Zinc Oxide Nanostructure Synthesis on Si(100) by Vapor Phase Transport and the Effect of Antimony Doping on Photoelectric Properties, Morphology, and Structure

ABSTRACTZinc Oxide (ZnO) has been shown to exhibit semiconducting and piezoelectric dual properties. This has led to a large commercial demand on ZnO for optoelectronics that operate at the blue-ultraviolet regions. Consequently, varying techniques have been devised to create different nanostructures of ZnO. Here, the single step synthesis of ZnO nanostructures was performed on Si(100) substrates with a thin ZnO seed-layer. A modified chemical vapor deposition (CVD) method was developed to accomplish the structure formation. Sb doping of the structures in the gas phase was performed to study its effects on structure and optoelectronic properties. Different structures were realized including nanofilaments, nanoparticles, microflowers, nanorods, nanotubes, and nanocolumns. Only nanorods/columns, and nanotubes are shown in this work. Morphology was examined using scanning electron microscopy (SEM). Energy-dispersive X-ray spectroscopy (EDS) and X-ray powder diffraction (XRD) were used for structural studies. Optoelectronic properties were explored using room-temperature photoluminescence (PL) spectroscopy. PL data show the relative decrease in the number of defects and increase in crystal quality upon increasing reaction time. Significant structural effects were also observed upon doping. Some structural defects might be attributed to the diffusion of Sb ions into the lattices of ZnO, replacement of Zn by Sb, and ionic radii difference. These stacking faults are most likely the reason behind the dominance and broadening of DLE peak.

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Growth of Highly Oriented Zinc Oxide Thin Films by Plasma Enhanced Chemical Vapor Deposition

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.321-323.1687 ◽

2006 ◽

Vol 321-323 ◽

pp. 1687-1690 ◽

Cited By ~ 1

Author(s):

Hee Joon Kim ◽

Dong Young Jang ◽

Prem Kumar Shishodia ◽

Akira Yoshida

Keyword(s):

Thin Films ◽

Zinc Oxide ◽

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Photoelectron Spectroscopy ◽

Visible Region ◽

Chemical Vapor ◽

Zno Films ◽

X Ray ◽

Crystalline Films

In the paper, zinc oxide (ZnO) thin films are deposited by plasma enhanced chemical vapor deposition (PECVD) at different substrate temperatures. The ZnO films are characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The analysis results indicate that highly crystalline films with high orientation can be obtained at a substrate temperature of 300 oC with 50 ml/min flow rate from Diethylzinc (DEZ). Furthermore, the investigation of optical property shows that ZnO films are transparent, and the peak transmittance in the visible region is as high as 85%.

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Structural Defects and Critical Electric Field in 3C-SiC

Materials Science Forum ◽

10.4028/www.scientific.net/msf.527-529.431 ◽

2006 ◽

Vol 527-529 ◽

pp. 431-434 ◽

Cited By ~ 2

Author(s):

Michael A. Capano ◽

A.R. Smith ◽

Byeung C. Kim ◽

E.P. Kvam ◽

S. Tsoi ◽

...

Keyword(s):

Raman Spectroscopy ◽

Electric Field ◽

Lattice Mismatch ◽

Defect Density ◽

Chemical Vapor ◽

Structural Defects ◽

X Ray ◽

Transmission Electron ◽

Current Voltage ◽

P Type

3C-SiC p-type epilayers were grown to thicknesses of 1.5, 3, 6 and 10 μm on 2.5° off-axis Si(001) substrates by chemical vapor deposition (CVD). Silane and propane were used as precursors. Structural analysis of epilayers was performed using transmission electron microscopy (TEM), high-resolution x-ray diffractometry (HRXRD), and Raman spectroscopy. TEM showed defect densities (stacking faults, twins and dislocations) decreasing with increasing distance from the SiC/Si interface as the lattice mismatch stress is relaxed. This observation was corroborated by a monotonic decrease in HRXRD peak width (FWHM) from 780 arcsecs (1.5 μm thick epilayer) to 350 arcsecs (10 μm thick epilayer). Significant further reduction in x-ray FWHM is possible because the minimum FWHM detected is greater than the theoretical FWHM for SiC (about 12 arcsecs). Raman spectroscopy also indicates that the residual biaxial in-plane strain decreases with increasing epilayer thickness initially, but becomes essentially constant between 6 and 10 μm. Structural defect density shows the most significant reduction in the first 2 μm of growth. Phosphorus implantation was used to generate n+/p junctions for the measurement of the critical electric field in 3C-SiC. Based on current-voltage analyses, the critical electric field in p-type 3C-SiC with a doping of 2x1017 cm-3 is 1.3x106 V/cm.

