THICKNESS DEPENDENCE OF THIRD-HARMONIC GENERATION FROM SELF-ASSEMBLED REGIOREGULAR POLY(3-HEXYLTHIOPHENE) THIN FILMS ON QUARTZ GLASSES WITH DIFFERENT SURFACES

2008 ◽  
Vol 17 (04) ◽  
pp. 451-463 ◽  
Author(s):  
XIN WANG ◽  
JIASHENG RU ◽  
SHIZUYASU OCHIAI ◽  
YUU YAMADA ◽  
YOSHIYUKI UCHIDA ◽  
...  
Keyword(s):  
Thin Films ◽  
Visible Absorption ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Cast Films ◽  
Regioregular Poly ◽  
Out Of Plane ◽  
Self Assembled ◽  
Quartz Glasses

Regioregular poly(3-hexylthiophene) [RR-P3HT] thin films were prepared on fused quartz glasses by spin-coating and drop-casting from the chloroform solutions. Film structures and morphologies were characterized by UV-visible absorption spectra, out-of-plane X-ray diffraction (XRD) and atomic force microscopy (AFM). Drop-cast films showed increased χ(3) of about three times higher than that of the spin-coated ones when the film thicknesses were both around 140 nm, and the magnitude of the increase was different for different thickness. The magnitudes of χ(3) for drop-cast RR-P3HT films were calculated in the range of 10-11 esu, and the phases of χ(3) lay in the range from 230 to 300° which were consistent with the contributions from two-photon absorptions (TPA). Hexamethyldisilazane (HMDS) treatment of the glass substrates could increase the χ(3) of drop-cast films further from about ten percent to several times higher. This also depended on the film thickness. These results revealed the deposition method and surface modification effects on the self-assembled RR-P3HT film structures, and the importance of higher-ordering and increased crystallinity for the enhancement of the χ(3) of the polymeric films for their applications in NLO devices.

WO3:Mo and WO3:Ti Thin Films Deposited by Spray Pyrolysis: The Influence of Metallic Concentration on Physical Properties: An Electron Microscopy and Atomic Force Study

2019 ◽  
Vol 286 ◽  
pp. 49-63
Author(s):  
Dwight Acosta ◽  
Francisco Hernández ◽  
Alejandra López-Suárez ◽  
Carlos Magaña
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Ultra Violet ◽  
Surface Characteristics ◽  
Structural Defects ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Transmission Electron ◽  
Resolution Electron

WO3:Mo and WO3:Ti thin films have been deposited on FTO/Glass substrates by the pulsed chemical spray technique at a substrate temperature of Ts= 450°C. The influence of Mo and Ti doping on the structural, electrical, and optical behavior of WO3thin films, has been studied by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), Ultra Violet and Visible Spectrometry (UV-VIS), and Surface Conductivity Methods (Four Points). Doped WO3films presents similar polycrystalline structures but with noticeable modifications in surface configurations at micrometric and nanometric levels, as the Mo and Ti concentration is systematically increased in the starting sprayed solution. From processed High-Resolution Electron Micrographs (HREM), a low density of structural defects was found on pure and doped WO3grains. This lead to conclude that variations in films surface characteristics are mainly related with metallic doping concentrations which in turn, have noticeable influence in electrical and optical behaviors reported in this work.

scholarly journals Investigating the Nanocomposite Thin Films of Hematite α-Fe2O3 and Nafion for Cholesterol Biosensing Applications

2020 ◽  
Vol 2 ◽  
Author(s):  
Indra Sulania ◽  
R. Blessy Pricilla ◽  
G. B. V. S. Lakshmi
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Differential Pulse ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Enzyme Substrate ◽  
Atomic Force ◽  
Nanocomposite Thin Films ◽  
Multi Phase ◽  
Cholesterol Biosensor

Nanocomposite materials are multi-phase materials, usually solids, which have two or more component materials having different chemical and physical properties. When blended together, a newer material is formed with distinctive properties which make them an eligible candidate for many important applications. In the present study, thin films of nafion (polymer) and hematite or α-Fe2O3 (nanoparticles) nanocomposite is fabricated on indium tin oxide (ITO) coated glass substrates, due to its enhanced ionic conductivity, for cholesterol biosensor applications. Scanning electron microscopy and Atomic force microscopy revealed the formation of nanorod structured α-Fe2O3 in the films. The cyclic voltammetry (CV) studies of nafion-α-Fe2O3/ITO revealed the redox properties of the nanocomposites. The sensing studies were performed on nafion-α-Fe2O3/CHOx/ITO bioelectrode using differential pulse voltammetry (DPV) at various concentrations of cholesterol. The enzyme immobilization leaded to the selective detection of cholesterol with a sensitivity of 64.93 × 10−2 μA (mg/dl)−1 cm−2. The enzyme substrate interaction (Michaelis–Menten) constant Km, was obtained to be 19 mg/dl.

