Porous Amorphous Si Formation by the Etching of Single Crystal Si Substrates

1992 ◽  
Vol 259 ◽  
Author(s):  
T. George ◽  
R. P. Vasquez ◽  
S. S. Kim ◽  
R.W. Fathauer ◽  
W. T. Pike
Keyword(s):  
Photoelectron Spectroscopy ◽  
Light Emitting ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron ◽  
Spin Resonance ◽  
Amorphous Si ◽  
Si Films ◽  
P Type ◽  
Stain Etching

ABSTRACTThe nature of light-emitting porous Si layers produced by non-anodic stain etching of p-type (100) Si substrates is studied. The layers were characterized by transmission electron microscopy as being amorphous in nature. X-ray photoelectron spectroscopy and electron spin resonance measurements show these layers to be composed mainly of a-Si. The formation mechanism of the a-Si is explored using by stain etching SiGe ‘marker’ layers within epitaxially grown Si films and by high temperature annealing. These experiments provide strong evidence for a spontaneous crystalline-amorphous phase transformation during the etching process.

Photoluminescence of Chemically Etched Polycrystalline and Amorphous Si Thin Films

1993 ◽  
Vol 298 ◽  
Author(s):  
A. J. Steckl ◽  
J. Xu ◽  
H. C. Mogul
Keyword(s):  
Thin Films ◽  
Strong Relationship ◽  
Porous Si ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Si ◽  
Si Films ◽  
Uv Excitation ◽  
Highly Porous ◽  
Stain Etching

AbstractSi thin films were deposited on quartz at temperatures ( TD ) ranging from 540 to 640°C. X-ray diffraction indicates that films deposited at TD < 580°C are amorphous, while those deposited above 600°C are poly-crystalline with a <220> texture. The Si films were made porous by stain-etching in HF:HNO3:H2O. Only Si films deposited at 590°C and above show photoluminescence (PL), centered at ∼650-670 nm under UV excitation. Films deposited at TD < 580°C do not luminesce even after very long etch times, which produce a highly porous structure. The PL intensity and the x-ray signal follow a very similar trend with TD. It appears that a minimum level of crystallinity is required for photoemission in porous Si and that a strong relationship exists between them.

scholarly journals X-ray Photoelectron Spectroscopy (XPS) Analysis of Undoped ZnO and ZnO:Er Thin Films

2015 ◽  
Vol 16 (1) ◽  
pp. 13
Author(s):  
Iwan Sugihartono ◽  
Esmar Budi ◽  
Agus Setyo Budi
Keyword(s):  
Thin Films ◽  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Zno Thin Films ◽  
Xps Analysis ◽  
X Ray ◽  
Si Substrates ◽  
Ultrasonic Spray ◽  
P Type

Undoped ZnO and ZnO:Er  thin films were deposited on p-type Si substrates by ultrasonic spray pyrolisis (USP). Undoped and ZnO:Er thin films have been analyzed by using X-ray Photoelectron Spectroscopy (XPS). The results show that the XPS spectrum has two Er peak at ∼157 eV and ∼168 eV. The XPS Zn 2p spectrum of undoped ZnO and ZnO:Er thin films have binding energy for Zn 2p3/2 (~ 1021 eV) and Zn 2p1/2 (~1045eV) were found no shift in binding energy after the incorporation of Er. Meanwhile, after Er incorporates into ZnO, the O 1s spectrum is composed two peak of binding energy (BE) at ~530.5eV and the shoulder about 532.5 eV.Keywords: ZnO thin films, ZnO:Er, XPS, binding energy

Fast High-Density Low-Pressure Plasma Synthesis of GaN Nanocrystals

2005 ◽  
Vol 892 ◽  
Author(s):  
Rebecca Joy Anthony ◽  
Elijah Thimsen ◽  
Joe Johnson ◽  
Stephen A Campbell ◽  
Uwe Kortshagen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Plasma Synthesis ◽  
Light Emitting ◽  
X Ray ◽  
Light Emitting Devices ◽  
Transmission Electron ◽  
Solid State Devices ◽  
Bulk Gan ◽  
Synthesis Routes ◽  
Uv Range

AbstractGallium Nitride is of interest due to its direct bandgap, which allows for efficient emission in the near-UV range. Bulk GaN is already in use in solid-state devices that exploit its emissive properties, however, the promise of GaN nanocrystals as tunable emitters for use in light-emitting devices and lasers has led to the recent exploration of nanocrystalline GaN synthesis routes. Here we discuss the use of nonthermal plasmas for the synthesis of nanocrystalline pow-ders of GaN. The particles were examined using transmission electron microscopy and x-ray photoelectron spectroscopy.