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Correlation between Microstructure and Chemical Composition of Zinc Oxide Gas Sensor Layers and Their Gas-Sensitive Properties in Chlorine Atmosphere

10.20944/preprints202011.0378.v1 ◽

2020 ◽

Author(s):

Marta Fiedot-Toboła ◽

Patrycja Suchorska-Woźniak ◽

Kamila Startek ◽

Olga Rac-Rumijowska ◽

Monika Kwoka ◽

...

Keyword(s):

Crystal Structure ◽

Zinc Oxide ◽

Chemical Composition ◽

Specific Surface ◽

Gas Sensor ◽

Photoelectron Spectroscopy ◽

Structural Defects ◽

X Ray ◽

Conductance Method ◽

The Impact

In the article we present the results concerning the impact of structural and chemical properties of zinc oxide in various morphological forms, on its gas-sensitive properties tested in an atmosphere containing a very aggressive gas such as chlorine. Two types of ZnO sensor layers obtained by two different technological methods were used. Their morphology, crystal structure, specific surface area, porosity, surface chemistry and structural defects were characterized, and then compared with gas-sensitive properties in a chlorine-containing atmosphere. To achieve this goal scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL) methods were used. The sensing properties of obtained active layers were tested by temperature stimulated conductance method (TSC). We have noticed that their response in chlorine atmosphere is not determined by the size of the specific surface or porosity. The obtained results showed that the structural defects of ZnO crystals play the most important role in chlorine detection. We demonstrated that the Cl2 adsorption is a concurrent process to oxygen adsorption. Both of them occur on the same active species (oxygen vacancies). They concentration is higher on the side planes of the zinc oxide crystal than the others. Thanks to the conducted studies authors demonstrated that to develop a new gas sensor devices not only changing of active layer chemical composition but also controlling its crystal structure and morphology could be used.

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Correlation between Microstructure and Chemical Composition of Zinc Oxide Gas Sensor Layers and Their Gas-Sensitive Properties in Chlorine Atmosphere

Sensors ◽

10.3390/s20236951 ◽

2020 ◽

Vol 20 (23) ◽

pp. 6951

Author(s):

Marta Fiedot-Toboła ◽

Patrycja Suchorska-Woźniak ◽

Kamila Startek ◽

Olga Rac-Rumijowska ◽

Rafał Szukiewicz ◽

...

Keyword(s):

Zinc Oxide ◽

Specific Surface ◽

Gas Sensor ◽

Photoelectron Spectroscopy ◽

Structural Defects ◽

Concurrent Process ◽

Detection Mechanism ◽

X Ray ◽

Conductance Method ◽

The Impact

In this article, we present results concerning the impact of structural and chemical properties of zinc oxide in various morphological forms and its gas-sensitive properties, tested in an atmosphere containing a very aggressive gas such as chlorine. The aim of this research was to understand the mechanism of chlorine detection using a resistive gas sensor with an active layer made of zinc oxide with a different structure and morphology. Two types of ZnO sensor layers obtained by two different technological methods were used in sensor construction. Their morphology, crystal structure, specific surface area, porosity, surface chemistry and structural defects were characterized, and then compared with gas-sensitive properties in a chlorine-containing atmosphere. To achieve this goal, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL) methods were used. The sensing properties of obtained active layers were tested by the temperature stimulated conductance method (TSC). We have noticed that their response in a chlorine atmosphere is not determined by the size of the specific surface or porosity. The obtained results showed that the structural defects of ZnO crystals play the most important role in chlorine detection. We demonstrated that Cl2 adsorption is a concurrent process to oxygen adsorption. Both of them occur on the same active species (oxygen vacancies). Their concentration is higher on the side planes of the zinc oxide crystal than the others. Additionally, ZnO sublimation process plays an important role in the chlorine detection mechanism.

