scholarly journals Studies on the Optical Properties and Surface Morphology of Nickel Phthalocyanine Thin Films

2007 ◽  
Vol 4 (2) ◽  
pp. 255-264 ◽  
Author(s):  
Benny Joseph ◽  
C. S. Menon
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Band Gap ◽  
Electron Micrographs ◽  
Optical Band Gap ◽  
Scanning Electron Micrographs ◽  
Nickel Phthalocyanine ◽  
Glass Substrates ◽  
Substrate Temperatures ◽  
Scanning Electron

Thin films of Nickel Phthalocyanine (NiPc) are fabricated at a base pressure of 10-5m.bar using Hind-Hivac thermal evaporation plant. The films are deposited on to glass substrates at various temperatures 318, 363, 408 and 458K. The optical absorption spectra of these thin films are measured. Present studies reveal that the optical band gap energies of NiPc thin films are highly dependent on the substrate temperatures. The structure and surface morphology of the films deposited on glass substrates of temperatures 303, 363 and 458K are studied using X-ray diffractograms and Scanning Electron Micrographs (SEM), show that there is a change in the crystallinity and surface morphology due to change in the substrate temperatures. Full width at half maximum (FWHM) intensity of the diffraction peaks is also found reduced with increasing substrate temperatures. Scanning electron micrographs show that these crystals are fiber like at high substrate temperatures. The optical band gap increases with increase in substrate temperature and is then reduced with fiber-like grains at 408K. The band gap increases again at 458K with full of fiber like grains. Trap energy levels are also observed for these films.

scholarly journals Studies on the Optical Properties and Surface Morphology of Cobalt Phthalocyanine Thin Films

2008 ◽  
Vol 5 (1) ◽  
pp. 86-92 ◽  
Author(s):  
Benny Joseph ◽  
C. S. Menon
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Substrate Temperature ◽  
Band Gap ◽  
Optical Band Gap ◽  
Cobalt Phthalocyanine ◽  
Scanning Electron Micrographs ◽  
Glass Substrates ◽  
Substrate Temperatures ◽  
Scanning Electron

Thin films of Cobalt Phthalocyanine (CoPc) are fabricated at a base pressure of 10-5m.bar using Hind-Hivac thermal evaporation plant. The films are deposited on to glass substrates at various temperatures 318, 363, 408 and 458K. The optical absorption spectra of these thin films are measured. The present studies reveal that the optical band gap energies of CoPc thin films are almost same on substrate temperature variation. The structure and surface morphology of the films deposited on glass substrates of temperatures 303, 363 and 458K are studied using X-ray diffractograms and Scanning Electron Micrographs (SEM), which show that there is a change in the crystallinity and surface morphology due to change in the substrate temperatures. Full width at half maximum (FWHM) intensity of the diffraction peaks is also found reduced with increasing substrate temperatures. Scanning electron micrographs show that these crystals are needle like, which are interconnected at high substrate temperatures. The optical band gap energy is almost same on substrate temperature variation. Trap energy levels are also observed for these films.

Absorber Films of Ag2S and AgBiS2 prepared by Chemical Bath Deposition

2002 ◽  
Vol 730 ◽  
Author(s):  
A. Nuñez Rodriguez ◽  
M.T.S. Nair ◽  
P.K. Nair
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Conductivity ◽  
Silver Nitrate ◽  
Band Gap ◽  
Chemical Bath Deposition ◽  
Optical Band Gap ◽  
Sodium Thiosulfate ◽  
Xrd Pattern ◽  
Glass Substrates

AbstractAg2S thin films of 90 nm to 300 nm in thickness were deposited at 70°C on glass substrates immersed in a bath mixture containing silver nitrate, sodium thiosulfate and dimethylthiourea. When the films are heated in nitrogen at temperatures 200°C to 400°C, crystallinity is improved and XRD pattern similar to that of acanthite is observed. These films possess electrical conductivity of 10-3 (ohm cm)-1, are photoconductive and exhibit an optical band gap of 1.36 eV. When Ag2S thin film is deposited over a thin film of Bi2S3, also obtained by chemical bath deposition from bismuth nitrate, triethanolamine and thioacetamide, and heated at 300°C to 400°C in nitrogen, a ternary compound, AgBiS2 is formed. This material has an electrical conductivity of 5x10-5 (ohm cm)-1, is photoconductive and possesses optical band gap 0.95 eV.

scholarly journals The Properties of Zn-Doped AlSb Thin Films Prepared by Pulsed Laser Deposition

