Preparation of microcrystalline silicon–carbon films

Coscia, U.; Ambrosone, G.; Lettieri, S.; Maddalena, P.; Rigato, V.; Restello, S.; Bobeico, E.; Tucci, M.

doi:10.1016/j.solmat.2004.09.015

Cited by 31 publications

(21 citation statements)

References 22 publications

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“…Alloying nc‐Si:H with oxygen 10,13,18–24 and carbon 16 is a possible way of further mitigation of the parasitic absorption loss. However, the mixing such as CO 2 44 and CH 4 45 gases during the PECVD process generally hampers the nucleation and the growth of nc‐Si:H, particularly when doped with the p ‐type dopant. This makes critical thickness even thicker, which might result in the minor improvement of solar cell efficiency.…”

Section: Resultsmentioning

confidence: 99%

Nanocrystalline‐silicon hole contact layers enabling efficiency improvement of silicon heterojunction solar cells: Impact of nanostructure evolution on solar cell performance

Umishio

Sai

Koida

et al. 2020

Progress in Photovoltaics

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Hydrogenated amorphous silicon (a‐Si:H) is a key enabler in high‐efficiency crystalline silicon solar cells known as the silicon heterojunction technology. Although efforts have been devoted to replacing doped a‐Si:H contact layer by hydrogenated nanocrystalline silicon (nc‐Si:H) to take advantage of its superior optoelectrical properties, it is still unclear whether the nc‐Si:H outperforms the a‐Si:H at the high efficiency level. Here, we show that boron‐doped (p)nc‐Si:H prepared by plasma‐enhanced chemical vapor deposition (PECVD) acts as an efficient hole contact layer, providing not only a mitigation of the parasitic absorption loss but also improvements in passivation and electrical contact properties. This results in an efficiency increase by 0.3%–0.6% absolute compared to the reference cell with the (p)a‐Si:H, and a best cell efficiency of 23.54%. We find that the critical thickness of the (p)nc‐Si:H layers required for gaining high efficiency (tc ~ 15–30 nm) is a factor of 3–6 greater than that of the (p)a‐Si:H. UV Raman spectroscopy and electrical conductivity measurements reveal that the tc of the (p)nc‐Si:H is associated with the layer growth needing for the surface coalescence of nanocrystals, determining the hole selectivity and the contact resistivity at the electrode/(p)nc‐Si:H interface. Our results suggest that such nanostructure evolution can be hastened by using a very‐high‐frequency PECVD process.

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Section: Resultsmentioning

confidence: 99%

Nanocrystalline‐silicon hole contact layers enabling efficiency improvement of silicon heterojunction solar cells: Impact of nanostructure evolution on solar cell performance

Umishio

Sai

Koida

et al. 2020

Progress in Photovoltaics

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“…It is believed that this happens due to MCD's a greater effective surface (free of binder) with free carbon atoms that can combine with silicon particles of the base material (Chen et al, 2005;Coscia et al, 2005).…”

Section: Test Results and Discussionmentioning

confidence: 99%

Machinability of Al-SiC metal matrix composites using WC, PCD and MCD inserts

2014

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SUMMARY:The aim of this work is the study of the machinability of aluminium-silicon carbide Metal Matrix Composites (MMC) in turning operations. The cutting tools used were hard metal (WC) with and without coating, different grades and geometries of Poly-Crystalline Diamond (PCD) and Mono-Crystalline Diamond (MCD). The work piece material was AMC225xe, composed of aluminium-copper alloy AA 2124 and 25% wt of SiC, being the size of the SiC particles around 3 μm. Experiments were conducted at various cutting speeds and cutting parameters in facing finishing operations, measuring the surface roughness, cutting forces and tool wear. The worn surface of the cutting tool was examined by Scanning Electron Microscope (SEM). It was observed that the Built Up Edge (BUE) and stuck material is higher in the MCD tools than in the PCD tools. The BUE acts as a protective layer against abrasive wear of the tool. RESUMEN: Maquinabilidad de composites de matriz metálica Al-SiC usando herramientas de WC, PCD y MCD.El objetivo de este trabajo es el estudio de la maquinabilidad del material compuesto de matriz metálica aluminio-carburo de silicio en operaciones de torneado. Las herramientas de corte utilizadas han sido de metal duro con y sin recubrimiento, diferentes grados de diamante policristalino (PCD) y diamante monocristalino (MCD). El material mecanizado ha sido AMC225xe, compuesto de la aleación de aluminio AA 2124 con un 25% en peso de partículas de SiC con un tamaño medio de 3 μm. Los experimentos se han realizado con diferentes velocidades de corte en una operación de refrentado, midiendo la rugosidad superficial, las fuerzas y el desgaste de la herramienta. La superficie desgastada de la herramienta ha sido examinada en el microscopio electrónico (SEM). Se ha observado que el filo recrecido y el material adherido son mayores en el caso de las herramientas de MCD que en las de PCD. El filo recrecido actúa como una capa protectora contra la abrasión.