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One-Step Cost-Effective Growth of High-Quality Epitaxial Ge Films on Si (100) Using a Simplified PECVD Reactor

Electronic Materials ◽

10.3390/electronicmat2040033 ◽

2021 ◽

Vol 2 (4) ◽

pp. 482-494

Author(s):

Jignesh Vanjaria ◽

Venkat Hariharan ◽

Arul Chakkaravarthi Arjunan ◽

Yanze Wu ◽

Gary S. Tompa ◽

...

Keyword(s):

Film Growth ◽

High Vacuum ◽

Chemical Vapor ◽

Cost Effective ◽

Single Step ◽

Film Deposition ◽

Ultra High Vacuum ◽

Ex Situ ◽

High Quality ◽

X Ray

Heteroepitaxial growth of Ge films on Si is necessary for the progress of integrated Si photonics technology. In this work, an in-house assembled plasma enhanced chemical vapor deposition reactor was used to grow high quality epitaxial Ge films on Si (100) substrates. Low economic and thermal budget were accomplished by the avoidance of ultra-high vacuum conditions or high temperature substrate pre-deposition bake for the process. Films were deposited with and without plasma assistance using germane (GeH4) precursor in a single step at process temperatures of 350–385 °C and chamber pressures of 1–10 Torr at various precursor flow rates. Film growth was realized at high ambient chamber pressures (>10−6 Torr) by utilizing a rigorous ex situ substrate cleaning process, closely controlling substrate loading times, chamber pumping and the dead-time prior to the initiation of film growth. Plasma allowed for higher film deposition rates at lower processing temperatures. An epitaxial growth was confirmed by X-Ray diffraction studies, while crystalline quality of the films was verified by X-ray rocking curve, Raman spectroscopy, transmission electron microscopy and infra-red spectroscopy.

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NANOSTRUCTURAL ZnO FABRICATED BY VAPOR-PHASE TRANSPORT IN AIR

International Journal of Modern Physics B ◽

10.1142/s0217979204023829 ◽

2004 ◽

Vol 18 (02) ◽

pp. 225-232 ◽

Cited By ~ 4

Author(s):

C. X. XU ◽

X. W. SUN ◽

B. J. CHEN ◽

C. Q. SUN ◽

B. K. TAY

Keyword(s):

Zinc Oxide ◽

Growth Time ◽

Zinc Oxide Nanostructures ◽

X Ray Diffraction ◽

Vapor Phase Transport ◽

X Ray ◽

Zno Nanostructure ◽

Oxide Nanostructures ◽

Vapor Liquid Solid Mechanism ◽

Phase Transport

Nanostructural zinc oxide has been successfully fabricated by heating the mixture of ZnO and graphite powders in air. The growth of these zinc oxide nanostructures with respect to the growing time and temperature has been studied. The morphologies and the crystal structures have been characterized by scanning electronic microscopy and the X-ray diffraction. The results indicated that ZnO nanostructure formed mainly along the crystal orientation [002] on silicon substrate at moderate temperatures. The crystallization was improved by prolonging growth time and the morphologies mainly depended on the distribution of the growth temperature. The growth process was attributed to vapor-liquid-solid mechanism.

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Reduction of Structural Defects in Ge Epitaxially Grown on Nano-Structured Si Islands on SOI Substrate

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.205-206.400 ◽

2013 ◽

Vol 205-206 ◽

pp. 400-405

Author(s):

Peter Zaumseil ◽

Yuji Yamamoto ◽

Markus Andreas Schubert ◽

Thomas Schroeder ◽

Bernd Tillack

Keyword(s):

Electron Microscopy ◽

Vapor Deposition ◽

Strain State ◽

Chemical Vapor ◽

Structural Defects ◽

Misfit Dislocations ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Nanostructured Si

One way to further increase performance and/or functionality of Si micro-and nanoelectronics is the integration of alternative semiconductors on silicon (Si). We studied the Ge/Si heterosystem with the aim to realize a Ge deposition free of misfit dislocations and with low content of other structural defects. Ge nanostructures were selectively grown by chemical vapor deposition on periodic Si nanoislands (dots and lines) on SOI substrate either directly or with a thin (about 10 nm) SiGe buffer layer. The strain state of the structures was measured by different laboratory-based x-ray diffraction techniques. It was found that a suited SiGe buffer improves the compliance of the Si compared to direct Ge deposition; plastic relaxation during growth can be prevented, and fully elastic relaxation of the structure can be achieved. Transmission electron microscopy confirms that the epitaxial growth of Ge on nanostructured Si is free of misfit dislocations.