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 136
Author(s):  
Ping Tang ◽  
Weimin Wang ◽  
Bing Li ◽  
Lianghuan Feng ◽  
Guanggen Zeng
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Band Gap ◽  
Photovoltaic Effect ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Sem Images ◽  
Glass Substrates ◽  
Substrate Temperatures

Aluminum antimony (AlSb) is a promising photovoltaic material with a band gap of about 1.62 eV. However, AlSb is highly deliquescent and not stable, which has brought great difficulties to the applications. Based on the above situation, there are two purposes for preparing our Zn-doped AlSb (AlSb:Zn) thin films: One is to make P-type AlSb and the other is to find a way to suppress the deliquescence of AlSb. The AlSb:Zn thin films were prepared on glass substrates at different substrate temperatures by using the pulsed laser deposition (PLD) method. The structural, surface morphological, optical, and electrical properties of AlSb:Zn films were investigated. The crystallization of AlSb:Zn thin films was enhanced and the electrical resistivity decreased as the substrate temperature increased. The scanning electron microscopy (SEM) images indicated that the grain sizes became bigger as the substrate temperatures increased. The Raman vibration mode AlSb:Zn films were located at ~107 and ~142 cm−1 and the intensity of Raman peaks was stronger at higher substrate temperatures. In the experiment, a reduced band gap (1.4 eV) of the AlSb:Zn thin film was observed compared to the undoped AlSb films, which were more suitable for thin-film solar cells. Zn doping could reduce the deliquescent speed of AlSb thin films. The fabricated heterojunction device showed the good rectification behavior, which indicated the PN junction formation. The obvious photovoltaic effect has been observed in an FTO/ZnS/AlSb:Zn/Au device.

Absorber Films of Antimony Chalcogenides via Chemical Deposition for Photovoltaic Application

2004 ◽  
Vol 836 ◽  
Author(s):  
M. T. S. Nair ◽  
Y. Rodríguez-Lazcano ◽  
Y. Peña ◽  
S. Messina ◽  
J. Campos ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Chemical Deposition ◽  
Dark Conductivity ◽  
Glass Substrates ◽  
Photovoltaic Application ◽  
Sodium Selenosulfate ◽  
P Type ◽  
Antimony Chalcogenides

ABSTRACTAntimony sulfide thin films (300 nm) have been deposited on glass substrates at 1–10°C from chemical bath. When heated these become crystalline and photoconductive with optical band gap (direct) of 1.7 eV. Thin films formed from chemical baths containing SbCl3 and sodium selenosulfate are of mixed phase Sb2O3/Sb2Se3, which when heated in the presence of Se-vapor converts to single phase Sb2Se3 film with optical band gap of 1.1 eV. Such films possess dark conductivity of 10-8 ohm-1cm-1 and show photosensitivity of two orders. Reaction of Sb2S3-CuS in nitrogen at 400°C produces crystalline, photoconductive p-type CuSbS2 with optical band gap (direct) of 1.5 eV. By controlling the deposition and heating condition, (i)Sb2S3-(p)CuSbS2 layer is formed, which is utilized in a photovoltaic structure, (n)CdS:In-(i)Sb2S3-(p)CuSbS2, with a Voc of 345 mV and Jsc 0.18 mA/cm2 under 1 kW m-2 tungsten halogen illumination. In the case of a structure, CdS:Cl-Sb2S3-Cu2-xSe, Voc of 350 mV and Jsc of 0.5 mA/cm2 are observed.

Modification of Optical Band Gap and Surface Morphology of NiTsPc Thin Films

2012 ◽  
Vol 29 (12) ◽  
pp. 126802 ◽  
Author(s):  
Muhamad Saipul Fakir ◽  
Zubair Ahmad ◽  
Khaulah Sulaiman
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Band Gap ◽  
Optical Band Gap

scholarly journals Effect of gamma irradiation on structural, morphological and optical properties of p-quaterphenyl thin films

2018 ◽  
Vol 14 (2) ◽  
pp. 5624-5637
Author(s):  
A.A. Attia ◽  
M.M. Saadeldin ◽  
K. Sawaby
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Surface Morphology ◽  
Absorption Coefficient ◽  
Gamma Irradiation ◽  
Band Gap ◽  
Optical Band Gap ◽  
Thermal Evaporation Method ◽  
Single Oscillator Model

