Amorphous Silicon Selenium Alloy Film Deposited Under Hydrogen Dilution

1991 ◽  
Vol 219 ◽  
Author(s):  
Muzhi He ◽  
Guang H. Lin ◽  
J. O'M. Bockris
Keyword(s):  
Amorphous Silicon ◽  
Chemical Vapor ◽  
Selenium Concentration ◽  
Alloy Film ◽  
Dark Conductivity ◽  
Flow Rate Ratio ◽  
Selenium Atom ◽  
Alloy Films ◽  
Hydrogen Dilution ◽  
Photo Response

ABSTRACTAmorphous silicon selenium alloy films were prepared by plasma enhanced chemical vapor deposition with hydrogen dilution. The flow rate ratio of hydrogen to silane was about 8:1. Amorphous silicon selenium alloy was found to have an optical bandgap ranging from 1.7 eV to 2.0 eV depending on the selenium concentration in the films. The light to dark conductivity ratios of the alloy films are ∼ 104. The optical and electrical properties, Urbach tail energy and sub-bandgap photo response spectroscopy of the alloy film were investigated. The film quality of the alloy deposited with hydrogen dilution is greatly improved comparing to that of the alloy film deposited without hydrogen dilution. The electron spin resonance experiment shows that selenium atom is a good dangling bond terminator.

Influence of Hydrogen Dilution on Electrical Properties of Amorphous Silicon Thin Films Deposited on Glass Substrates

2011 ◽  
Vol 221 ◽  
pp. 117-122
Author(s):  
Ying Ge Li ◽  
Dong Xing Du
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Properties ◽  
Amorphous Silicon ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Thin Layers ◽  
Glass Substrates ◽  
Silicon Thin Films ◽  
Hydrogen Dilution

Thin film Amorphous Silicon materials have found wide application in photovoltaic industry. In this paper, thin layers (around 300nm) of intrinsic hydrogenated amorphous silicon (a-Si:H) are fabricated on glass (Corning Eagle2000TM) substrates by employing plasma enhanced chemical vapor deposition (PECVD) system with gas sources of silane and hydrogen. The deposited thin films are proven to be material of amorphous silicon by Raman spectroscopy measurement and their electronic transport properties are thoroughly characterized in terms of photoconductivity, dark conductivity and photo response. The effect of Hydrogen dilution on electrical properties are investigated for a-Si:H thin films deposited in the temperatures range of 150~200°C. Results indicate that a-Si:H thin films on glass substrate owns device-quality electrical properties and could be applied on fabricating thin film solar cells as the absorber layer material and on other photovoltaic or photo electronic devices.

High Rate Deposition of Stable Hydrogenated Amorphous Silicon in Transition from Amorphous to Microcrystalline Silicon

2003 ◽  
Vol 762 ◽  
Author(s):  
Guofu Hou ◽  
Xinhua Geng ◽  
Xiaodan Zhang ◽  
Ying Zhao ◽  
Junming Xue ◽  
...  
Keyword(s):  
Phase Transition ◽  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
High Rate ◽  
Very High Frequency ◽  
High Quality ◽  
Working Pressure ◽  
Hydrogen Dilution ◽  
Hydrogenated Amorphous

AbstractHigh rate deposition of high quality and stable hydrogenated amorphous silicon (a-Si:H) films were performed near the threshold of amorphous to microcrystalline phase transition using a very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) method. The effect of hydrogen dilution on optic-electronic and structural properties of these films was investigated by Fourier-transform infrared (FTIR) spectroscopy, Raman scattering and constant photocurrent method (CPM). Experiment showed that although the phase transition was much influenced by hydrogen dilution, it also strongly depended on substrate temperature, working pressure and plasma power. With optimized condition high quality and high stable a-Si:H films, which exhibit σph/σd of 4.4×106 and deposition rate of 28.8Å/s, have been obtained.

