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.

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.

Effect of Substrate Temperature on the Electrochromic Properties of Cobalt Hydroxide Thin Films Prepared by Reactive Sputtering

2011 ◽  
Vol 1328 ◽  
Author(s):  
KyoungMoo Lee ◽  
Yoshio Abe ◽  
Midori Kawamura ◽  
Hidenobu Itoh
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Indium Tin Oxide ◽  
Large Change ◽  
Amorphous Structure ◽  
Cobalt Hydroxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Substrate Temperatures

ABSTRACTCobalt hydroxide thin films with a thickness of 100 nm were deposited onto glass, Si and indium tin oxide (ITO)-coated glass substrates by reactively sputtering a Co target in H2O gas. The substrate temperature was varied from -20 to +200°C. The EC performance of the films was investigated in 0.1 M KOH aqueous solution. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy of the samples indicated that Co3O4 films were formed at substrate temperatures above 100°C, and amorphous CoOOH films were deposited in the range from 10 to -20°C. A large change in transmittance of approximately 26% and high EC coloration efficiency of 47 cm2/C were obtained at a wavelength of 600 nm for the CoOOH thin film deposited at -20°C. The good EC performance of the CoOOH films is attributed to the low film density and amorphous structure.

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.

Electrical Properties of Pulsed Laser Deposited ZnO Thin Films

2009 ◽  
Vol 67 ◽  
pp. 121-125
Author(s):  
Chattopadhyay Sourav ◽  
Kumar Nath Tapan
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Substrate Temperature ◽  
Hall Mobility ◽  
Pulsed Laser ◽  
Deposition Process ◽  
Zno Thin Films ◽  
Zno Films ◽  
Visible Absorption ◽  
Substrate Temperatures

Epitaxial Single-crystal ZnO thin films have been grown on c-plane (0001) sapphire by Pulsed Laser Deposition process at different substrate temperatures (300 – 800 °C) with 10-1 mbar oxygen pressure. The thicknesses of the films have been varied by varying number of pulses with a repetition rate of 10 pulse/sec. It is found that the sheet resistivity of ZnO thin films grown on c-plane sapphires are in the order of 10-2 Ω-cm and it increases with increasing substrate temperatures and film thickness. The carrier concentrations and Hall mobility are found to be in the order of 1017 cm-3 and ~195 cm2/V-s, respectively. The Hall mobility slightly decreases with increase of substrate temperature and thickness of the films. It is also found that the ZnO films are structurally uniform and well oriented with perfect wurtzite structure with c/a ratio 5.1. We have also deposited non-epitaxial ZnO films on (100) p-Silicon substrates at the same conditions. From HR FE-SEM micrographs, surface morphology of ZnO films grown at lower substrate temperature are found to be uniform compared to the films grown at higher temperatures showing non-uniformity and misoriented wurtzite structures. However, the surface morphology of ZnO flims grown epitaxially on (0001) sapphire are found to be more uniform and it does not change much with growth temperature. The resistivity of the films grown on p-Silicon at higher temperatures is in the order of 103 Ω-cm whereas films grown at lower substrate temperatures show comparatively lower resistivities (~ 102 Ω-cm). From the recorded UV-Visible absorption spectrum the band gap of the film has been estimated to be 3.38 eV.

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.

SURFACE MORPHOLOGY AND PHOTOLUMINESCENCE CHARACTERISTICS OF Sm-DOPED YVO4 THIN FILMS

2007 ◽  
Vol 14 (05) ◽  
pp. 873-878 ◽  
Author(s):  
HYUN KYOUNG YANG ◽  
JONG WON CHUNG ◽  
BYUNG KEE MOON ◽  
BYUNG CHUN CHOI ◽  
JUNG HYUN JUNG ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Substrate Temperature ◽  
Photoluminescence Intensity ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Zircon Structure ◽  
Substrate Temperatures

Surface morphology and crystallinity of YVO 4: Sm 3+ thin films have an influence on the photoluminescence characteristics. The YVO 4: Sm 3+ films have been deposited on Al 2 O 3 (0001) substrates using pulsed laser deposition method. The films were grown at the various substrate temperatures changing from 500 to 700°C. The crystallinity and surface morphology of the films were investigated using X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. The results of XRD showed that YVO 4: Sm 3+ films had a zircon structure and AFM study revealed that the films consisted of homogeneous grains ranging from 100 to 400 nm depending on the deposition conditions. The photoluminescence spectra were measured at room temperature and the emitted radiation was dominated by the red emission peak at 620 nm radiated from the transition of 5 D 0-7 F 2. The crystallinity, surface morphology, and photoluminescence spectra of thin-film phosphors were highly dependent on the substrate temperature. The surface roughness and photoluminescence intensity of the films showed similar behavior as a function of substrate temperature.

Sign in / Sign up

Export Citation Format

Share Document