scholarly journals Effect the Temperature on Structure and Optical Properties for ZnS nanostructure Thin Film

2015 ◽  
Vol 11 (2) ◽  
pp. 3459-3472
Author(s):  
Nada K. Abbas ◽  
Khalid T. Al- Rasoul ◽  
Zainb J. Shanan
Keyword(s):  
Grain Size ◽  
Band Gap ◽  
Band Gap Energy ◽  
Temperature Reaction ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Zinc Blende ◽  
Absorption Studies ◽  
Two Peaks

ZnS nanocrystalline thin films by different temperature of reaction were prepared by chemical bath deposition using thiourea and zinc acetate as S2– and Zn2+ source. The optical absorption studies in the wavelength range 200–1100 nm show that band gap energy of samples 3.75 and 4.0 eV for different temperature reaction condition. The refractive index was estimated within the visible wavelength at 623 nm, it was 2.04 for sample 1 and its value will increase for sample 2 to be 2.55. The room temperature photoluminescence spectra of the films showed two peaks for all samples. We assigned the first peak due to band gap transitions while the latter was due to zinc vacancy in the films. Structural analysis using atomic force microscopy shows that the grain size for films were 73.2 and 87.34 nm. X-ray diffraction analysis indicates that both of them formed in the reaction bath have cubic zinc blende structure .The structural estimation shows variation in grain size 7nm and 20nm with different temperature reaction.

scholarly journals Morphological, structural and optical properties of MoO2 films electrodeposited on SnO2∣glass plate

2012 ◽  
Vol 10 (4) ◽  
pp. 1106-1118 ◽  
Author(s):  
Nijole Dukstiene ◽  
Dovile Sinkeviciute ◽  
Asta Guobiene
Keyword(s):  
Band Gap ◽  
Glass Plate ◽  
Sodium Molybdate ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Direct Band ◽  
Band Transition

AbstractMoO2 films were prepared by electrodeposition under potential controlled conditions from an aqueous alkaline solution of sodium molybdate. Optical microscopy showed that films of different morphology were deposited. The surface roughness and grain size were determined by atomic force microscopy. The characterization of as-deposited films by X-ray diffraction analysis revealed their amorphous nature. The optical constants of films were derived from transmittance spectra recorded in the 310–1100 nm wavelength range. All films were highly absorptive and showed a direct band to band transition. From the absorption edge data, the values of the optical band gap E g and the Urbach energy E U were determined based on Tauc’s model. The influence of film thickness on the extinction coefficient k, refractive index n, absorption coefficient a and the band gap energy E g was studied.

ANNEALING TIME EFFECT ON NANOSTRUCTURED n-ZnO/p-Si HETEROJUNCTION PHOTODETECTOR PERFORMANCE

2015 ◽  
Vol 22 (02) ◽  
pp. 1550027 ◽  
Author(s):  
NADIR. F. HABUBI ◽  
RAID. A. ISMAIL ◽  
WALID K. HAMOUDI ◽  
HASSAM. R. ABID
Keyword(s):  
Annealing Time ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
Force Microscopy ◽  
Atomic Force ◽  
Junction Type ◽  
P Type ◽  
Quartz Substrates ◽  
Two Peaks

In this work, n- ZnO /p- Si heterojunction photodetectors were prepared by drop casting of ZnO nanoparticles (NPs) on single crystal p-type silicon substrates, followed by (15–60) min; step-annealing at 600∘C. Structural, electrical, and optical properties of the ZnO NPs films deposited on quartz substrates were studied as a function of annealing time. X-ray diffraction studies showed a polycrystalline, hexagonal wurtizte nanostructured ZnO with preferential orientation along the (100) plane. Atomic force microscopy measurements showed an average ZnO grain size within the range of 75.9 nm–99.9 nm with a corresponding root mean square (RMS) surface roughness between 0.51 nm–2.16 nm. Dark and under illumination current–voltage (I–V) characteristics of the n- ZnO /p- Si heterojunction photodetectors showed an improving rectification ratio and a decreasing saturation current at longer annealing time with an ideality factor of 3 obtained at 60 min annealing time. Capacitance–voltage (C–V) characteristics of heterojunctions were investigated in order to estimate the built-in-voltage and junction type. The photodetectors, fabricated at optimum annealing time, exhibited good linearity characteristics. Maximum sensitivity was obtained when ZnO / Si heterojunctions were annealed at 60 min. Two peaks of response, located at 650 nm and 850 nm, were observed with sensitivities of 0.12–0.19 A/W and 0.18–0.39 A/W, respectively. Detectivity of the photodetectors as function of annealing time was estimated.

Nanocrystalline Solutions as Precursors to The Spray Deposition of Cdte Thin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Cdte Nanoparticles ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Cdte Thin Films

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.

