Download or read book High Growth Rate Deposition of Hydrogenated Microcrystalline Silicon by a High Current DC Discharge written by and published by . This book was released on 1999 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High rate growth of hydrogenated amorphous and microcrystalline silicon for thin film silicon solar cells using dynamic very high frequency plasma enhanced chemical vapor deposition written by Thomas Zimmermann and published by Forschungszentrum Jülich. This book was released on 2013 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrogenated Microcrystalline Silicon Thin Film Growth in the DC Saddle Field PECVD System written by Erik Verne Johnson and published by . This book was released on 2006 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogenated amorphous silicon (a-Si:H) and microcrystalline silicon (muc-Si:H) thin films were grown at the threshold of the amorphous-to-microcrystalline phase transition in a modified direct current (DC) saddle field plasma enhanced chemical vapour deposition (SF-PECVD) system. For the first time, the microcrystalline content of the resulting films was successfully controlled through direct manipulation of the substrate surface bias during growth. This effect was quantified for multiple pressures. The as-grown microcrystalline content and the laser-induced crystallization of the films was quantified using Raman scattering spectroscopy. The optoelectronic and morphological properties of the films were measured. These measurements included UV-Vis and IR spectroscopy, temperature-dependent four-point conductivity, photoluminescence, atomic force microscopy, and spectroscopic ellipsometry. All measurements correlated well with the microcrystalline content of the films. The growth of muc-Si:H in an ion-bombarding environment was modeled using a general formalism applicable to all methods of muc-Si:H growth. The simulation results of the model showed good qualitative agreement to experimental findings from this work as well as the literature. The operation of the SF-PECVD system using a large-area externally applied substrate bias was examined under varying conditions and new limitations to the large area application of substrate bias were discovered. Three previously unidentified plasma operation regimes were identified that explain the role of substrate bias in controlling microcrystalline growth. A methodology for the design of SF-PECVD systems for the growth of muc-Si:H was described.
Download or read book High Growth Rate Deposition of Hydrogenated Amorphous Silicon germanium Films and Devices Using ECR PECVD written by Yong Liu and published by . This book was released on 2002 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogenated amorphous silicon germanium (a-SiGe:H) films and devices have been extensively studied because of the tunable band gap for matching the solar spectrum and mature the fabrication techniques. a-SiGe:H thin film solar cells have great potential for commercial manufacture because of very low cost and adaptability to large scale manufacturing. Although it has been demonstrated that a-SiGe:H thin films and devices with good quality can be produced successfully, some issues regarding growth chemistry have remained yet unexplored, such as the hydrogen and inert gas dilution, bombardment effect, and chemical annealing, to name a few. The alloying of the SiGe introduces above an order-of-magnitude higher defect density, which degrades the performance of the a-SiGe:H thin film solar cells. This degradation becomes worse when high growth-rate deposition is required. The work presented here uses the Electron-Cyclotron-Resonance Plasma-Enhanced Chemical Vapor Deposition (ECR-PECVD) technique to fabricate a-SiGe:H films and devices with high growth rates. Helium gas, together with small amount of H2, was used as the plasma species. Thickness, optical band gap, conductivity, Urbach energy, mobility-lifetime product, and quantum efficiency were characterized during the process of pursuing good materials. High-quality material was successfully fabricated with the ECR-PECVD technique at high growth rates. The device we made with 1.47 eV band gap has a fill factor of 64.5%. With the graded band gap and graded doping techniques, 70% fill factor was achieved when the band gap was graded from 1.75 to 1.47 eV. We also got 68% fill factor with the band gap graded form 1.75 to 1.38 eV.