Synthesis and Characterization of Nb-Doped TiO2 Thin Films Prepared by RF Magnetron Sputtering

2015 ◽  
Vol 1117 ◽  
pp. 139-142 ◽  
Author(s):  
Marius Dobromir ◽  
Radu Paul Apetrei ◽  
A.V. Rogachev ◽  
Dmitry L. Kovalenko ◽  
Dumitru Luca
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Rf Magnetron Sputtering ◽  
X Ray ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Diffraction Patterns

Amorphous Nb-doped TiO2 thin films were deposited on (100) Si and glass substrates at room temperature by RF magnetron sputtering and a mosaic-type Nb2O5-TiO2 sputtering target. To adjust the amount of the niobium dopant in the film samples, appropriate numbers of Nb2O5 pellets were placed on the circular area of the magnetron target with intensive sputtering. By adjusting the discharge conditions and the number of niobium oxide pellets, films with dopant content varying between 0 and 16.2 at.% were prepared, as demonstrated by X-ray photoelectron spectroscopy data. The X-ray diffraction patterns of the as-deposited samples showed the lack of crystalline ordering in the samples. Surfaces roughness and energy band gap values increase with dopant concentration, as showed by atomic force microscopy and UV-Vis spectroscopy measurements.

Structural and Optical Properties of PbI2 Thin Films to Fabricate Perovskite Solar Cells

2020 ◽  
Vol 398 ◽  
pp. 140-146
Author(s):  
Kawther A. Khalaph ◽  
Zainab J. Shanan ◽  
Aqel Mashot Jafar ◽  
Falah Mustafa Al-Attar
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Energy Gap ◽  
Perovskite Solar Cells ◽  
Lead Iodide ◽  
Structural And Optical Properties ◽  
Solar Cell Application ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force

Recently, lead iodide is the most materials employment in the perovskite solar cell application. This paper has studied the character of preparation, structural and optical properties of pbI2 materials. Structural properties are included investigation of the measurements X-Ray Diffraction (XRD), Scan Electron Microscopy (SEM), Fourier Transform InfraRed spectroscopy (FTIR) and Atomic Force Microscopy (AFM) tests to the PbI2 thin films samples. Optical properties are included the investigation UV-Vis test of the thin film samples deposited on glass substrates and investigated the Absorption, Transmittance and evaluated energy gap (Eg = 2.3 eV).

Two conductive mechanisms in LaMnO3 thin film: Adiabatic and nonadiabatic small polaronic hopping

2021 ◽  
pp. 2150310
Author(s):  
Weiyuan Wang ◽  
Jiyu Fan ◽  
Huan Zheng ◽  
Jing Wang ◽  
Hao Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
Theoretical Models ◽  
Magnetic Phase Transitions ◽  
Epitaxial Thin Films ◽  
X Ray Diffraction ◽  
Epitaxial Relationship ◽  
Reciprocal Space Mapping ◽  
Force Microscopy ◽  
Atomic Force ◽  
Out Of Plane

We have presented the structural, surface morphology, magnetic and resistivity data for perovskite LaMnO3 epitaxial thin films which are fabricated on well-oriented (001) LaAlO3 substrates by pulsed laser deposition technique. X-ray diffraction [Formula: see text]–[Formula: see text] linear scans and reciprocal space mapping measurement confirm that the out-of-plane and in-plane epitaxial relationship are LMO(001)/LAO(001) and LMO(110)/LAO(110), respectively. Surface roughness determined by atomic force microscopy was no more than 0.3 nm. In the whole studied temperature range, all films only show a paramagnetic behavior instead of any magnetic phase transitions. Correspondingly, the electron transport behaviors always exhibit an insulting state as the temperature changes from high to low. However, we find that none of theoretical models can individually be used to understand their conductive mechanisms. Further studies indicated that charge carries of high and low temperature region obey adiabatic and nonadiabatic small polaronic hopping mechanisms, respectively. This finding offers new ways of exploiting the abnormal ferromagnetism in LaMnO3 multilayer thin films.

Study Morphology Transitions in Self-Assembled Triblock Copolymer Thin Films with Nanostructures by AFM

2006 ◽  
Vol 532-533 ◽  
pp. 165-168
Author(s):  
Yong Zhi Cao ◽  
Shen Dong ◽  
Ying Chun Liang ◽  
Tao Sun
Keyword(s):  
Thin Films ◽  
Block Copolymer ◽  
Triblock Copolymer ◽  
Low Cost ◽  
Orientational Order ◽  
Solvent Annealing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ordered Nanostructures ◽  
Self Assembled

As a “bottom-up” approach to nanostructures for nanofabrication, self-assembled block copolymer thin films have received much attention not only thanks to the scale of the microdomains but also due to the convenient shape tunability. In order to realize applications of self-assembled block copolymer thin films in nanotechnologies, control over microdomain spatial and orientational order is paramount. In this paper, using atomic force microscopy (AFM), we studied systemically nanostructure transitions induced by post-solvent annealing in self-assembled block copolymer thin films. Furthermore, a variety of thin films with well-ordered nanostructures, which can be employed as templates for nanotechnologies, have been realized simply and at low cost.

