A ceramic fuel cell in an all solid-state energy conversion device that produces electricity by electrochemically combining fuel and oxidant gases across an ionic conducting oxide. Current ceramic fuel cells use an oxygen-ion conductor or a proton conductor as the electrolyte and operate at high temperatures (>600°C). Ceramic fuel cells, commonly referred to as solid-oxide fuel cells (SOFCs), are presently under development for a variety of power generation applications. This paper reviews the science and technology of ceramic fuel cells and discusses the critical issues posed by the development of this type of fuel cell. The emphasis is given to the discussion of component materials (especially, ZrO2 electrolyte, nickel/ZrO2 cermet anode, LaMnO3 cathode, and LaCrO3 interconnect), gas reactions at the electrodes, stack designs, and processing techniques used in the fabrication of required ceramic structures.

Ceramic Fuel Cells

Recent worldwide interest in building a decentralized, hydrogen-based energy economy has refocused attention on the solid oxide fuel cell (SOFC) as a potential source of efficient, environmentally friendly, fuel-versatile electric power. Due to its high operating temperature, the SOFC offers several potential advantages over polymer-based fuel cells, including reversible electrode reactions, low internal resistance, high tolerance to typical catalyst poisons, production of high-quality waste heat for (among other uses) reformation of hydrocarbon fuels, as well as the possibility of burning hydrocarbon fuels directly. Today, SOFCs are much closer to commercial reality than they were 20 years ago, due largely to technological advances in electrode material composition, microstructure control, thin-film ceramic fabrication, and stack and system design. These advances have led to dozens of active SOFC development programs in both stationary and mobile power and contributed to commercialization or development in a number of related technologies, including gas sensors,1 solid-state electrolysis devices,2 and iontransport membranes for gas separation and partial oxidation.3 Many reviews are available which summarize the technological advances made in SOFCs over the last 15-35 yearssreaders who are primarily interested in knowing the state-of-the art in materials, design, and fabrication (including the electrodes) are encouraged to consult these reviews.4-12 This review focuses on the factors governing SOFC cathode performancesadvances we have made over † Dedicated to Brian Steele, 1929-2003. Researcher, Entrepreneur, Consensus Seeker. 4791 Chem. Rev. 2004, 104, 4791−4843

Factors Governing Oxygen Reduction in Solid Oxide Fuel Cell Cathodes

Despite being first demonstrated over 160 years ago, and offering significant environmental benefits and high electrical efficiency, it is only in the last two decades that fuel cells have offered a realistic prospect of being commercially viable. The solid oxide fuel cell (SOFC) offers great promise and is presently the subject of intense research activity. Unlike other fuel cells the SOFC is a solid-state device which operates at elevated temperatures. This review discusses the particular issues facing the development of a high temperature solid-state fuel cell and the inorganic materials currently used and under investigation for such cells, together with the problems associated with operating SOFCs on practical hydrocarbon fuels.

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Solid oxide fuel cells

Progress in material selection for solid oxide fuel cell technology: A review

A zinc oxide (ZnO) field effect transistor exhibits large input amplitude by using a gate insulating layer. A channel layer and the gate insulating layer are sequentially laminated on a substrate. A gate electrode is formed on the gate insulating layer. A source contact and a drain contact are disposed at the both sides of the gate contact and are electrically connected to the channel layer via openings. The channel layer is formed from n-type ZnO. The gate insulating layer is made from aluminum nitride/aluminum gallium nitride (AlN/AlGaN) or magnesium zinc oxide (MgZnO), which exhibits excellent insulation characteristics, thus increasing the Schottky barrier and achieving large input amplitude. If the FET is operated in the enhancement mode, it is operable in a manner similar to a silicon metal oxide semiconductor field effect transistor (Si-MOS-type FET), resulting in the formation of an inversion layer.

