Abstract: A power generation element includes a first crystal region including Alx1Ga1-x1N (0<x1?1), and a second crystal region including a first element and Alx2Ga1-x2N (0?x2<x1). The first element includes at least one selected from the group consisting of Si, Ge, Te, and Sn. The first crystal region includes a first surface and a second surface. The second surface is between the second crystal region and the first surface. The second crystal region includes a third surface and a fourth surface. The third surface is between the fourth surface and the first crystal region. An orientation from the fourth surface toward the third surface is along a <0001> direction of the second crystal region. An orientation from the second surface toward the first surface is along a <000-1> direction of the first crystal region.

Abstract: According to one embodiment, a semiconductor device includes a first electrode, a second electrode, a third electrode, a semiconductor member, and a first crystal member. A direction from the first electrode toward the second electrode is aligned with a first direction. A position in the first direction of the third electrode is between positions in the first direction of the first electrode and the second electrode. The semiconductor member includes at least one selected from the group consisting of silicon carbide, silicon, carbon, and germanium. The semiconductor member includes a first region, and first and second partial regions. The first region is between the first and second electrodes in the first direction. A second direction from the first region toward the third electrode crosses the first direction. The first crystal member is provided between the first and third electrodes in the second direction.

Abstract: A switch device of an embodiment includes a first electrode including a first layer including at least one selected from the group consisting of B, C, Al, Si, and Ga, a second electrode separated from the first electrode, a first grid disposed between the first electrode and the second electrode, and a second grid disposed between the first grid and the second electrode.

Abstract: According to one embodiment, an electron-emitting element includes a first member and a second member. The first member includes a semiconductor member of an n-type. The second member includes a diamond member a p-type and includes at least one selected from the group consisting of diamond and graphite. The semiconductor member includes at least one selected from the group consisting of a first material, a second material, and a third material. The first material includes nitrogen and at least one selected from the group consisting of B, Al, In, and Ga. The second material includes at least one selected from the group consisting of ZnO and ZnMgO. The third material includes at least one selected from the group consisting of BaTiO3, PbTiO3, Pb(Zrx, Ti1-x)O3, KNbO3, LiNbO3, LiTaO3, NaxWO3, Zn2O3, Ba2NaNb5O5, Pb2KNb5O15, and Li2B4O7.

Abstract: According to one embodiment, a semiconductor device includes first to third electrodes, and first and second layers. A direction from the first electrode toward the second electrode is aligned with a first direction. A position in the first direction of the third electrode is between positions in the first direction of the first and second electrodes. The first layer includes at least one selected from the group consisting of silicon carbide, silicon, carbon, and germanium. The first layer includes first to sixth partial regions. A concentration of the first impurity in the fourth partial region is higher than a concentration of the first impurity in the fifth partial region and higher than a concentration of the first impurity in the sixth partial region. The second layer includes AlxGa1-xN (0<x?1). The second layer includes a first portion and a second portion.

Abstract: According to one embodiment, a power generation element includes a first conductive layer, a second conductive layer, a first member provided between the first conductive layer and the second conductive layer, and a second member separated from the first member and provided between the first member and the second conductive layer. The first member includes a first region including Alx1Ga1-x1N (0?x1<1), and a second region including Alx2Ga1-x2N (x1<x2?1) and being provided between the first region and the second member. A <000-1> direction of the first member has a component in an orientation from the first conductive layer toward the second conductive layer.

Abstract: A switch device of an embodiment includes a first electrode including a first layer including at least one selected from the group consisting of B, C, Al, Si, and Ga, a second electrode separated from the first electrode, a first grid disposed between the first electrode and the second electrode, and a second grid disposed between the first grid and the second electrode.

Abstract: According to one embodiment, a semiconductor device includes a first layer, a first electrode, and a first nitride region. The first layer includes a first material and a first partial region. The first material includes at least one selected from the group consisting of silicon carbide, silicon, carbon, and germanium. The first partial region is of a first conductivity type. The first conductivity type is one of an n-type or a p-type. A direction from the first partial region toward the first electrode is aligned with a first direction. The first nitride region includes Alx1Ga1-x1N (0?x1<1), is provided between the first partial region and the first electrode, is of the first conductivity type, and includes a first protrusion protruding in the first direction.

Abstract: According to one embodiment, a power generation element includes first and second conductive layers, and first and second members. The first member is provided between the first and second conductive layers. The first member includes a first crystal region and a first layer region. The first crystal region is between the first layer region and the first conductive layer. An orientation from negative to positive of a polarization of the first crystal region has a component in a first orientation from the first conductive layer toward the second conductive layer. The first layer region includes a first layer-shaped portion spreading along a first surface. The first surface crosses the first orientation. The first layer-shaped portion includes at least one of graphene and a transition metal dichalcogenide. The second member is provided between the first member and the second conductive layer and separated from the first member.

Abstract: According to one embodiment, a semiconductor device includes a first layer, a first electrode, and a first nitride region. The first layer includes a first material and a first partial region. The first material includes at least one selected from the group consisting of silicon carbide, silicon, carbon, and germanium. The first partial region is of a first conductivity type. The first conductivity type is one of an n-type or a p-type. A direction from the first partial region toward the first electrode is aligned with a first direction. The first nitride region includes Alx1/Ga1-x1/N (0?x1<1), is provided between the first partial region and the first electrode, is of the first conductivity type, and includes a first protrusion protruding in the first direction.