scholarly journals Facile Synthesis of Highly Conductive Vanadium-Doped NiO Film for Transparent Conductive Oxide

2020 ◽  
Vol 10 (16) ◽  
pp. 5415
Author(s):  
Ashique Kotta ◽  
Hyung Kee Seo
Keyword(s):  
Electron Microscopy ◽  
Nickel Oxide ◽  
Photoelectron Spectroscopy ◽  
Transparent Conductive Oxide ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Conductive Oxide ◽  
P Type

Metal-oxide-based electrodes play a crucial role in various transparent conductive oxide (TCO) applications. Among the p-type materials, nickel oxide is a promising electrically conductive material due to its good stability, large bandgap, and deep valence band. Here, we display pristine and 3 at.%V-doped NiO synthesized by the solvothermal decomposition method. The properties of both the pristine and 3 at.%V:NiO nanoparticles were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), Raman spectroscopy, ultraviolet–visible spectroscopy (UV–vis), and X-ray photoelectron spectroscopy (XPS). The film properties were characterized by atomic force microscopy (AFM) and a source meter. Our results suggest that incorporation of vanadium into the NiO lattice significantly improves both electrical conductivity and hole extraction. Also, 3 at.%V:NiO exhibits a lower crystalline size when compared to pristine nickel oxide, which maintains the reduction of surface roughness. These results indicate that vanadium is an excellent dopant for NiO.

STUDY OF THE MICRO-STRUCTURE OF PtxSi ULTRA-THIN FILM

2011 ◽  
Vol 25 (21) ◽  
pp. 2925-2929 ◽  
Author(s):  
SHUANG LIU ◽  
CHARLES M. FALCO ◽  
ZHIYONG ZHONG
Keyword(s):  
Thin Film ◽  
Photoelectron Spectroscopy ◽  
Xps Analysis ◽  
X Ray Diffraction ◽  
Micro Structure ◽  
X Ray ◽  
Transmission Electron ◽  
Si Films ◽  
Pt Films ◽  
Thin Platinum

Ultra-thin platinum (Pt) films were deposited on Si (100) substrates at 160°C by magnetron sputtering and subsequently annealed to form silicides. The thickness of the Pt x Si films was found to be approximately 4 nm as determined by transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) analysis shows that these films consist of PtSi and Pt 2 Si phases, and a multi-layer configuration of SiO x/ PtSi/Pt 2 Si/Si was detected by angle-resolved XPS. However, the Pt 3 Si phase was not detected by X-ray diffraction (XRD).

Lateral Solid Phase Epitaxy of Evaporated Amorphous Si Films onto SiO2 Patterns

1983 ◽  
Vol 25 ◽  
Author(s):  
H. Yamamoto ◽  
H. Ishiwara ◽  
S. Furukawa ◽  
M. Tamura ◽  
T. Tokuyama
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Implantation ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Si Substrates ◽  
Transmission Electron ◽  
Amorphous Si ◽  
Si Films ◽  
Kinetics Of

ABSTRACTLateral solid phase epitaxy (L-SPE) of amorphous Si (a-Si) films vacuum-evaporated on Si substrates with SiO2 patterns has been investigated, in which the film first grows vertically in the regions directly contacted to the Si substrates and then grows laterally onto SiO2 patterns. It has been found from transmission electron microscopy and Nomarski optical microscopy that use of dense a-Si films, which are formed by evaporation on heated substrates and subsequent amorphization by Si+ ion implantation, is essentially important for L-SPE. The maximum L-SPE length of 5–6μm was obtained along the <010> direction after 10hourannealing at 600°C. The kinetics of the L-SPE growth has also been investigated.

Phase formation in Fe–Si thin-film diffusion couples

1992 ◽  
Vol 70 (10-11) ◽  
pp. 860-865 ◽  
Author(s):  
Douglas G. Ivey ◽  
Dashan Wang
Keyword(s):  
Protective Layer ◽  
Solubility Limit ◽  
Electron Beam Evaporation ◽  
Solid State Reactions ◽  
Plan View ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron ◽  
Amorphous Si ◽  
Thin Film Diffusion

The formation of FeSi2, as well as other iron silicides, from solid-state reactions of Fe thin films on Si substrates has been investigated. Iron layers, approximately 50 nm thick, were deposited by electron beam evaporation on <100> oriented Si substrates. Silicon (≈35 nm) and SiO2 (≈170 nm) layers were deposited on top of the Fe layer in the same evaporator without breaking the chamber vacuum. SiO2 acted as a protective layer during subsequent annealing in a nitrogen ambient. All annealed samples were examined using X-ray diffraction and transmission electron microscopy (TEM). Both plan view and cross section specimens were prepared for TEM. Detailed phase analysis was accomplished through the various electron diffraction and X-ray microanalysis techniques available with the TEM. Silicon dissolved readily in Fe, at temperatures lower than 300 °C, up to the solubility limit of ≈26 at%Si. FeSi formation followed (350 °C), with semiconducting FeSi2 forming at 500 °C. The Fe–amorphous Si interface was more reactive, with silicide formation occurring at lower annealing temperatures (300 °C). There was also evidence that FeSi2 formed directly from α-Fe and amorphous Si.

