  • Philippe Paillet,
  • Aziz Boukenter,
  • Youcef Ouerdane and
  • Antonino Alessi

Beilstein J. Nanotechnol. 2019, 10, 211–221, doi:10.3762/bjnano.10.19

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  • , induces the generation of other defects and increase of the absorption coefficient in the UV range [23][25][28]. The higher efficiency of energy transfer to the network in Ge-doped silica is also suggested by the data of [29] and by the known sensitivity of this kind of silica to UV irradiation even from
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Published 16 Jan 2019
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