Morphological Studies on Spray Deposited Lanthanum Sulphide (La2S3) Thin Films

2016 ◽  
Vol 705 ◽  
pp. 283-288
Author(s):  
G.D. Bagde ◽  
C.T. Londhe ◽  
A.G. Bagde
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Measurement Techniques ◽  
Film Properties ◽  
Direct Band Gap ◽  
Morphological Studies ◽  
Fibrous Network ◽  
Direct Band ◽  
Xrd Studies ◽  
P Type

The spray pyrolysis was employed to prepare Lanthanum Sulphide (La2S3) thin films on silicon non conducting glass substrate using lanthanum chloride and thioacetamide from aqueous medium. The effect of preparative parameters on film properties was studied. Further thin films characterization was carried out by electrical resistivity, thermoemf, optical, XRD and SEM measurement techniques. The electrical resistivity was the order of 104 – 105 Ω cm and it shows semiconducting behavior. The Thermoemf studies reveal that Lanthanum Sulphide material is P-type. The direct band gap of Lanthanum Sulphide (La2S3) thin films was estimated to be 2.5 eV. The XRD studies indicate that Lanthanum Sulphide (La2S3) thin films are polycrystalline. A morphological study shows that the Lanthanum Sulphide (La2S3) thin films have fibrous network.

Spray Chemical Vapor Deposition of CuInS2 Thin Films for Application in Solar Cell Devices

1997 ◽  
Vol 495 ◽  
Author(s):  
Jennifer A. Hollingsworth ◽  
William E. Buhro ◽  
Aloysius F. Hepp ◽  
Philip P. Jenkins ◽  
Mark A. Stan
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Band Gap ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Fused Silica ◽  
Direct Band Gap ◽  
Cuins2 Thin Films ◽  
Potential Applications ◽  
Direct Band

ABSTRACTChalcopyrite CuInS2 is a direct band gap semiconductor (1.5 eV) that has potential applications in photovoltaic thin film and photoelectrochemical devices. We have successfully employed spray chemical vapor deposition using the previously known, single-source, metalorganic precursor, (Ph3P)2CuIn(SEt)4, to deposit CuInS2 thin films. Stoichiometric, polycrystalline films were deposited onto fused silica over a range of temperatures (300–400 °C). Morphology was observed to vary with temperature: spheroidal features were obtained at lower temperatures and angular features at 400 °C. At even higher temperatures (500 °C), a Cu-deficient phase, CuIn5S8, was obtained as a single phase. The CuInS2 films were determined to have a direct band gap of ca. 1.4 eV.

Thermoelectric Module of P-Type Ca-Co-O/N-Type ZnO Thin Films

2012 ◽  
Vol 622-623 ◽  
pp. 726-733 ◽  
Author(s):  
Weerasak Somkhunthot ◽  
Nuwat Pimpabute ◽  
Tosawat Seetawan
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Power Factor ◽  
Electrical Power ◽  
Thermoelectric Module ◽  
Preliminary Test ◽  
Internal Resistance ◽  
Open Circuit ◽  
P Type

Thin films thermoelectric module fabricated by pulsed-dc magnetron sputtering system using Ca3Co4O9(p-type) and ZnO (n-type) targets of 60 mm diameter and 2.5 mm thickness, which were made from powder precursor, and obtained by solid state reaction. Thin films of p-Ca-Co-O (Seebeck coefficient = 143.85 µV/K, electrical resistivity = 4.80 mΩm, power factor = 4.31 µW/m K2) and n-ZnO (Seebeck coefficient =229.24 µV/K, electrical resistivity = 5.93 mΩm, power factor = 8.86 µW/m K2) were used to make a thermoelectric module, which consist of four pairs of legs connected by copper electrodes (0.5 mm thickness, 3.0 mm width, and 3.0-8.0 mm length). Each leg is 3.0 mm width, 20.0 mm length, and 0.44 µm thickness on a glass substrate of 1.0 mm thickness in dimension 25.0x50.0 mm2. For preliminary test, a module was used to thermoelectric power generation. It was found that the open circuit voltage increased with increasing temperature difference from 3 mV at 5 K up to 20 mV at 78 K. The internal resistance of a module reached a value of 14.52 MΩ. This test indicated that a module can be generated the electrical power. Therefore, it can be used as an important platform for further thin films thermoelectric module research.