Electrical Resistivity of Copper Films by Partially Ionized Beam Deposition

1996 ◽  
Vol 439 ◽  
Author(s):  
S. Han ◽  
K. H. Yoon ◽  
K. H. Kim ◽  
H. G. Jang ◽  
S. C. Choi ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Copper Films ◽  
X Ray Diffraction ◽  
Ion Energy ◽  
Xrd Pattern ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cu Film ◽  
Partially Ionized

AbstractCopper films on Si(100) were prepared by partially ionized beam at 0 kV and 3 kV acceleration voltages in order to investigate effects of ion energy on electrical property with thickness. X-ray diffraction(XRD) pattern analysis was used to investigate crystallinity of the copper films, microstructure by Scanning electron microscope(SEM) and surface roughness by atomic force microscopy(AFM). The crystallinity of the copper films grown at the 3 kV was more (111) textured than that at the 0 kV. The copper films grown at the both conditions had nearly same grain size below a thickness of 1000 Å. The 1800 Å Cu film grown at the 3 kV was 3 times rough than that at the 0 kV. The resistivity of copper films increased due to surface and grain boundary scattering, and the change of resistivity was discussed in terms of surface roughness, grain size and film density assisted by average depositing energy.

Grain Size Effect on Lattice of Ni Nanocrystals Prepared Through Polyol Method

2008 ◽  
Vol 8 (8) ◽  
pp. 4127-4131 ◽  
Author(s):  
G. S. Okram ◽  
Kh. Namrata Devi ◽  
H. Sanatombi ◽  
Ajay Soni ◽  
V. Ganesan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
Polyol Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scanning Electron

Nanocrystalline nickel powders were prepared with grain size 'd' in the range 40–100 nm diameters through polyol method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used for characterization. XRD of the prepared samples consistently matched with standard fcc structure of nickel without any impurity peak. Detailed analysis and calculations using Scherrer equation for (111) peak revealed systematic increase in line width and peak shifting towards lower diffraction 2θ angles with decrease in nickel to ethylene glycol mole ratio. Different values of d estimated from various peaks of each sample suggested associated microstrains in the nanograins. Values of d estimated from X-ray diffraction patterns were compared with those obtained from atomic force microscopy and scanning electron microscopy results, and discussed. Observed lattice expansion is explained, on the basis of a theoretical model of linear elasticity.

scholarly journals Synthesis and Photonics Applications of Afzelechin Conjugated Silver Nanoparticles

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1295
Author(s):  
Shahid Ali ◽  
Muhammad Rahim ◽  
Perveen Fazil ◽  
Malik Shoaib Ahmad ◽  
Azeem Ullah ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Band Gap ◽  
Band Gap Energy ◽  
Visible Absorption ◽  
Force Microscopy ◽  
Atomic Force ◽  
Uv Visible ◽  
Size And Morphology ◽  
Average Size ◽  
20 Nm

The silver nanoparticles were synthesized, functionalized with afzelechin and characterized using UV-Visible spectroscopy. A difference of 20 nm was observed in surface plasmon resonance of bare and functionalized silver nanoparticles which indicates afzelechin conjugation with silver nanoparticles. The atomic force microscopy (AFM) technique was used for the determination of the size and morphology of synthesized silver nanoparticles. The afzelechin conjugated silver nanoparticles were spherical and their sizes ranged from 3 to 10 nm with an average size of 8 nm while the bare silver nanoparticles were also spherical and their sizes ranged from 3 to 10 nm with an average size of 6 nm. The average sizes were also calculated by fitting their UV-Visible absorption spectra. Fitting is based on the Mie and Mie Gans models, which deduced that afzelechin conjugated silver nanoparticles were 96.5% spherical and 3.5% spheroidal with an average size of 5 nm while bare silver nanoparticles were 100% spherical with an average size of 4 nm. Both the fitting model as well as the AFM results showed a difference of 3 nm between the sizes of afzelechin conjugated silver nanoparticles while 2 nm differences was observed for bare silver nanoparticles. The band gap energy of afzelechin conjugated silver nanoparticles and bare silver nanoparticles were calculated via Tauc’s equation and were found to be 5.1 eV and 5.4 eV, respectively. A difference of 0.3 eV was observed in band gap energies of afzelechin conjugated silver nanoparticles and bare silver nanoparticles.

