摘要:
A positive-electrode active material with improved electrical conductivity, and a power storage device using the material are provided. A positive-electrode active material with large capacity, and a power storage device using the material are provided. A core including lithium metal oxide is used as a core of a main material of the positive-electrode active material, and one to ten pieces of graphene is used as a covering layer for the core. A hole is provided for graphene, whereby transmission of a lithium ion is facilitated, resulting in improvement of use efficiency of current.
摘要:
To provide a lithium-ion secondary battery having higher discharge capacity and higher energy density and a manufacturing method thereof. The lithium-ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode. The positive electrode includes a positive electrode current collector and a positive electrode active material layer provided over the positive electrode current collector. In the positive electrode active material layer, graphenes and lithium-containing composite oxides are alternately provided. The lithium-containing composite oxide is a flat single crystal particle in which the length in the b-axis direction is shorter than each of the lengths in the a-axis direction and the c-axis direction. Further, the lithium-containing composite oxide is provided over the positive electrode current collector so that the b-axis of the single crystal particle intersects with a surface of the positive electrode current collector.
摘要:
To provide a lithium-ion secondary battery having higher discharge capacity and higher energy density and a manufacturing method thereof. The lithium-ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode. The positive electrode includes a positive electrode current collector and a positive electrode active material layer provided over the positive electrode current collector. In the positive electrode active material layer, graphenes and lithium-containing composite oxides are alternately provided. The lithium-containing composite oxide is a flat single crystal particle in which the length in the b-axis direction is shorter than each of the lengths in the a-axis direction and the c-axis direction. Further, the lithium-containing composite oxide is provided over the positive electrode current collector so that the b-axis of the single crystal particle intersects with a surface of the positive electrode current collector.
摘要:
The present invention relates to a power storage system including a negative electrode which has a crystalline silicon film provided as a negative electrode active material on the surface of a current collector and contains a conductive oxide in a surface layer section of the crystalline silicon film. Alternatively, the present invention relates to a method for manufacturing a power storage system, which includes the step of forming an amorphous silicon film on a current collector, adding a catalytic element for promoting crystallization of the amorphous silicon, onto a surface of the amorphous silicon film, heating the amorphous silicon film with the catalytic element added to crystallize the amorphous silicon film and thereby form a crystalline silicon film, and using the crystalline silicon film as a negative electrode active material layer.
摘要:
An electrode for an energy storage device with less deterioration due to charge and discharge, and a method for manufacturing thereof are provided. Further, an energy storage device having large capacity and high endurance can be provided. In an electrode of an energy storage device in which an active material is formed over a current collector, the surface of the active material is formed of a crystalline semiconductor film having a {110} crystal plane. The crystalline semiconductor film having a {110} crystal plane may be a crystalline silicon film containing a metal element which reacts with silicon to form a silicide. Alternatively, the crystalline semiconductor film having a {110} crystal plane may be a crystalline semiconductor film containing silicon as its main component and also containing germanium and a metal element which reacts with silicon to form a silicide.
摘要:
It is an object to provide a highly reliable semiconductor device with good electrical characteristics and a display device including the semiconductor device as a switching element. In a transistor including an oxide semiconductor layer, a needle crystal group provided on at least one surface side of the oxide semiconductor layer grows in a c-axis direction perpendicular to the surface and includes an a-b plane parallel to the surface, and a portion except for the needle crystal group is an amorphous region or a region in which amorphousness and microcrystals are mixed. Accordingly, a highly reliable semiconductor device with good electrical characteristics can be formed.
摘要:
A thin film transistor includes, as a buffer layer, a semiconductor layer which contains nitrogen and includes crystal regions in an amorphous structure between a gate insulating layer and source and drain regions, at least on the source and drain regions side. As compared to a thin film transistor in which an amorphous semiconductor is included in a channel formation region, on-current of a thin film transistor can be increased. In addition, as compared to a thin film transistor in which a microcrystalline semiconductor is included in a channel formation region, off-current of a thin film transistor can be reduced.
摘要:
An island-shaped single crystal semiconductor layer whose top surface has a plane within ±10° from a {211} plane is formed on an insulating surface; a non-single-crystal semiconductor layer is formed in contact with the top surface and a side surface of the single crystal semiconductor layer and on the insulating surface; the non-single-crystal semiconductor layer is irradiated with laser light to melt the non-single-crystal semiconductor layer, and to crystallize the non-single-crystal semiconductor layer formed on the insulating surface with use of the single crystal semiconductor layer as a seed crystal, so that a crystalline semiconductor layer is formed. A semiconductor device having an n-channel transistor and a p-channel transistor formed with use of the crystalline semiconductor layer is provided.
摘要:
In a channel protected thin film transistor in which a channel formation region is formed using an oxide semiconductor, an oxide semiconductor layer which is dehydrated or dehydrogenated by a heat treatment is used as an active layer, a crystal region including nanocrystals is included in a superficial portion in the channel formation region, and the rest portion is amorphous or is formed of a mixture of amorphousness/non-crystals and microcrystals, where an amorphous region is dotted with microcrystals. By using an oxide semiconductor layer having such a structure, a change to an n-type caused by entry of moisture or elimination of oxygen to or from the superficial portion and generation of a parasitic channel can be prevented and a contact resistance with a source and drain electrodes can be reduced.
摘要:
The thin film transistor includes a gate insulating layer covering a gate electrode, over a substrate having an insulating surface; a semiconductor layer forming a channel formation region, in which a plurality of crystal regions is included in an amorphous structure; an impurity semiconductor layer imparting one conductivity type which forms a source region and a drain region; and a buffer layer formed from an amorphous semiconductor, which is located between the semiconductor layer and the impurity semiconductor layer. The thin film transistor includes the crystal region which includes minute crystal grains and inverted conical or inverted pyramidal grain each of which grows approximately radially from a position away from an interface between the gate insulating layer and the semiconductor layer toward a direction in which the semiconductor layer is deposited in a region which does not reach the impurity semiconductor layer.