Download or read book Electrical Properties and Degradation Kinetics of Compensated Hydrogenated Microcrystalline Silicon Deposited by Very High frequency glow Discharge written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Growth Rate Deposition of Hydrogenated Amorphous Silicon Germanium Films and Devices Using ECR PECVD written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogenated amorphous silicon germanium films (a-SiGe:H) and devices have been extensively studied because of the tunable band gap for matching the solar spectrum and mature the fabrication techniques. a-SiGe:H thin film solar cells have great potential for commercial manufacture because of very low cost and adaptability to large-scale manufacturing. Although it has been demonstrated that a-SiGe:H thin films and devices with good quality can be produced successfully, some issues regarding growth chemistry have remained yet unexplored, such as the hydrogen and inert-gas dilution, bombardment effect, and chemical annealing, to name a few. The alloying of the SiGe introduces above an order-of-magnitude higher defect density, which degrades the performance of the a-SiGe:H thin film solar cells. This degradation becomes worse when high growth-rate deposition is required. Preferential attachment of hydrogen to silicon, clustering of Ge and Si, and columnar structure and buried dihydride radicals make the film intolerably bad. The work presented here uses the Electron-Cyclotron-Resonance Plasma-Enhanced Chemical Vapor Deposition (ECR-PECVD) technique to fabricate a-SiGe:H films and devices with high growth rates. Helium gas, together with a small amount of H[sub 2], was used as the plasma species. Thickness, optical band gap, conductivity, Urbach energy, mobility-lifetime product, I-V curve, and quantum efficiency were characterized during the process of pursuing good materials. The microstructure of the a-(Si, Ge):H material was probed by Fourier-Transform Infrared spectroscopy. They found that the advantages of using helium as the main plasma species are: (1) high growth rate--the energetic helium ions break the reactive gas more efficiently than hydrogen ions; (2) homogeneous growth--heavy helium ions impinging on the surface promote the surface mobility of the reactive radicals, so that heteroepitaxy growth as clustering of Ge and Si, columnar structure are reduced; (3) surface hydrogen removal--heavier and more energetic helium ions break the Si-H much easier than hydrogen ions. The preferential attachment of Si-H to Ge-H is reduced. They also found that with the small amount of hydrogen put into the plasma, the superior properties of a-(Si, Ge):H made from pure hydrogen dilution plasma were still maintained. These hydrogen ions help to remove the subsurface weakly bonded hydrogen and buried hydrogen. They also help to passivate the Ge-dangling bond.
Download or read book The Growth of Microcrystalline Thin Films Using ECR PECVD written by Yung Moo Huh and published by . This book was released on 2002 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: A high rate growth method of hydrogenated microcrystalline silicon, [Mu]c-Si:H, and silicon-germanium, [Mu]c-(Si, Ge):H, has been developed with very low hydrogen dilution ratio on foreign substrates, using a remote electron cyclotron resonance - plasma enhanced chemical vapor deposition (ECR-PECVD) process. In this work, the key variable was the hydrogen dilution, ratio of hydrogen to silane, [H2]/[SiH4], which ranged from 3.3 to 10, adding helium systematically. Phase transition from amorphous to microcrystalline states was observed as the amount of added helium was varied. It has been found that hydrogenated microcrystalline silicon films with more than 70 % of crystalline volume fraction were formed at high growth rates of 3.2 Å/sec at low substrate temperature below 300°C from the mixture of silane and hydrogen with a low hydrogen dilution ratio of as low as 3.3. The addition of helium did not increase the growth rate significantly, but it quickly served as disrupting microcrystalline formation. In addition, the substrate temperature-dependent phase transition was observed. The structural, electrical and optical properties, by Raman shift, x-ray diffraction, dark and photo conductivity, activation energy of dark conductivity, and photosensitivity measurements, were investigated to grow good quality [Mu]c-Si:H films at the low hydrogen dilution ratio with high growth rates. The prominent peaks at 520 cm−1 from Raman Shift spectroscopy, crystalline peaks from x-ray diffraction pattern, small photosensitivity, and low activation energy of dark conductivity due to grain boundaries in microcrystalline silicon thin films indicated the characteristic of crystalline materials.