scholarly journals Nickel doping effect on the structural and optical properties of indium sulfide thin films by SILAR

2018 ◽  
Vol 16 (1) ◽  
pp. 757-762 ◽  
Author(s):  
Fatma Göde ◽  
Serdar Ünlü
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Doping Concentration ◽  
Indium Sulfide ◽  
Ni Doping ◽  
X Ray ◽  
Direct Band Gap ◽  
Direct Band ◽  
Ni Dopant

AbstractUndoped and nickel doped indium sulfide (In2S3:Ni) thin films have been deposited on indium tin oxide (ITO) coated glass substrates by successive ionic layer adsorption and reaction (SILAR) method. The doping concentration of Ni has been adjusted as 4%, 5% and 6% (in molar ratio of nickel ions to indium ions). The effects of Ni doping on the structural, morphological, compositional and optical properties of the In2S3 thin films are investigated. The x-ray diffraction patterns show that deposited film has cubic structure with amorphous nature of In2S3 and its crystallinity deteriorates with increasing doping concentration. The SEM measurements show that the surface morphology of the films is affected from the Ni incorporation. The direct band gap of the films decreases from 2.33 eV to 1.61 eV with increasing Ni dopant. Energy dispersive x-ray spectroscopy (EDS) has been used to evaluate the chemical composition and shown that S/(Ni+In) ratio in films decreases from 1.18 to 0.40 with Ni content. Optical properties of the films have been performed by a UV-Vis spectrophotometer. The direct band gap of the films decreases from 2.33 eV to 1.61 eV with increasing Ni dopant. Moreover, optical parameters of the films such as refractive index (𝑛), extinction coefficient (k), real (ε1) and imaginary (ε2) parts of dielectric constant have been determined by using absorbance and transmittance spectra. The investigations showed that the Ni doping has a significant effect on the physical properties of SILAR produced In2S3 thin films.

Electronic State and Piezoresistivity Analysis of Zinc Oxide Nanowires for Force Sensing Devices

2015 ◽  
Vol 644 ◽  
pp. 16-21 ◽  
Author(s):  
Koichi Nakamura
Keyword(s):  
Band Gap ◽  
Compressive Strain ◽  
Force Sensing ◽  
Wall Structure ◽  
Direct Band Gap ◽  
Direct Band ◽  
The Difference ◽  
Piezoresistance Coefficient ◽  
Indirect Band Gap ◽  
P Type

The piezoresistivity for force sensing in wurtzite-ZnO nanowires with [0001] orientation has been simulated on the basis of the first-principles calculations of model structures. According to the difference in wall structure, our devised nanowire models can be divided into three groups by their conductivities; no band-gap conducting models, direct band-gap semiconducting models, and indirect band-gap semiconducting models. The strain responses to carrier conductivity of n-or p-doped semiconducting wurtzite-ZnO[0001] nanowire models were calculated using band carrier densities and their corresponding effective masses derived from the one-dimensional band diagram by our original procedure for a small amount of carrier occupation. The conductivities of p-type direct band-gap models change drastically due to longitudinal uniaxial strain in the simulation: the longitudinal piezoresistance coefficient is 120 × 10–11 Pa–1 for p-type (ZnO)24 nanowire model with 1% compressive strain at room temperature.

SOLUTION PROCESSING OF CADMIUM SULFIDE BUFFER LAYER AND ALUMINUM-DOPED ZINC OXIDE WINDOW LAYER FOR THIN FILMS SOLAR CELLS

2014 ◽  
Vol 21 (04) ◽  
pp. 1450059 ◽  
Author(s):  
MAHBOOB ALAM ◽  
MOHAMMAD ISLAM ◽  
AMINE ACHOUR ◽  
ANSAR HAYAT ◽  
BILAL AHSAN ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Electrical Resistivity ◽  
Solar Cells ◽  
Annealing Temperature ◽  
Window Layer ◽  
Zno Thin Films ◽  
Bath Composition ◽  
Film Properties ◽  
Aluminum Doped Zinc Oxide