Para-quaterphenyl thin films were deposited onto glass and quartz substrates by thermal evaporation method. p-quaterphenyl thin films wereexposed to gamma radiation of Cobat-60 radioactive source at room temperature with a dose of 50 kGy to study the effect of ?-irradiation onthe structure and the surface morphology as well as the optical properties of the prepared films. The crystalline structure and the surface morphology of the as-deposited and ?-irradiated films were examined using the X-ray diffraction and the field emission scanning electron microscope. The optical constants (n & k) of the as-deposited and ?-irradiated films were obtained using the transmittance and reflectance measurements, in the wavelength range starting from 250 up to 2500 nm. The analysis of the absorption coefficient data revealed an allowed direct transition with optical band gap of 2.2 eV for the as-deposited films, which decreased to 2.06 eV after exposing film to gamma irradiation. It was observed that the Urbach energy values change inversely with the values of the optical band gap. The dispersion of the refractive index was interpreted using the single oscillator model. The nonlinear absorption coefficient spectra for the as-deposited and ?-irradiated p-quaterphenyl thin films were obtained using the linear refractive index.

scholarly journals Surface morphology of the fish parasite Chonopeltis victori Avenant- Oldewage, 1991 and aspects of the histomorphology

Koedoe ◽  
1996 ◽  
Vol 39 (1) ◽  
Author(s):  
Wilmien J. Luus-Powell ◽  
Annemarie Avenant-Oldewage
Keyword(s):  
Sexual Dimorphism ◽  
Surface Morphology ◽  
Electron Micrographs ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
Scanning Electron Micrographs ◽  
Fish Parasite ◽  
Large Numbers ◽  
Different Shapes ◽  
Scanning Electron

The ultrastructure and aspects of the histomorphology of Chonopeltis victori, parasitic on Labeo rosae, L. congoro, L. ruddi, L. cylindricus and Barbus marequensis, are described from scanning electron micrographs and transverse sections. Chonopeltis victori is characterised by sharply pointed tips of the abdomen which are directed outward. Sexual dimorphism is particularly evident from the structure of the natatory lobes on the fourth swimming legs and the accessory copulatory structures on the second, third and fourth swimming legs of males. The most striking feature on leg four of the male is the peg. The elevated peg appears tubular, but the sides are not fused. On the inner collar elliptical projections, each with a central, circular pore, are present. On the elongated outer collar small indentions occur peripherally. The dorsal surface of the peg is subterminally covered by elongated scales. The ventral surface of the thorax and swimming legs are covered with different shapes of posteriorly directed scales. Interspersed amongst these scales, as well as on the dorsal surface, eight types of setae are present in large numbers. The possible function of the peg and other structures are described.

Properties of TiO2 Thin Film Prepared by Sol-Gel Dip Coating

2015 ◽  
Vol 723 ◽  
pp. 528-531
Author(s):  
Jun Wang ◽  
Ling Yun Bai
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Dip Coating ◽  
Gel Method ◽  
Glass Substrates

TiO2 thin films were prepared on glass substrates by sol-gel method. The effect of withdraw speed on the thickness and optical properties of TiO2 thin films was investigated. The films were transparent in the visible wavelength. The thickness of the TiO2 films was increased from 90 nm for the withdraw speed of 1000 μm/s to 160 nm for the withdraw speed of 2000 μm/s. While, The refractive index of the TiO2 thin film decreased from 2.38 to 2.07. It may be due to the porosity of the film was increased. The optical band-gap of the films was around 3.45 eV.

LOWER TEMPERATURE FORMATION OF ALUMINA THIN FILMS THROUGH SOL–GEL ROUTE

2008 ◽  
Vol 15 (05) ◽  
pp. 681-688 ◽  
Author(s):  
S. RIAZ ◽  
S. SHAMAILA ◽  
B. KHAN ◽  
S. NASEEM
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Structural Changes ◽  
Sol Gel ◽  
Stable Form ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Lower Temperature ◽  
Xrd Patterns ◽  
Scanning Electron

Bayerite sol is spun onto single crystal Si substrate, after synthesis and optimization, to obtain films of thickness ~ 0.2 μm. The deposited films are room temperature dried and then heated up to a temperature of 350°C in order to obtain Al 2 O 3. Surface and structural changes, during heating, are observed with optical microscopy. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) are used for post-treatment analyses/characterization. The as-deposited and heated samples' surfaces are smooth as seen with optical and scanning electron microscope in case of optimized conditions. XRD patterns show the change from amorphous to crystalline behavior of these films when heated under various conditions. The most stable form of aluminum oxide, i.e. α- Al 2 O 3, is obtained when samples are heated up to a temperature of as low as 350°C. The thin films are also deposited onto sodalime glass substrates in order to confirm Al 2 O 3 formation through band gap probing. Photoconduction is used to find the energy band gap, which comes out to be 4.7 eV; lower value is correlated to the defect induced states in the band gap.

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