Dielectric and Electromechanical Behaviour of Relaxor [(1−x)Pb(Mg1/3Nb2/3)O3 -xPbTiO3] Thin Films

2001 ◽  
Vol 688 ◽  
Author(s):  
N.J. Donnelly ◽  
G. Catalan ◽  
C. Morros ◽  
R.M. Bowman ◽  
J.M. Gregg
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Plane Strain ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Bulk Ceramic ◽  
Atomic Force ◽  
Out Of Plane ◽  
Order Of Magnitude

AbstractThin film capacitor structures of Au / (1−x)Pb(Mg1/3Nb2/3)O3 - xPbTiO3 /(La1/2Sr1/2)CoO3 were fabricated by pulsed laser deposition on single crystal {001} MgO substrates. Films were found to be perovskite dominated and highly {001} oriented. Dielectrically, films displayed relaxorlike features, though maximum permittivity was low compared to single crystal or bulk ceramic (∼1400 at peak @1kHz, for x=0.07, 0.1 & 0.2). A field induced piezoelectric coefficient d33 was measured by piezoresponse atomic force microscopy for specific compositions x =0, × =0.07, and x =0.1 and found to be disappointingly low - indicating poor electric field induced strain. Despite this macroscopic electrostrictive coefficients Q33 were found to be (3.6 ± 0.6) ×10−2C−2m4, (2.6 ± 0.2) ×10−2C−2m4, and (0.9 ± 0.3) ×10−2C−2m4 respectively. Crystallographic electrostrictive coefficients were determined by in-situ x-ray diffraction and found to be (4.9 ± 0.2) ×10−2C−2m4 for PMN-(0.07)PT and (1.9 ± 0.1) ×10−2C−2m4 for PMN-(0.1)PT. Considering that all these Q33 values are of the same order of magnitude as found in single crystal experiments (2.5 – 3.8 ×10−2C−2m4), it is suggested that low out-of-plane strain is entirely a result of reduced polarisability rather than reduced electrostrictive coefficients in thin films relative to bulk ceramic or single crystal. An estimate was also made of the Q13 electrostrictive coefficient for PMN and PMN-(0.07)PT by measuring permittivity as a function of applied in-plane strain. The values obtained were -1.31 ×10−2C−2m4 and -0.46 ×10−2C−2m4 respectively.

Chemically Deposited Silver Antimony Selenide Thin Films for Photovoltaic Applications

2009 ◽  
Vol 1165 ◽  
Author(s):  
Jorge G. Garza ◽  
Sadasivan Shaji ◽  
Ana Maria Arato Tovar ◽  
Eduardo Perez Tijerina ◽  
Alan Castillo Roderiguez ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Close Contact ◽  
Optical Transmittance ◽  
Halogen Lamp ◽  
X Ray ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Antimony Selenide

AbstractSilver antimony selenide (AgSbSe2) thin films were prepared by heating sequentially deposited antimony sulphide (Sb2S3), silver selenide (Ag2Se) and Ag thin films in close contact with a selenium thin film. Sb2S3 thin film was prepared from chemical bath containing SbCl3 and Na2S2O3, Ag2Se from the bath containing AgNO3 and Na2SeSO3 and Se thin films from an acidified solution of Na2SeSO3, at room temperature on cleaned glass substrates. Ag thin film was deposited by vacuum thermal evaporation. The annealing temperature was varied from 300-390°C in vacuum (∼10−3 Torr) for 1 h. X-ray diffraction analysis showed the films formed at 350 °C was polycrystalline AgSb(S,Se)2 or AgSbSe2 depending on selenium thin film thickness. Morphology of these films was analyzed using Atomic Force Microscopy and Scanning Electron Microscopy. The elemental analysis was done using Energy Dispersive X-ray technique. Optical characterization of the thin films was done by optical transmittance spectra. The electrical characterizations were done using Hall effect and photocurrent measurements. A photovoltaic structure: Glass/ITO/CdS/AgSbSe2/Ag was formed, in which CdS was deposited by chemical bath deposition. J-V characteristics of this PV structure showed Voc=370 mV and Jsc=0.5 mA/cm2 under illumination using a tungsten halogen lamp.

ON THE ELECTRONIC TRANSPORT MECHANISM IN MAGNETRON-SPUTTERED POLYCRYSTALLINE ZnO THIN FILMS

2010 ◽  
Vol 24 (31) ◽  
pp. 6079-6090 ◽  
Author(s):  
I. I. RUSU ◽  
M. SMIRNOV ◽  
G. G. RUSU ◽  
A. P. RAMBU ◽  
G. I. RUSU
Keyword(s):  
Thin Films ◽  
Electronic Transport ◽  
Hexagonal Structure ◽  
Zno Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Crystallite Boundary

Zinc oxide ( ZnO ) thin films were deposited onto glass substrates by d.c. magnetron sputtering. The structural analysis, by X-ray diffraction and atomic force microscopy, indicate that the studied films are polycrystalline and have a wurtzite (hexagonal) structure. The film crystallites are preferentially oriented with (002) planes parallel to the substrates. The mechanism of electronic transport is explained in terms of Seto's model elaborated for polycrystalline semiconducting films (crystallite boundary trapping theory). Some parameters of used model (impurity concentration, density and energy of the trapping states, etc.) have been calculated. The optical bandgap (Eg0 = 3.28–3.37 eV ) was determined from absorption spectra.

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