Amorphous and Microcrystalline SiC as New Synthetic Wide Gap Semiconductors

1992 ◽  
Vol 242 ◽  
Author(s):  
Y. Hamakawa ◽  
H. Okamoto
Keyword(s):  
Energy Gap ◽  
Ion Beam ◽  
Technological Evolution ◽  
Microcrystalline Silicon ◽  
Technical Data ◽  
Preparation Conditions ◽  
Current State ◽  
Valency Electron ◽  
Impurity Doping ◽  
P Type

ABSTRACTA review is given on recent progress in amorphous and microcrystalline silicon-carbide (a-SiC, nc-SiC) semiconductors and their technological applications to optoelectronic functional devices. Firstly, some significant properties in this alloy as a new synthetic material are pointed out with recent advances of thin film technologies, such as plasma CVD, ECR-CVD and ion-beam CVD etc. There exists an energy gap controllability from 1.7eV to 3.6 eV with retaining the valency electron control from n-type through i- to p-type semiconductors. While its conductivity can also be controlled more than ten order of magnitudes, e.g., from 10-9to 102 Scm-1 by controlling the impurity doping and preparation conditions.Secondly, a series of technical data on the electronic and optoelectronic properties of a-Si, C1−x C1−x and μ-SiC are demonstrated from recent achievements. In the final part of the paper, current state of the art in the field of optoelectronic applications from live technologies on amorphous silicon solar cells. a-SiC visible light LED and EL devices are reviewed. A technological evolution from “microelectronics” to “macroelectronlcs” will be discussed.

Optoelectronics and Photovoltaic Applications of Microcrystalline Sic

1989 ◽  
Vol 164 ◽  
Author(s):  
Y. Hamakawa ◽  
Y. Matsumoto ◽  
G. Hirata ◽  
H. Okamoto
Keyword(s):  
Electron Cyclotron Resonance ◽  
Energy Gap ◽  
Light Emitting Diode ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Heterojunction Solar Cells ◽  
Plasma Chemical Vapor Deposition ◽  
Ecr Plasma ◽  
Valency Electron ◽  
P Type

AbstractA review is given of the electrical and optical properties of hydrogenated microcrystalline silicon carbide (μc-SiC:H) films prepared by ECR (Electron Cyclotron Resonance) plasma chemical vapor deposition. The material produced with the ECR plasma technology has a very wide energy gap from 2 to 2.8 eV with good valency electron controllability, e.g., a dark conductivity as high as 10 Scmg− which is more than seven orders of magnitude larger than that of amorphous SiC:H.Employing this material as a wide gap heterojunction window, 15.4% and 12.0% conversion efficiencies have been achieved with the structures of ITO/p type μc-SiC:H/n type poly-Si and p type vc-SiC:H/i type a-Si:H/n type Pc-Si:H heterojunction solar cells, respectively. The successful development of a visible light thin film light emitting diode show the promise of microcrystalline materials for optoelectronic applications.

The Novel Dopant Profile Inspection Methodology by FIB

2010 ◽  
Author(s):  
Po Fu Chou ◽  
Li Ming Lu
Keyword(s):  
High Resolution ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Real Sample ◽  
Physical Analysis ◽  
The Novel ◽  
High Contrast ◽  
Dopant Profile ◽  
P Type

Abstract Dopant profile inspection is one of the focused ion beam (FIB) physical analysis applications. This paper presents a technique for characterizing P-V dopant regions in silicon by using a FIB methodology. This technique builds on published work for backside FIB navigation, in which n-well contrast is observed. The paper demonstrates that the technique can distinguish both n- and p-type dopant regions. The capability for imaging real sample dopant regions on current fabricated devices is also demonstrated. SEM DC and FIB DC are complementary methodologies for the inspection of dopants. The advantage of the SEM DC method is high resolution and the advantage of FIB DC methodology is high contrast, especially evident in a deep N-well region.

scholarly journals Stable Cu2O Photoelectrodes by Reactive Ion Beam Sputter Deposition

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Ching-Hsiu Chen ◽  
Assamen Ayalew Ejigu ◽  
Liang-Chiun Chao
Keyword(s):  
Electrode Materials ◽  
Variable Temperature ◽  
Ion Beam ◽  
Sputter Deposition ◽  
Flow Rates ◽  
Vacancy Defects ◽  
Photoluminescence Study ◽  
P Type ◽  
Quartz Substrates ◽  
Ion Beam Sputter Deposition

Cu2O has been deposited on quartz substrates by reactive ion beam sputter deposition. Experimental results show that by controlling argon/oxygen flow rates, both n-type and p-type Cu2O samples can be achieved. The bandgap of n-type and p-type Cu2O were found to be 2.3 and 2.5 eV, respectively. The variable temperature photoluminescence study shows that the n-type conductivity is due to the presence of oxygen vacancy defects. Both samples show stable photocurrent response that photocurrent change of both samples after 1,000 seconds of operation is less than 5%. Carrier densities were found to be 1.90 × 1018 and 2.24 × 1016 cm−3 for n-type and p-type Cu2O, respectively. Fermi energies have been calculated, and simplified band structures are constructed. Our results show that Cu2O is a plausible candidate for both photoanodic and photocathodic electrode materials in photoelectrochemical application.