Cadmium sulfide ( CdS ) and aluminum-doped zinc oxide ( Al : ZnO ) thin films are used as buffer layer and front window layer, respectively, in thin film solar cells. CdS and Al : ZnO thin films were produced using chemical bath deposition (CBD) and sol–gel technique, respectively. For CBD CdS , the effect of bath composition and temperature, dipping time and annealing temperature on film properties was investigated. The CdS films are found to be polycrystalline with metastable cubic crystal structure, dense, crack-free surface morphology and the crystallite size of either few nanometers or 12–17 nm depending on bath composition. In case of CdS films produced with 1:2 ratio of Cd and S precursors, spectrophotometer studies indicate quantum confinement effect, owing to extremely small crystallite size, with an increase in Eg value from 2.42 eV (for bulk CdS ) to ~ 3.76 eV along with a shift in the absorption edge toward ~ 330 nm wavelength. The optimum annealing temperature is 400°C beyond which film properties deteriorate through S evaporation and CdO formation. On the other hand, Al : ZnO films prepared via spin coating of precursor sols containing 0.90–1.10 at.% Al show that, with an increase in Al concentration, the average grain size increases from 28 nm to 131 nm with an associated decrease in root-mean-square roughness. The minimum value of electrical resistivity, measured for the films prepared using 0.95 at.% Al in the precursor sol, is ~ 2.7 × 10-4 Ω ⋅ cm. The electrical resistivity value rises upon further increase in Al doping level due to introduction of lattice defects and Al segregation to the grain boundary area, thus limiting electron transport through it.

Preparation of SnS Thin Films by Close-Spaced Sublimation at Different Source Temperatures

2012 ◽  
Vol 590 ◽  
pp. 148-152 ◽  
Author(s):  
Xiao Ping Zhan ◽  
Cheng Wu Shi ◽  
Xin Jie Shen ◽  
Min Yao ◽  
Yan Ru Zhang
Keyword(s):  
Thin Films ◽  
Band Gaps ◽  
X Ray Diffraction ◽  
X Ray ◽  
Direct Band Gap ◽  
Source Temperature ◽  
Nir Absorption ◽  
Structure Surface ◽  
Direct Band ◽  
Sns Thin Films

In this paper, thin films of tin monosulfide (SnS) were successfully prepared by close-spaced sublimation (CSS) on the source temperature of 650 °C and 720 °C using SnS powder as a source. The influence of the source temperature on the chemical composition, crystal structure, surface morphology, and direct band gap of SnS thin films was systemically investigated by energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis-NIR absorption spectra, respectively. The results showed that the SnS grain size increased from 3 μm to 20 μm by increase of the source temperature from 650 °C to 720 °C. The direct band gaps of SnS thin films prepared at different source temperatures 650 °C and 720 °C were 1.21 and 1.15 eV, respectively.

Lead-free perovskite ferroelectric thin films with narrow direct band gap suitable for solar cell applications

2017 ◽  
Vol 95 ◽  
pp. 56-60 ◽  
Author(s):  
Qingfeng Zhang ◽  
Fang Xu ◽  
Maji Xu ◽  
Lei Li ◽  
Yinmei Lu ◽  
...  
Keyword(s):  
Thin Films ◽  
Solar Cell ◽  
Band Gap ◽  
Ferroelectric Thin Films ◽  
Lead Free ◽  
Direct Band Gap ◽  
Direct Band

MORPHOLOGY AND ELECTRICAL RESISTIVITY OF AuCu NANOFILM ALLOYS

2008 ◽  
Vol 15 (06) ◽  
pp. 881-888 ◽  
Author(s):  
R. D. MALDONADO ◽  
A. I. OLIVA
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Total Thickness ◽  
X Ray Diffraction ◽  
Atomic Concentration ◽  
Vacuum Oven ◽  
Force Microscopy ◽  
Atomic Force ◽  
Abrupt Changes ◽  
P Type

Au / Cu thin films (33–320 nm thickness) were deposited by thermal evaporation on p-type silicon (100) substrates. Two groups of these bimaterial films were alloyed into a vacuum oven by diffusion. The first group was prepared with 24% Au atomic concentration (i.e. 33, 96, 158, 224, and 320 nm as AuCu total thickness). The second group was prepared changing the Au atomic concentration from 10% to 90%, with 10% Au steps and similar total thickness (100 nm). Prepared alloys were characterized with atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and collinear four-probe techniques in order to obtain their morphology, stoichiometry, crystalline structure, and electrical resistivity, respectively. Particularly, electrical resistivity presented abrupt changes with the atomic concentration and the annealing temperature with important differences as compared with pure Au and Cu thin films.

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