Electroplated CuO Thin Films from High Alkaline Solutions

2011 ◽  
Vol 15 (1) ◽  
pp. 49-55
Author(s):  
V. Dhanasekaran ◽  
T. Mahalingam ◽  
S. Rajendran ◽  
Jin Koo Rhee ◽  
D. Eapen
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Film Thickness ◽  
Structural Characteristics ◽  
Band Gap Energy ◽  
Alkaline Solutions ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Microstructural Parameters ◽  
Atomic Force

CuO thin films were coated on ITO substrates by an electrodeposition route through potentiostatic mode. The electrodeposited CuO thin films were characterized and the role of copper sulphate concentration on the structural, morphological and optical properties of the CuO films was studied. Film thickness was measured by a stylus profilometer and found to be in the range between 800 and 1400 nm. The structural characteristics studies were carried out using X-ray diffraction and found that the films are polycrystalline in nature with a cubic structure. The preferential orientation of CuO thin films is found to be along (111) plane. The estimated microstructural parameters revealed that the crystallite size increases whereas the number of crystallites per unit area decreases with increasing film thickness. SEM studies show that the grain sizes of CuO thin films vary between 100 and 150 nm and also morphologies revealed that the electrodeposited CuO exhibits uniformity in size and shape. The surface roughness is estimated 15 nm of the CuO film were studied by atomic force microscopy. Optical properties of the films were analyzed from absorption and transmittance studies. The optical band gap energy was determined to be 1.5 eV from absorption coefficient. The variation of refractive index (n), extinction coefficient (k), with wavelength was studied and the results are discussed.

Microstructural features and mechanical properties of 18 MeV He+ ions irradiated pure Zr

2016 ◽  
Vol 30 (32n33) ◽  
pp. 1650395
Author(s):  
Mohsin Rafique ◽  
San Chae ◽  
Yong-Soo Kim
Keyword(s):  
Grain Size ◽  
Irradiation Dose ◽  
Dose Range ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Pure Zirconium ◽  
Higher Doses

Samples of pure zirconium (Zr) were irradiated by 18 MeV helium (He[Formula: see text]) ions in the dose range 0.00162–0.0324 dpa at 373 K by using Cyclotron accelerator. The atomic force microscopy (AFM) results indicated an increase in average surface roughness of Zr by increasing the irradiation dose. The AFM images revealed nucleation and growth of nano- and micro-size hillocks at lower doses (0.00162–0.00324 dpa), whereas formation of a volcano-like cavities and craters was observed within these hillocks by increasing the radiation dose from 0.00324 to 0.0324 dpa. The high-resolution X-ray diffraction (XRD) results showed a variation in the intensities and positions of the diffraction peaks after the irradiation. The transmission electron microscopy (TEM) results reported a significant decrease in the grain size after the He[Formula: see text] irradiation. The values of grain size, calculated using the TEM, were found to be in good agreement with the crystallite size calculated using the XRD analysis. The yield stress (YS) was increased by increasing the irradiation dose up to 0.0162 dpa, however, the YS exhibited a decreasing trend with a further increase of the dose. The changes in YS were elucidated by grain size reduction and localized heating at higher doses.

Electrical Resistivity of Copper Films by Partially Ionized Beam Deposition

1996 ◽  
Vol 438 ◽  
Author(s):  
S. Han ◽  
K. H. Yoon ◽  
K. H. Kim ◽  
H. G. Jang ◽  
S. C. Choi ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Copper Films ◽  
X Ray Diffraction ◽  
Ion Energy ◽  
Xrd Pattern ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cu Film ◽  
Partially Ionized

AbstractCopper films on Si(100) were prepared by partially ionized beam at 0 kV and 3 kV acceleration voltages in order to investigate effects of ion energy on electrical property with thickness. X-ray diffraction(XRD) pattern analysis was used to investigate crystallinity of the copper films, microstructure by Scanning electron microscope(SEM) and surface roughness by atomic force microscopy(AFM). The crystallinity of the copper films grown at the 3 kV was more (111) textured than that at the 0 kW. The copper films grown at the both condiitions had nearly same grain size below a thickness of 1000 Å. The 1800 Å Cu film grown at the 3 kV was 3 times rough than that at the 0 kV. The resistivity of copper films increased due to surface and grain boundary scattering, and the change of resistivity was discussed in terms of surface roughness, grain size and film density assisted by average depositing energy.

Nanoindention studies of DC sputtered Cu and Cu/Cr thin films

2001 ◽  
Vol 672 ◽  
Author(s):  
G. Wei ◽  
J. Du ◽  
A. Rar ◽  
J. A. Barnard
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
Surface Morphology ◽  
Film Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Grain Size And Orientation

ABSTRACTThe nanoindentation behavior of DC magnetron sputtered 10 nm Cu and 10 nm Cu/2 nm Cr thin films deposited on Si (100) has been studied using a Hysitron nanomechanical system. X- ray diffraction and X-ray reflectivity were used to measure the film structure and film thickness, respectively. The grain size and orientation of Cu and Cu/Cr thin films were measured by TEM. Atomic force microscopy (AFM) was used to evaluate the surface morphology and roughness. At the same load, the nanoindentaion displacement of Cu/Cr is smaller than that for Cu, i.e., the 2nm thick Cr underlayer enhances the hardness of Cu. X-ray, TEM, and AFM results show that the grain size of Cu/Cr (< 15 nm) is actually larger than Cu (∼ 3 nm) indicating that the inverse Hall-Petch relationship may be operative.

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