Advances in Amorphous Silicon Integrated Photonics Science and Technology

2005 ◽  
Vol 862 ◽  
Author(s):  
G.P. Halada ◽  
Samrat Chawda ◽  
J. Mawyin ◽  
R.J. Tonucci ◽  
A.H. Mahan ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Amorphous Silicon ◽  
Femtosecond Laser Ablation ◽  
Silicon Powder ◽  
Scientific Basis ◽  
Film Structure ◽  
Integrated Photonics ◽  
The Past ◽  
Silicon Based ◽  
Deposited Films

AbstractOver the past few years we have been developing a scientific basis for amorphous silicon-based integrated photonics technology. Waveguides using hydrogen-implanted, optically-smooth, hot-wire-deposited films have been prepared and demonstrated, and structures were characterized by Raman spectroscopy of the implanted and the non-implanted regions of the waveguide samples. The analysis is consistent with greater disorder in the film structure induced through implantation. More recently, materials prepared by femtosecond laser ablation of silicon powder have been characterized by Raman spectroscopy indicating a structure having both amorphous and crystalline components. As amorphous silicon photonics continues to evolve, the patterning of materials of differing crystallinity may become an issue of interest.

Hydrogen Stability in Hydrogenated Amorphous Silicon-Based Alloys

1991 ◽  
Vol 219 ◽  
Author(s):  
W. Beyer ◽  
J. Herion ◽  
H. Wagner ◽  
U. Zastrow
Keyword(s):  
Amorphous Silicon ◽  
Hydrogen Diffusion ◽  
Film Structure ◽  
Desorption Energy ◽  
Germanium Content ◽  
Surface Desorption ◽  
Silicon Based ◽  
Hydrogenated Amorphous ◽  
Thermal Stability Of ◽  
Hydrogen Effusion

ABSTRACTThe thermal stability of hydrogen in amorphous silicon-based alloy films was studied by deuterium/hydrogen interdiffusion and hydrogen effusion experiments. Depending on the film structure, hydrogen stability is limited by hydrogen surface desorption or hydrogen diffusion. The hydrogen surface desorption energy is found to decrease with rising germanium content and to increase with rising nitrogen and carbon content. At T = 400°C, hydrogen diffusion is found to proceed in the germanium subnetwork for a-SiGe alloys and in the silicon subnetwork for a-SiN and a-SiC alloys.

scholarly journals Microstructure Changes of Ti-Al-C Films Deposited by Filtered Cathodic Vacuum Arc

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Xianjuan Pang ◽  
Xiaoqiang Liu ◽  
Bo Jin
Keyword(s):  
Raman Spectroscopy ◽  
Ir Spectroscopy ◽  
Flow Rate ◽  
Film Structure ◽  
Vacuum Arc ◽  
Chemical Bonds ◽  
Hydrogen Atoms ◽  
Filtered Cathodic Vacuum Arc ◽  
Carbon Network ◽  
Deposited Films

Nanocomposite Ti-Al-C films were deposited by filtered cathodic vacuum arc (FCVA) at different CH4flows. The deposited films were characterized in terms of elemental and phase compositions, chemical bonds, and texture as a function of CH4flow rate by XRD, XPS, HRTEM, Raman spectroscopy, and IR spectroscopy. The results show that the TiC grain size decreases from 4.2 to 2.9 nm as the CH4flow rate increases from 30 to 80 sccm. The analysis of XPS, HRTEM, and Raman spectroscopy shows that the microstructure of deposited films turns from a TiC dominant TiC-C film to a carbon network dominant TiAl-doped a-C film structure as the CH4flow increases from 30 sccm to 80 sccm. IR spectroscopy shows that most of the hydrogen atoms in the deposited films are bonded to the sp3-hybridized C atoms. All the composition and microstructure change can be explained by considering the plasma conditions and the effect of CH4flow.

Photoconductivity in Vacuum Deposited Films of Silicon-Based Polymers

1996 ◽  
Vol 444 ◽  
Author(s):  
H. Okumoto ◽  
M. Shimomura ◽  
N. Minami ◽  
Y. Tanabe
Keyword(s):  
Charge Transfer ◽  
Chemical Modification ◽  
Electronic Transport ◽  
Hole Transport ◽  
Electron Acceptors ◽  
Oxygen Atmosphere ◽  
Dangling Bonds ◽  
Silicon Based ◽  
Deposited Films

AbstractSilicon-based polymers with σconjugated electrons have specific properties; photoreactivity for microlithography and photoconductivity for hole transport materials. To explore the possibility of combining these two properties to develop photoresists with electronic transport capability, photoconductivity of polysilanes is investigated in connection with their photoinduced chemical modification. Increase in photocurrent is observed accompanying photoreaction of poly(dimethylsilane) vacuum deposited films. This increase is found to be greatly enhanced in oxygen atmosphere. Such changes of photocurrent can be explained by charge transfer to electron acceptors from Si dangling bonds postulated to be formed during photoreaction.

