High-Quality a-Si-Based Alloys : a-SiGe Films Fabricated in a Super Chamber and Superlattice Structure a-Si Films Prepared by a Photo-CVD Method

1987 ◽  
Vol 95 ◽  
Author(s):  
Shinya Tsuda ◽  
Hisao Haku ◽  
Hisaki Tarui ◽  
Takao Matsuyama ◽  
Katsunobu Sayama ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Photovoltaic Effect ◽  
High Vacuum ◽  
Reaction Chamber ◽  
Wide Bandgap ◽  
Ultra High Vacuum ◽  
High Quality ◽  
Cvd Method ◽  
Superlattice Structure ◽  
Si Films

AbstractIn order to improve the conversion efficiency of a-Si solar cells, high-quality a-Si based alloys of both narrow handgap and wide bandgap were studied.Concerning the narrow bandgap material, we found a particular dependence of film qualities on substrate temperature. In addition, high-quality a-SiGe:H films were obtained by using a super chamber (separated ultra-high vacuum reaction chamber).As for the high-quality wide bandgap material, a-Si/a-SiC superlattice structure films fabricated by a photo-CVD method were studied for the first time. From the analysis of their properties, we found that the superlattice structure p-layer was an active layer for photovoltaic effect. A conversion efficiency of 11.2% has been obtained for a pin a-Si solar cell whose player was of the superlattice structure.

High Quality a-Si Films and Superlattice Structure p-Layer a-Si Solar Cells

1986 ◽  
Vol 70 ◽  
Author(s):  
Shoichi Nakano ◽  
Shinya Tsuda ◽  
Hisaki Tarui ◽  
Tsuyoshi Takahama ◽  
Hisao Haku ◽  
...  
Keyword(s):  
Solar Cells ◽  
Conversion Efficiency ◽  
Reaction Chamber ◽  
High Quality ◽  
Cvd Method ◽  
Superlattice Structure ◽  
Si Solar Cells ◽  
New Material ◽  
Si Films ◽  
First Time

ABSTRACTAs a new preparation method for high-quality a-Si films, we have developed the super chamber, a separated UHV reaction chamber system. A low impurity concentration and excellent film properties were obtained by the super chamber. A conversion efficiency of 11.7% was obtained for an a-Si solar cell using a high-quality i-layer deposited by the super chamber, and a p-layer fabricated by a photo-CVD method.As a new material, amorphous superlattice structure films were fabricated by the photo-CVD method for the first time. Quantization effects and low damage to the interfaces were observed. Superlattice structure p-layer a-Si solar cells were fabricated for the first time, and a conversion efficiency of 10.5% was obtained.

Preparation and Properties of High-Quality a-Si Films with a Super Chamber : Separated Ultra-High Vacuum Reaction Chamber

1987 ◽  
Vol 26 (Part 1, No. 1) ◽  
pp. 33-38 ◽  
Author(s):  
Shinya Tsuda ◽  
Tsuyoshi Takahama ◽  
Masao Isomura ◽  
Hisaki Tarui ◽  
Yukio Nakashima ◽  
...  
Keyword(s):  
High Vacuum ◽  
Reaction Chamber ◽  
Ultra High Vacuum ◽  
High Quality ◽  
Si Films

High Performance A–Si Solar Cells and Narrow Bandgap Materials

1985 ◽  
Vol 49 ◽  
Author(s):  
Shoichi Nakano ◽  
Yasuo Kishi ◽  
Michitoshi Ohnishi ◽  
Shinya Tsuda ◽  
Hisashi Shibuya ◽  
...  
Keyword(s):  
Solar Cells ◽  
Conversion Efficiency ◽  
High Performance ◽  
Reaction Chamber ◽  
Interface Properties ◽  
High Quality ◽  
Cvd Method ◽  
Si Solar Cells ◽  
Narrow Bandgap ◽  
First Time