Intrinsic and Doped m c-Si:H TFT Layers using 13.56 MHz PECVD at 250°C

2004 ◽  
Vol 808 ◽  
Author(s):  
Czang-Ho Lee ◽  
Denis Striakhilev ◽  
Arokia Nathan
Keyword(s):  
Performance Improvement ◽  
Volume Fraction ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Rf Power ◽  
Crystalline Volume Fraction ◽  
Microcrystalline Silicon ◽  
Bias Stress ◽  
Hydrogen Dilution ◽  
Low Threshold

ABSTRACTUndoped and n+ hydrogenated microcrystalline silicon (μc-Si:H) films for thin film transistors (TFTs) were deposited at a temperature of 250°C with 99 ∼ 99.6 % hydrogen dilution of silane by standard 13.56 MHz plasma enhanced chemical vapor deposition (PECVD). High crystallinity m c-Si:H films were achieved at 99.6 % hydrogen dilution and at low rf power. An undoped 80 nm thick m c-Si:H film showed a dark conductivity of the order of 10−7 S/cm, the photosensitivity of an order of 102, and a crystalline volume fraction of 80 %. However, a 60 nm thick n+ μc-Si:H film deposited using a seed layer showed a high dark conductivity of 35 S/cm and a crystalline volume fraction of 60 %. Using n+ μc-Si:H films as drain and source contact layers in a-Si:H TFTs provides substantial performance improvement over n+ a-Si:H contacts. Finally, fully μ c-Si:H TFTs incorporating intrinsic m c-Si:H films as channel layers and n+ μc-Si:H films as contact layers have been fabricated and characterized. These TFTs exhibit a low threshold voltage and a field effect mobility of 0.85 cm2/Vs, and are far more stable under gate bias stress than a-Si:H TFTs.

scholarly journals Structure and Optical Properties of Co-Sputtered Amorphous Silicon Tin Alloy Films for NIR-II Region Sensor

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4076
Author(s):  
Xiang-Dong Jiang ◽  
Ming-Cheng Li ◽  
Rui-Kang Guo ◽  
Ji-Min Wang
Keyword(s):  
Amorphous Silicon ◽  
Deposition Temperature ◽  
Near Infrared ◽  
Dark Conductivity ◽  
Linear Variation ◽  
Sensitive Layer ◽  
Tem Analysis ◽  
Alloy Films ◽  
Non Invasive ◽  
Xrd And Tem

Near-infrared brain imaging technology has great potential as a non-invasive, real-time inspection technique. Silicon-tin (SiSn) alloy films could be a promising material for near-infrared brain detectors. This study mainly reports on the structure of amorphous silicon tin alloy thin films by Raman spectroscopy to investigate the influence of doped-Sn on an a-Si network. The variations in TO peak caused by the increase in Sn concentration indicate a decrease in the short-range order of the a-Si network. A model has been proposed to successfully explain the non-linear variation in Raman parameters of ITA/ITO and ILA+LO/ITO. The variations of Raman parameters of the films with a higher deposition temperature indicate the presence of SiSn nanocrystals, though the SiSn nanocrystals present no Raman peaks in Raman spectra. XRD and TEM analysis further illustrate the existence of nanocrystals. The ratio of photo/dark conductivity and optical bandgap results demonstrate that the films can be selected as a sensitive layer material for NIR-II region sensors.

Deposition of High Quality Amorphous Silicon by a New “Hot Wire” CVD Technique

1999 ◽  
Vol 557 ◽  
Author(s):  
Scott Morrison ◽  
Ken Coates ◽  
Jianping Xi ◽  
Arun Madan
Keyword(s):  
Amorphous Silicon ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Hot Wire ◽  
Large Area ◽  
New Approach ◽  
Vapor Deposition Technique ◽  
Photovoltaic Applications ◽  
Technical Issues ◽  
Silicon Materials

AbstractFor the “Hot Wire” chemical vapor deposition technique (HWCVD) method to be applicable for photovoltaic applications, certain critical technical issues need to be addressed and resolved such as: lifetime of the filaments, reproducibility, large area demonstration of the material and stable devices. We have developed a new approach (patent applied for) which addresses some of these problems, specifically longevity of the filaments and reproducibility of the materials produced. The new filament material used has so far shown no appreciable degradation even after deposition of >200 μm of amorphous silicon (a-Si). We report that this can produce “state-ofthe-art” a-Si with a dark conductivity of <10-10 (Ohm*cm)-1 and photoconductivity of >10-5 (Ohm*cm)-1 this material can also be doped p- or n-type. We also provide data using XRD as well as the Raman spectra. These materials have been incorporated into simple Schottky barrier structures. The development of microcrystalline silicon materials is also discussed.

Sign in / Sign up

Export Citation Format

Share Document