High-electron mobility transistor with zinc oxide

The conductivity and Seebeck coefficient of the perovskite-type oxides La 1−x Sr x CoO 3− δ (x=0-0.7) were measured in 10 −5 -1 atm O 2 gas at temperatures 25 o -1000 o C. The results are discussed in relation to the lattice-parameter and oxygen nonstoichiometry

https://iopscience.iop.org/article/10.1149/1.2097187/pdf

Electrical Conductivity and Seebeck Coefficient of Nonstoichiometric La1 − x Sr x CoO3 − δ

We report the observation of self‐limited layer‐by‐layer etching of Si by alternated chlorine adsorption and low energy Ar+ ion irradiation using an ultraclean electron‐cyclotron‐resonance plasma apparatus. The etch rate per cycle increased with the chlorine supplying time and saturated to a constant value of about 1/2 atomic layer per cycle for Si(100) and 1/3 for Si(111), which was independent of the chlorine partial pressure in the range of 1.3–6.7 mPa. These results indicate that etching was determined by self‐limited adsorption of chlorine. Moreover, the chlorine adsorption rate was found to be described by a Langmuir‐type equation with an adsorption rate constant k=83 and 110 (Pa s)−1 for Si(100) and Si(111), respectively.

Self‐limited layer‐by‐layer etching of Si by alternated chlorine adsorption and Ar+ ion irradiation

There is provided a novel bonded semiconductor wafer having a layered structure alternately stacked with semiconductor layers and insulator layers in two cycles or more and manufactured by means of a bonding process, wherein at least one of the insulator layers is formed with ion implanted oxygen, and a novel manufacturing process for a bonded semiconductor wafer in which an ion implantation separation process is adopted. The novel bonded semiconductor wafer is manufactured by means of a bonding process and has a layered structure alternately stacked with semiconductor layers and insulator layers in two cycles or more, wherein at least one of the insulator layers is formed with ion implanted oxygen.

Semiconductor wafer and method for producing the same

A semiconductor device is disclosed which allows for ease of fabrication of CMOS LSI chips and is adapted to increase the mobility of electrons and holes. The semiconductor device comprises a substrate, an insulating layer formed over the substrate, and a stacked Si/SiGe/Si region comprising a first layer of Si, a layer of SiGe, and a second layer of Si which are sequentially formed in this order on the insulating layer. The topmost second layer of Si and the layer of SiGe are strained due to the difference in lattice constant between each layer in the stacked Si/SiGe/Si region. An n-MOSFET and a p-MOSFET are formed in the stacked region. The n-MOSFET has a surface channel consisting of the second Si layer, whereas the p-MOSFET has a double channel of a buried channel consisting of the SiGe layer and a surface channel consisting of the second Si layer.

Mosfet with strained channel layer

Atomic-order surface reaction processes on the group IV semiconductor surface are formulated based on the Langmuir-type surface adsorption and reaction scheme. In in situ doped Si 1-x Ge x epitaxial growth on the (100) surface in an SiH 4 -GeH 4 -dopant (PH 3 , B 2 H 6 or SiH 3 CH 3 )-H 2 gas mixture, the deposition rate, the Ge fraction and the dopant concentration are explained quantitatively by assuming that the reactant gas adsorption/reaction depends on the surface site materials and that the dopant incorporation in the grown film is conducted by Henry's law. The self-limiting formation of 1-3 monolayers of group IV or related atoms in the thermal adsorption and reaction of hydride gases (SiH 4 , GeH 4 , NH 3 , PH 3 , CH 4 and SiH 3 CH 3 ) on Si(100) and Ge(100) is also generalized based on the Langmuir-type model. The Si epitaxial growth over the phosphorus layer already formed on Si(100) by PH 3 treatment is achieved. Moreover, atomic layer-by-layer etching of Si and Ge is achieved by alternate chlorine supply and irradiation of low-energy Ar + ions, where the chlorine adsorption is described by the Langmuir-type model. Silicon nitride is also etched layer by layer via a role-share method with an argon and hydrogen mixed plasma. These results open the way to atomically controlled processing for ultra-large-scale integration.

Takashi Matsuura

Papers

Electrical Conductivity and Seebeck Coefficient of Nonstoichiometric La1 − x Sr x CoO3 − δ

Self‐limited layer‐by‐layer etching of Si by alternated chlorine adsorption and Ar+ ion irradiation

Semiconductor wafer and method for producing the same

Mosfet with strained channel layer

Atomically controlled processing for group IV semiconductors