scholarly journals Characterization of Light Emitting Porous Polycrystalline Silicon Films

1996 ◽  
Vol 452 ◽  
Author(s):  
M. C. Poon ◽  
P. G. Han ◽  
J. K. O. Sin ◽  
H. Wong ◽  
P. K. Ko
Keyword(s):  
Photoelectron Spectroscopy ◽  
Polycrystalline Silicon ◽  
Amorphous Materials ◽  
Complex Structure ◽  
Laser Source ◽  
Light Emitting ◽  
Full Wave ◽  
Transmission Electron ◽  
Si Films ◽  
Polycrystalline Silicon Films

AbstractPolycrystalline silicon (poly-Si) thin films (∼700nm) were deposited by LPCVD, doped with 950°C phosphorous diffusion, and rendered porous by anodization and stain etching. From x-ray photoelectron spectroscopy, poly-Si films have atomic concentration of C(ls):0(ls):Si(2p) = 6%:15%:79%. However, porous poly-Si (PPS) films with weak photoluminescence (PL) have C:O:Si of 20%:38%:42%. For PPS films with strong PL, C:O:Si is 11%:38%:51%. From micro-Raman, scattered spectra for 632nm laser source has peak at 735nm and full wave half maximum (FWHM) of 76nm, and is similar to the PL spectra excited by 400nm uv laser source. High resolution transmission electron microscopy (TEM) study shows that PPS film is of complex structure and composes of numerous Si nano-crystals (1∼10nm) surrounded by amorphous materials.

Validation of the p-type Behavior of an Ag-doped ZnSe Film Grown Heteroepitaxially on GaAs(100) Substrate

2007 ◽  
Vol 1012 ◽  
Author(s):  
Takashi Narushima ◽  
Hiroaki Yanagita ◽  
Masahiro Orita
Keyword(s):  
Photoelectron Spectroscopy ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
Transmission Electron ◽  
Crystal Films ◽  
Probe Test ◽  
Hot Probe ◽  
P Type ◽  
Znse Single Crystal

AbstractTo validate p-type semiconducting behavior in Ag-doped ZnSe, single-crystal films were grown on GaAs(100) substrates using an evaporation method with ZnSe and Ag2Se powder sources. The heteroepitaxial relationship between ZnSe(100) and GaAs(100) was observed using X-ray diffraction and transmission electron microscopy; secondary phases containing silver or silver selenide were not detected. A film doped with Ag at 1 1020 atm·cm-3 had a conductivity of 1.5 x 10-5 S·cm-1. The hot-probe test indicated p-type polarity, with a clear and reproducible rectifying characteristic demonstrated by forming a ZnSe:Ag/p-GaAs:Zn junction. The work function of a ZnSe:Ag film measured by ultraviolet photoelectron spectroscopy was 6.3 eV. The ZnSe:Ag film is suitable as an injection layer in widegap semiconductor devices and organic light-emitting diodes.

Composite AgBr Colloidal Spheres/g-C3N4 Nanosheets: An Effective Light-Emitting Diode (LED) Irradiation Photocatalyst

2020 ◽  
Vol 20 (3) ◽  
pp. 1936-1940 ◽  
Author(s):  
Guochang Chen ◽  
Mingming Zhu ◽  
Lichun Wang ◽  
Xingrong Wu
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Light Emitting Diode ◽  
One Pot ◽  
Light Emitting ◽  
X Ray ◽  
Colloidal Spheres ◽  
Transmission Electron ◽  
The Stability ◽  
Led Irradiation

In this investigation, AgBr/g-C3N4 composite as an effective LED-irradiation photocatalyst was synthesized via a one-pot method. In this composite, the colloidal spheres of AgBr were uniformly dispersed on the g-C3N4 nanosheets, which were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis diffused reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The introduction of g-C3N4 nanosheets improved the stability and optimized the spatial charge carrier transfer compared to pristine AgBr, hence exhibited excellent activities toward the degradation of methyl orange (MO) as evidenced by the discoloration rate of MO by 94.8% after 120 min of irradiation. Also, the mechanism based on the band structures and microstructures of the catalysts was then proposed.

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