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Effect of sample thickness on the structural and optical properties of Polyvinyl Chloride/Zinc Oxide Nanocomposite Films for photocatalysis application

10.21203/rs.3.rs-811397/v1 ◽

2021 ◽

Author(s):

aimane guedri ◽

Mourad ZAABAT ◽

Boubekeur BOUDINE ◽

Abdelkader HAFDALLAH

Keyword(s):

Zinc Oxide ◽

Optical Properties ◽

Polyvinyl Chloride ◽

Spin Coating ◽

Visible Region ◽

Nanocomposite Films ◽

Structural Defects ◽

X Ray Diffraction ◽

Lower Efficiency ◽

X Ray

Abstract Considered Technique spin coating of the most important techniques used to prepare thin films because it is easy to use and inexpensive since it is closely dependent on the number of layers deposited. This work aims to study the effect of samples thickness for nanocomposites of polyvinyl chloride doped with zinc oxide nanoparticles on the structural, optical properties, and photocatalytic activities. Nanocomposite films of polyvinyl chloride (PVC) - zinc oxide (ZnO) with a different number of the deposited layers (15, 20, 25, and 30 layers) were synthesized by a sol-gel method (spin coating) using tetrahydrofuran as a solvent, and investigated by various techniques. X-ray diffraction measurements indicated in the case of 15, 20, and 25 layers do not clearly show the presence of diffraction peaks. On the other hand, in the case of 30 layers, the presence of several peaks is observed, which testify to the presence of ZnO crystallites of wurtzite structure in PVC films. The size of the crystallites is almost equal to 32 nm depending on the working conditions. Raman and infrared spectra confirmed the result of X-ray diffraction on the incorporation of ZnO crystallites in the films produced by showing peaks corresponding to the modes of vibration of the crystal lattice of the ZnO doping semiconductor. Optical transmittance spectra have shown that The layers obtained have an optical transmission varying from 75 to 86% in the visible region of the spectrum. The values of the band gap energies, determined from the transmission spectra for the films deposited on glass, vary between 3.45 and 3.94 eV. The Photoluminescence spectra of ZnO/PVC nanocomposites studied revealed a strong ultraviolet and green luminescence, attributed to structural defects in the zinc oxide. The photocatalytic reaction has been shown using MB in the UV irradiation action of films stacked in an MB solution. The result showed that the 30-layer (PVC / ZnO) sample gave an efficiency to remove MB of 79% at 60 min, Similar to other samples which gave a lower efficiency.

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PbI2 Single Crystal Growth and Its Optical Property Study

Crystals ◽

10.3390/cryst9110589 ◽

2019 ◽

Vol 9 (11) ◽

pp. 589 ◽

Cited By ~ 2

Author(s):

Lin ◽

Guo ◽

Dai ◽

Lin ◽

Hsu

Keyword(s):

Band Gap ◽

Chemical Vapor ◽

Band Gap Energy ◽

Chemical Vapor Transport ◽

X Ray Diffraction ◽

X Ray ◽

Gap Energy ◽

Photoelectric Properties ◽

Metal Semiconductor Metal ◽

Excitonic Transition

In this work, we used the chemical vapor transport (CVT) method to grow PbI2 crystals using iodine as a self-transporting agent. The crystals’ structure, composition, and uniformity were confirmed by X-ray diffraction (XRD) and electron probe microanalysis (EPMA) measurements. We investigated the band gap energy using absorption spectroscopy measurements. Furthermore, we explored the temperature dependence of the band gap energy, which shifts from 2.346 eV at 300 K to 2.487 eV at 20 K, and extracted the temperature coefficients. A prototype photodetector with a lateral metal–semiconductor–metal (MSM) configuration was fabricated to evaluate its photoelectric properties using a photoconductivity spectrum (PC) and persistent photoconductivity (PPC) experiments. The resonance-like PC peak indicates the excitonic transition in absorption. The photoresponse ILight/IDark-1 is up to 200%.

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