AbstractHigh performance a-Si solar cells were developed. A conversion efficiency of 11.5% was achieved for a textured TCO/p-SiC/in/Ag structure with a size of 1 cm2 using the high quality i-layer fabricated by a new consecutive, separated reaction chamber apparatus. A conversion efficiency of 9.0% was obtained with a size of 10cm × 10cm. A high quality a-SiGe:H:F, which is a new narrow bandgap material for a-Si solar cells, was fabricated by a glow discharge decomposition of SiF4 + GeF4 + H2.A photo-CVD method was investigated in order to improve the interface properties of a–Si solar cells. A conversion efficiency of 11.0% was obtained with a solar cell in which the p-layer is fabricated by the photo-CVD method. a-SiGe:H films were fabricated by the photo-CVD method for the first time as a narrow bandgap material for multi-bandgap a-Si solar cells.

Growth and Characterization of High Quality Si 1- x-y Ge x C y Alloy Grown by Ultra-High Vacuum Chemical Vapor Deposition

1999 ◽  
Vol 16 (10) ◽  
pp. 750-752 ◽  
Author(s):  
Zhen Qi ◽  
Jing-yun Huang ◽  
Zhi-zhen Ye ◽  
Huan-ming Lu ◽  
Wei-hua Chen ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Ultra High Vacuum ◽  
High Quality

Deposition of a-Si:H Devices in a RTR System for Photovoltaic and Macroelectronic Applications

1999 ◽  
Vol 557 ◽  
Author(s):  
M. Scholz ◽  
D. Peros ◽  
M. Böhm
Keyword(s):  
High Vacuum ◽  
Chemical Vapor ◽  
Transparent Conductive Oxide ◽  
Rf Magnetron Sputtering ◽  
Film Deposition ◽  
Ultra High Vacuum ◽  
Molecular Flow ◽  
Metal Contacts ◽  
High Quality ◽  
First Results

AbstractThis work presents first results of potential manufacturing processes for integrated series connected hydrogenated amorphous silicon (a-Si:H) thin film solar modules and/or pindiode/TFT based macroelectronic circuits on flexible tapes. A RTR (Reel-To-Reel) deposition system on laboratory scale has been built, The system consists of seven metal sealed LIHV stinless steel chambers to obtain ultra high vacuum as a basis for high quality a-Si:H layers, in order to support continuous movement of the tape in the RTR process the chambers cannot be isolated from each other. The necessary pressure difference between the sputtering chambers and the PECVD (Plasma Enhanced Chemical Vapor Deposition) chambers is provided by pressure stages. They are optimized for high molecular flow resistance without any influence on the moving substrate tape. The back metal contacts and the semitransparent TCO (Transparent Conductive Oxide) contacts are deposited by rf magnetron sputtering, the a-Si:H film system is deposited by PECVD. Parallel to the film deposition a Nd:YAG laser patterning system is coupled into one chamber. This allows for instance a total manufacturing of integrated series connected solar modules in one system without breaking the vacuum. Our present investigations focus on the deposition of doped and intrinsic high quality a-Si:H based layers in neighboring chambers. The quality of semiconducting films deposited in adjacent chambers is studied with regard to potential contamination effects.

Preparation and Properties of a-SiGe:H Films Fabricated with a Super Chamber (Separated Ultra-High Vacuum Reaction Chamber)

1987 ◽  
Vol 26 (Part 1, No. 12) ◽  
pp. 1978-1982 ◽  
Author(s):  
Hisao Haku ◽  
Katsunobu Sayama ◽  
Yukio Nakashima ◽  
Tsuyoshi Takahama ◽  
Masao Isomura ◽  
...  
Keyword(s):  
High Vacuum ◽  
Reaction Chamber ◽  
Ultra High Vacuum

Thermal Conductivity of Si/SiGe Superlattice Film

2008 ◽  
Author(s):  
Chun-Kai Liu ◽  
Heng-Chieh Chien ◽  
Ming-Ji Dai ◽  
Chih-Kuang Yu ◽  
Chun-Yeh Hsu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Theoretical Analysis ◽  
High Vacuum ◽  
Experimental Studies ◽  
Chemical Vapor ◽  
Ultra High Vacuum ◽  
Interfacial Thermal Resistance ◽  
Boltzmann Transport ◽  
Superlattice Structure ◽  
Acoustic Mismatch