Use of Transparent Conductive Oxide Materials with Low Indices of Refraction in Amorphous Silicon-Based Solar Cell Technology

2005 ◽  
Vol 862 ◽  
Author(s):  
Scott J. Jones ◽  
Joachim Doehler ◽  
Tongyu Liu ◽  
David Tsu ◽  
Jeff Steele ◽  
...  
Keyword(s):  
Solar Cell ◽  
Amorphous Silicon ◽  
Transparent Conductive Oxide ◽  
Open Circuit ◽  
Long Term Stability ◽  
Back Reflectors ◽  
Stability Issues ◽  
Silicon Based ◽  
Solar Cell Technology

AbstractNew types of transparent conductive oxides with low indices of refraction have been developed for use in optical stacks for the amorphous silicon (a-Si) solar cell and other thin film applications. The alloys are ZnO based with Si and MgF added to reduce the index of the materials through the creation of SiO2 or MgF2, with n=1.3-1.4, or the addition of voids in the materials. Alloys with 12-14% Si or Mg have indices of refraction at λ=800nm between 1.6 and 1.7. These materials are presently being used in optical stacks to enhance light scattering by Al/multi-layer/ZnO back reflectors in a-Si based solar cells to increase light absorption in the semiconductor layers and increase open circuit currents and boost device efficiencies. In contrast to Ag/ZnO back reflectors which have long term stability issues due to electromigration of Ag, these Al based back reflectors should be stable and usable in manufactured PV products. In this manuscript, structural properties for the materials will be reported as well as the performance of solar cell devices made using these new types of materials.

Low Power Pixel-Level ADC Readout Circuit for an Amorphous Silicon-Based Microbolometer

2009 ◽  
Vol E92-C (5) ◽  
pp. 708-712
Author(s):  
Dong-Heon HA ◽  
Chi Ho HWANG ◽  
Yong Soo LEE ◽  
Hee Chul LEE
Keyword(s):  
Low Power ◽  
Amorphous Silicon ◽  
Readout Circuit ◽  
Silicon Based

High switching uniformity and 50 fJ/bit energy consumption achieved in amorphous silicon-based memristive device with an AgInSbTe buffer layer

2021 ◽  
Vol 118 (26) ◽  
pp. 263507
Author(s):  
Yanyun Ren ◽  
Xiaojing Fu ◽  
Zhi Yang ◽  
Ruoyao Sun ◽  
Ya Lin ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Amorphous Silicon ◽  
Buffer Layer ◽  
Memristive Device ◽  
Silicon Based

Calibration Methods to Circumvent Unknown Component Spectra for Quantitative in situ Raman Monitoring of Co-Polymerisation Reaction

2021 ◽  
Author(s):  
Wendy Rusli ◽  
Pavan Kumar Naraharisetti ◽  
Wee Chew
Keyword(s):  
Raman Spectroscopy ◽  
Reaction Monitoring ◽  
The Past ◽  
In Situ Raman ◽  
Calibration Methods ◽  
Unknown Component

The use of Raman spectroscopy for reaction monitoring has been successfully applied over the past few decades. One complication in such usage is the applicability for quantitative reaction studies. This...

Performance Assessment Study of Indian Railways – Case of Low Efficiencies in Large Government Monopoly

2021 ◽  
pp. 036119812110255
Author(s):  
Sabyasachi S. Roy ◽  
Mukul Kulshrestha
Keyword(s):  
Scientific Basis ◽  
Data Envelopment ◽  
Policy Reforms ◽  
Management Planning ◽  
Rail Network ◽  
The Past ◽  
Assessment Study ◽  
Micro Level ◽  
Global Population ◽  
Financial Losses

Indian Railways is the world’s largest government-owned monopoly, annually carrying passenger numbers that surpass the global population. It is world’s fourth largest rail network after the U.S.A., China, and Russia, and is managed by a separate Ministry of Railways. The operating ratios have consistently been around 90% in the past several years, indicating that that the capability to generate operational surplus is low. Further, its expenditure on staff and their pensions has been increasing. Consequently, capacity growth is increasingly being funded through borrowings, which threatens to further worsen the financial situation. Thus, railway services in India are often perceived as being inefficient and unsatisfactory. However, this perception of inefficient services has no scientific basis as mid- and micro-level efficiency analyses of Indian Railways have never been carried out. This paper adopts a data envelopment analysis (DEA)-based approach to evaluate the performance efficiencies of the 69 divisions of Indian Railways. Six models that deploy a range of performance indicators like operating expenditures, numbers of staff employed or passengers carried, freight carried, rail network length, and revenues generated have been employed to assess efficiencies. The results demonstrate the existence of significant inefficiencies that may possibly be attributed to lack of proper management, planning policies, and mis-governance, resulting in significant financial losses. The paper discusses these issues and the policy reforms needed in the developing country context, while suggesting some reforms that may lead to improved sector performances.

A recent overview on the porphyrin-based π-extended small molecules as donors and acceptors for high-performance organic solar cells

2021 ◽  
Author(s):  
Venkatesh Piradi ◽  
Feng Yan ◽  
Xunjin Zhu ◽  
Wai-Yeung Raymond Wong
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Small Molecules ◽  
Organic Solar Cells ◽  
High Performance ◽  
Cost Effective ◽  
Effective Alternative ◽  
The Past ◽  
Cost Effective Alternative ◽  
Silicon Based

Organic solar cells (OSCs) have been considered as a promising cost-effective alternative to silicon-based solar cell counterparts due to their lightweight, mechanical flexibility, and easy fabrication features. Over the past...

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