Abstract: An embodiment of a semiconductor device including a silicon carbide layer having a first and a second planes; a first silicon carbide region of first conductivity type in the silicon carbide layer; a second silicon carbide region of second conductivity type in the silicon carbide layer between the first silicon carbide region and the first plane; a third silicon carbide region of the first conductivity type in the silicon carbide layer located between the second silicon carbide region and the first plane; a first electrode located on a side of the first plane; a second electrode located on a side of the second plane; a gate electrode; an aluminum nitride layer containing an aluminum nitride crystal between the second silicon carbide region and the gate electrode; and an insulating layer between the aluminum nitride layer and the gate electrode and having a wider band gap than the aluminum nitride layer.

Abstract: An embodiment is a semiconductor device includes a silicon carbide layer having a first plane and a second plane facing the first plane; a gate electrode; an aluminum nitride layer located between the silicon carbide layer and the gate electrode, the aluminum nitride layer containing an aluminum nitride crystal; a first insulating layer located between the silicon carbide layer and the aluminum nitride layer; and a second insulating layer located between the aluminum nitride layer and the gate electrode and having a wider band gap than the aluminum nitride layer.

Abstract: According to one embodiment, a power generation element includes a first conductive layer, a second conductive layer, a first member, and a second member. The first member includes a first crystal and is provided between the first conductive layer and the second conductive layer. The first crystal has a wurtzite structure. The second member is separated from the first member and is provided between the first member and the second conductive layer. A <000-1> direction of the first crystal has a component from the first member toward the second member.

Abstract: According to one embodiment, a semiconductor device includes first to third regions, and first to third electrodes. The first region includes a first partial region, a second partial region, and a third partial region between the first and second partial regions. A direction from the first partial region toward the first electrode is aligned with a first direction. A direction from the second partial region toward the second electrode is aligned with the first direction. A second direction from the first electrode toward the second electrode crosses the first direction. A direction from the third partial region toward the third electrode is aligned with the first direction. At least a portion of the third region is provided between the first and second electrodes in the second direction. At least a portion of the second region is provided between the third and first regions.

Abstract: According to one embodiment, a semiconductor device includes a first electrode, a second electrode, a first semiconductor layer, and a second semiconductor layer. The second electrode is separated from the first electrode in a first direction. The first semiconductor layer includes n-type SiC, is provided between the first electrode and the second electrode, and is electrically connected to the first electrode. The second semiconductor layer contacts the first semiconductor layer and the second electrode, is provided between the first semiconductor layer and the second electrode, and includes n-type AlxGa1-xN (0.5?x?1). A thickness of the second semiconductor layer is not less than 10 nm and not more than 1 ?m.

Abstract: According to one embodiment, a semiconductor device includes first to third regions, and first to third electrodes. The first region includes a first partial region, a second partial region, and a third partial region between the first and second partial regions. A direction from the first partial region toward the first electrode is aligned with a first direction. A second direction from the first electrode toward the second electrode crosses the first direction. A direction from the third partial region toward the third electrode is aligned with the first direction. A position of the third electrode is between a position of the first electrode and a position of the second electrode in the second direction. At least a portion of the second region is provided between the first and second electrodes. At least a portion of the third region is provided between the first and second regions.

Abstract: According to one embodiment, a semiconductor device includes a first electrode, a second electrode, a third electrode, a semiconductor member, and a first crystal member. A direction from the first electrode toward the second electrode is aligned with a first direction. A position in the first direction of the third electrode is between positions in the first direction of the first electrode and the second electrode. The semiconductor member includes at least one selected from the group consisting of silicon carbide, silicon, carbon, and germanium. The semiconductor member includes a first region, and first and second partial regions. The first region is between the first and second electrodes in the first direction. A second direction from the first region toward the third electrode crosses the first direction. The first crystal member is provided between the first and third electrodes in the second direction.

Abstract: According to one embodiment, a semiconductor device includes first to third electrodes, and first and second layers. A direction from the first electrode toward the second electrode is aligned with a first direction. A position in the first direction of the third electrode is between positions in the first direction of the first and second electrodes. The first layer includes at least one selected from the group consisting of silicon carbide, silicon, carbon, and germanium. The first layer includes first to sixth partial regions. A concentration of the first impurity in the fourth partial region is higher than a concentration of the first impurity in the fifth partial region and higher than a concentration of the first impurity in the sixth partial region. The second layer includes AlxGa1-xN (0<x1). The second layer includes a first portion and a second portion.

Abstract: According to one embodiment, a semiconductor device includes first, second and third electrodes, first, second, third, and fourth semiconductor regions, and an insulating portion. The first electrode includes first and second electrode portions. The first semiconductor region includes first, second, and third semiconductor portions. The first semiconductor portion is provided between the first electrode portion and the second electrode. The second semiconductor portion is provided between the second electrode portion and the third electrode. The third semiconductor portion is provided between the first and second semiconductor portions. The second semiconductor region is provided between the first semiconductor portion and the second electrode. The third semiconductor region is positioned between the second semiconductor region and the third electrode. The insulating portion includes first and second insulating regions.

Abstract: According to one embodiment, a power generation element includes a first conductive layer, a second conductive layer, a first member provided between the first conductive layer and the second conductive layer, and a second member separated from the first member and provided between the first member and the second conductive layer. The first member includes a first region including Alx1Ga1-x1N (0?x1<1), and a second region including Alx2Ga1-x2N (x1<x2?1) and being provided between the first region and the second member. A <000-1> direction of the first member has a component in an orientation from the first conductive layer toward the second conductive layer.