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“…Thus, after an initial period of nucleation and incubation, a crystallite will commonly develop into a three-dimensional object with well-defined, low index crystallographic faces. It has been observed, firstly by Laudise [59], that the relationship between the velocities of ZnO crystal growth to different directions is: [10][11] > v .…”

Section: Morphological Textural and Structural Characterizationsmentioning

confidence: 99%

“…Finally, the last sample is characterized by micro flowers in which petals are hexagonal prisms, about 300-400 nm wide, and 5-6 μm long. The growth of the flower structures could be explained taking into account a possible twinning plane (80-89) that corresponds to the plane (10)(11). The (80-89) twinning plane in zincite was firstly reported in Dana's Series of Mineralogies [62].…”

Section: Morphological Textural and Structural Characterizationsmentioning

confidence: 99%

“…Metal oxides (MOX) materials are major players in the field of chemical sensing. Well-established methods, including wet chemistry [ 5 , 6 ] and different physical depositions techniques [ 7 , 8 , 9 , 10 , 11 ] are available for preparing MOX nanoparticles and nanostructured films, allowing to tailor their morphology for targeted applications in chemical sensing [ 12 , 13 , 14 , 15 ].…”

Section: Introductionmentioning

confidence: 99%

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Growth Mechanisms of ZnO Micro-Nanomorphologies and Their Role in Enhancing Gas Sensing Properties

Fioravanti

Marani

Morandi

et al. 2021

Sensors

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Zinc oxide (ZnO) is one of the main functional materials used to realize chemiresistive gas sensors. In addition, ZnO can be grown through many different methods obtaining the widest family of unique morphologies. However, the relationship between the ZnO morphologies and their gas sensing properties needs more detailed investigations, also with the aim to improve the sensor performances. In this work, seven nanoforms (such as leaves, bisphenoids, flowers, needles, etc.) were prepared through simple wet chemical synthesis. Morphological and structural characterizations were performed to figure out their growth mechanisms. Then, the obtained powders were deposited through screen-printing technique to realize thick film gas sensors. The gas sensing behavior was tested toward some traditional target gases and some volatile organic compounds (acetone, acetaldehyde, etc.) and compared with ZnO morphologies. Results showed a direct correlation between the sensors responses and the powders features (morphology and size), which depend on the specific synthesis process. The sensors can be divided in two behavioral classes, following the two main morphology kinds: aggregates of nanocrystals (leaves and bisphenoids), exhibiting best performances versus all tested gases and monocrystal based (stars, needle, long needles, flowers, and prisms).

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Preparation of microcrystalline silicon–carbon films

Cited by 31 publications

References 22 publications

Nanocrystalline‐silicon hole contact layers enabling efficiency improvement of silicon heterojunction solar cells: Impact of nanostructure evolution on solar cell performance

Nanocrystalline‐silicon hole contact layers enabling efficiency improvement of silicon heterojunction solar cells: Impact of nanostructure evolution on solar cell performance

Machinability of Al-SiC metal matrix composites using WC, PCD and MCD inserts

Growth Mechanisms of ZnO Micro-Nanomorphologies and Their Role in Enhancing Gas Sensing Properties

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