Download or read book Growth and Characterization of Microcrystalline Silicon Films and Devices Using Very High Frequency Plasma Enhanced Chemical Vapor Deposition written by Joshua Ali Graves and published by . This book was released on 2003 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is a report of the work done to grow hydrogenated microcrystalline Si materials and p-n junction photovoltaic devices using a 45MHz (VHF) PECVD process. Several parameters such as hydrogen dilution during growth, pressure, growth temperature, and ion bombardment were systematically varied during the growth process to study their effects on crystallinity and device properties. Crystallinity of the films was studied using Raman and x-ray diffraction techniques. It was found that the typical grain size was in the range of 10-25 nm, with larger grain sizes being obtained at higher deposition temperatures. It was also found that as the deposition pressure increased, the crystalline fraction decreased. This behavior is attributed to the decrease of ion bombardment at higher pressures. Optical measurements revealed the films to have absorption characteristics similar to those of c-Si. p+/n/n+ devices were fabricated on stainless steel and semi-transparent Mo/tin oxide substrates. Capacitance spectroscopy was used to estimate total defect and dopant densities in the base layer material. Good quality devices with fill factors approaching [difference]65% and open-circuit voltages of [difference]0.45 V could be fabricated using this technique. Diffusion length of holes in this material was estimated using quantum efficiency vs. voltage techniques, and it was found to be in the range of 1.2 micrometers.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1984 with total page 1124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1988 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Growth and Characterization of Hydrogenated Amorphous Silicon Prepared Using a Combined Hot Wire and Electron Cyclotron Resonance Plasma Deposition Technique written by Matthew Alan Ring and published by . This book was released on 2003 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hot Wire Chemical Vapor Deposition (HWCVD) is an emerging technology in semiconductor materials thin film deposition due to the high growth rates and reasonable electronic properties attainable using this method. To improve the electronic characteristics of material grown by the HWCVD method, neutral ion bombardment during growth was introduced as it is shown to be beneficial in Plasma Enhanced Chemical Vapor Deposition (PECVD). Neutral ion bombardment was accomplished by using remote Electron Cyclotron Resonance (ECR) plasma and the entire deposition technique is termed ECR-HWCVD. The ECR-HWCVD films were compared to HWCVD materials deposited without ion bombardment grown at similar conditions in the same reactor using a 10.5 cm filament to substrate distance to minimize substrate heating by radiation during deposition. The growth rate is halved when ion bombardment is added to HWCVD, however it remains four times greater than the highest quality ECR-PECVD films. Also, ECR-HWCVD material exhibited better electronic properties as shown by Urbach energy, photosensitivity, hydrogen content, microstructure parameters, and space charge limited current defect measurements. In addition, the effect of substrate temperature on hydrogen content and material microstructure was investigated. Both hydrogen content and the microstructure parameter R decreased as substrate temperature increased; and when ion bombardment was added to the deposition conditions, the microstructure parameter decreased regardless of substrate temperature.
Download or read book Solar Energy Update written by and published by . This book was released on 1984 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrogenated Amorphous Silicon Grown at Low Temperature Using the Dc Saddle field Deposition System microform written by Jennifer Sue Petherick and published by Library and Archives Canada = Bibliothèque et Archives Canada. This book was released on 2004 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the dependence of amorphous silicon film properties on temperature has been carried out using the dc saddle-field glow discharge deposition method. Depositions were carried out using pure silane at substrate temperatures ranging from 50°C to 200°C. The electrical, optical and structural properties of the films were determined. The depositions were completed on a variety of substrates which were either electrically floating or held at electrical ground. Films grown under floated conditions showed an improvement in quality with increasing temperature while film quality improved at lower temperatures when grown on a grounded substrate. This result was attributed to enhanced ion bombardment occurring on the grounded substrates during growth. Application of a negative bias to the entire substrate holder was shown to enhance this effect. A low temperature solar cell was grown successfully and demonstrates the viability of low temperature photovoltaics.
Download or read book High rate Deposition of Hydrogenated Amorphous Silicon Films and Devices written by Werner Luft and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 922 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics and Technology of Amorphous Crystalline Heterostructure Silicon Solar Cells written by Wilfried G. J. H. M. van Sark and published by Springer Science & Business Media. This book was released on 2011-11-16 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: Today’s solar cell multi-GW market is dominated by crystalline silicon (c-Si) wafer technology, however new cell concepts are entering the market. One very promising solar cell design to answer these needs is the silicon hetero-junction solar cell, of which the emitter and back surface field are basically produced by a low temperature growth of ultra-thin layers of amorphous silicon. In this design, amorphous silicon (a-Si:H) constitutes both „emitter“ and „base-contact/back surface field“ on both sides of a thin crystalline silicon wafer-base (c-Si) where the electrons and holes are photogenerated; at the same time, a-Si:H passivates the c-Si surface. Recently, cell efficiencies above 23% have been demonstrated for such solar cells. In this book, the editors present an overview of the state-of-the-art in physics and technology of amorphous-crystalline heterostructure silicon solar cells. The heterojunction concept is introduced, processes and resulting properties of the materials used in the cell and their heterointerfaces are discussed and characterization techniques and simulation tools are presented.
Download or read book Plasma Processing of Semiconductors written by P.F. Williams and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma Processing of Semiconductors contains 28 contributions from 18 experts and covers plasma etching, plasma deposition, plasma-surface interactions, numerical modelling, plasma diagnostics, less conventional processing applications of plasmas, and industrial applications. Audience: Coverage ranges from introductory to state of the art, thus the book is suitable for graduate-level students seeking an introduction to the field as well as established workers wishing to broaden or update their knowledge.