It has been proposed that the use of superlattice structure is effective for reduction of lattice thermal conductivity in the direction perpendicular to superlattice interfaces which can lead to improvement of figure of merit. In this work, we have evaluated the thermal conductivity of Si/SiGe superlattice structure films by theoretical analysis and experimental studies. In experiments, the ultra-high vacuum chemical vapor deposition (UHVCVD) has been employed to formation the Si/Si0.71Ge0.29 superlattice film. The cross-plane thermal conductivity of a Si/Si0.71Ge0.29 superlattice is measured based on the 3 ω method. In theoretical analysis, we use the Boltzmann transport equation to analyze the phenon transport in superlattice film. We compared the thermal conductivities of several Si/Si0.71Ge0.29 superlattice structure films by changing the thickness of Si and Si0.71Ge0.29. The results indicate that increasing the period (one layer Si and one layer Si0.71Ge0.29) length will lead to increase acoustic mismatch between the adjacent layers, and hence increased interfacial thermal resistance. However, if the total thickness of the superlattice film is fixed, reducing the period length will lead to decreased effective thermal conductivity due to the increased number of interfaces.

High-Quality A-Si Films Prepared by the Direct Photo-Cvd Method

1989 ◽  
Vol 149 ◽  
Author(s):  
S. Nakano ◽  
K. Wakisaka ◽  
M. Kameda ◽  
M. Isomura ◽  
T. Matsuyama ◽  
...  
Keyword(s):  
High Efficiency ◽  
Defect States ◽  
Low Light ◽  
High Quality ◽  
Characteristic Energy ◽  
Area Efficiency ◽  
Cvd Method ◽  
Si Solar Cell ◽  
Si Films

ABSTRACTA high-efficiency integrated-type a-Si solar cell submodule with a size of 10cm × 10cm has been fabricated and a total area efficiency of 9.6% is obtained by using a high-quality p-layer doped with B(CH3)3 We have developed an advanced direct photo-CVD method. High-quallt” a-SI films with low tail characteristic energy and low light-induced degradation is prepared by this method. We have also studied the role of Si-H2 bonds on the light-induced effect. The result implies that Si-H bonds stabilize the defect states, resulting in a large light-induced degradation.

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

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.

Preparation of High-Quality poly-Si and μc-Si Films by the SPC Method

1989 ◽  
Vol 164 ◽  
Author(s):  
T. Matsuyama ◽  
M. Nishikuni ◽  
M. Kameda ◽  
S. Okamoto ◽  
M. Tanaka ◽  
...  
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
Solid Phase ◽  
Wavelength Region ◽  
Optical Transmittance ◽  
High Quality ◽  
Long Wavelength ◽  
Si Solar Cell ◽  
Si Films ◽  
P Type

AbstractWe have achieved the highest total area conversion efficiency for an integrated type 10cm × 10cm a-Si solar cell at 10.2%. This value is the world record for a 10cm × 10cm a-Si solar cell. For further improvement of conversion efficiency in a-Si solar cells, it is necessary to develop materials with high-photosensitivity in the long wavelength region and materials with high conductivity. We have developed a Solid Phase Crystallization (SPC) method of growing a Si crystal at temperatures as low as 600°C. Using this method, thin-film polycrystalline silicon (poly-Si) with higP-photosensitivity in the long wavelength region and Hall mobility of 70cm2/V sec was obtained and quantum efficiency in the range of 800,∼ lO00nm was achieved up to 80% in the n-type poly-Si with grain size of about 2μm. We also succeeded in preparing a device-quality p-type microcrystalline silicon (μc-Si) using the SPC method at 620°C for 3 hours from the conventional plasma-CVD p-type amorphous silicon (a-5i) withoul using any post-doping process. Obtained properties of μd=2 × 103 (.cm) and a high optical transmittance in the 2.0 ∼ 3.0 eV range are better as a window material than the conventional p-type μc-Si:H. Therefore, it was concluded that the SPC method is better as a new technique to prepare high-quality solar cell materials.

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