Optical and electrical properties of p-type zinc oxide thin films synthesized by ion beam assisted deposition

2005 ◽  
Vol 492 (1-2) ◽  
pp. 203-206 ◽  
Author(s):  
Zhi Yan ◽  
Zhi Tang Song ◽  
Wei Li Liu ◽  
Qing Wan ◽  
Fu Min Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Electrical Properties ◽  
Ion Beam ◽  
Optical And Electrical Properties ◽  
Oxide Thin Films ◽  
Ion Beam Assisted Deposition ◽  
P Type

Superconducting State

2021 ◽  
Author(s):  
Vladimir Kresin ◽  
Sergei Ovchinnikov ◽  
Stuart Wolf
Keyword(s):  
Critical Temperature ◽  
Energy Gap ◽  
Microscopic Theory ◽  
Record Values ◽  
Theoretical Treatment ◽  
Many Body ◽  
Many Body Theory ◽  
Current State ◽  
Superconducting Compounds ◽  
Body Theory

For the past almost fifty years, scientists have been trying to explain the phenomenon of superconductivity. The mechanism is the key ingredient of microscopic theory, which was developed by Bardeen, Cooper, and Schrieffer in 1957. The theory also introduced the basic concepts of pairing, coherence length, energy gap, and so on. Since then, microscopic theory has undergone an intensive development. This book provides a very detailed theoretical treatment of the key mechanisms of superconductivity, including the current state of the art (phonons, magnons, plasmons). In addition, the book contains descriptions of the properties of the key superconducting compounds that are of the most interest for science and applications. For many years, there has been a search for new materials with higher values of the main parameters, such as the critical temperature and critical current. At present, the possibility of observing superconductivity at room temperature has become perfectly realistic. That is why the book is especially concerned with high-Tc systems such as high-Tc oxides, hydrides with record values for critical temperature under high pressure, nanoclusters, and so on. A number of interesting novel superconducting systems have been discovered recently, including topological materials, interface systems, and intercalated graphene. The book contains rigorous derivations based on statistical mechanics and many-body theory. The book also provides qualitative explanations of the main concepts and results. This makes the book accessible and interesting for a broad audience.

Low temperature processed p-type bottom gate microcrystalline silicon thin film transistors

2010 ◽  
pp. NA-NA
Author(s):  
O. Moustapha ◽  
A. Abramov ◽  
D. Daineka ◽  
M. Oudwan ◽  
Y. Bonnassieux ◽  
...  
Keyword(s):  
Thin Film ◽  
Low Temperature ◽  
Thin Film Transistors ◽  
Microcrystalline Silicon ◽  
Silicon Thin Film ◽  
P Type ◽  
Bottom Gate

Gold nanoclusters reductively deposited on porous silicon: morphology and electronic structures

1998 ◽  
Vol 76 (11) ◽  
pp. 1707-1716 ◽  
Author(s):  
I Coulthard ◽  
S Degen ◽  
Y -J Zhu ◽  
T K Sham
Keyword(s):  
Gold Nanoparticles ◽  
Porous Silicon ◽  
Photoelectron Spectroscopy ◽  
Gold Nanoclusters ◽  
Gold Complex ◽  
X Ray Diffraction ◽  
Complex Ions ◽  
X Ray ◽  
Preparation Conditions ◽  
P Type

Utilizing porous silicon as a reducing agent and a substrate, gold complex ions [AuCl4]- were reduced from aqueous solution to produce nanoparticles of gold upon the surface of porous silicon. Scanning electron microscopy (SEM) was utilized to study the morphology of the porous silicon layers and the deposits of gold nanoparticles. It is found that preparation conditions have a profound effect on the morphology of the deposits, especially on porous silicon prepared from a p-type wafer. The gold nanoparticles, varying from micrometric aggregates of clusters of the order of 10 nm, to a distribution of nearly spherical clusters of the order of 10 nm, to strings of ~10 nm were observed and compared to bulk gold metal using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). These techniques confirm and complement the SEM findings. The potential for this reductive deposition technique is noted.Key words: gold nanostructures, reductive deposition, porous silicon, morphology, X-ray spectroscopy.

Improvement on Thermoelectric Characteristics of Layered Nanostructure by Ion Beam Bombardment

2006 ◽  
Vol 929 ◽  
Author(s):  
Bangke Zheng ◽  
S. Budak ◽  
C. Muntele ◽  
Z. Xiao ◽  
S. Celaschi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Electric Conductivity ◽  
Ion Beam ◽  
Thermo Electric ◽  
Super Lattice ◽  
Before And After ◽  
The Cross ◽  
Nano Cluster ◽  
P Type

ABSTRACTWe made p-type nanoscale super lattice thermoelectric cooling devices which consist of multiple periodic layers of Si1−x Gex / Si, The thickness of each layer ranges between 10 and 50 nm. The super lattice was bombarded by 5 MeV Si ion with different fluencies aiming to form nano-cluster quantum dot structures. We estimated the thermo-electric efficiency of the so fabricated devices, measuring the thin film cross plane thermal conductivity by the 3rd harmonic method, measuring the cross plane Seebeck coefficient, and finally measuring the cross plane electric conductivity before and after ion bombardment. As predicted, the thermo-electric Figure of Merit of the films increases with increasing Si ion fluencies. In addition to the effect of quantum well confinement of the phonon transmission, the nano-scale crystal quantum dots produced by the incident Si beam further adversely affects the thermal conductivity by absorbing and dissipating phonon along the lattice, and therefore further reduces the cross plane thermal conductivity, This process increases the electron density of state therefore increasing Seebeck coefficient, and the electric conductivity.

Improved p-Type Conductivity in Heavily Al-Doped SiC by Ion-Beam-Induced Nano-Crystallization

2003 ◽  
Vol 433-436 ◽  
pp. 395-398 ◽  
Author(s):  
V. Heera ◽  
K.N. Madhusoodanan ◽  
A. Mücklich ◽  
D. Panknin ◽  
Wolfgang Skorupa
Keyword(s):  
Ion Beam ◽  
Type Conductivity ◽  
P Type
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