Abstract: A photocatalyst material (1A) in accordance with an aspect of the present invention includes a core particle (2) and a shell layer (3) with which a whole surface of the core particle (2) is covered. The core particle (2) contains at least a tungsten oxide, and the shell layer (3) is constituted by a titanium oxide.

Abstract: To provide a photocatalyst material having alkaline resistance and showing less deterioration in photocatalyst performance due to a poisoning effect and to provide a method for producing the photocatalyst material, a photocatalyst material (1A) according to one embodiment of the present invention includes: core particles (2) containing tungsten oxide; a promoter (4) formed on the surface of the core particles (2); and a shell layer (3) made of titanium oxide and covering the entire surface of both the core particles (2) and the promoter (4).

Abstract: To provide a photocatalyst material having alkaline resistance and showing less deterioration in photocatalyst performance due to a poisoning effect and to provide a method for producing the photocatalyst material, a photocatalyst material (1A) according to one embodiment of the present invention includes: core particles (2) containing tungsten oxide; a promoter (4) formed on the surface of the core particles (2); and a shell layer (3) made of titanium oxide and covering the entire surface of both the core particles (2) and the promoter (4).

Abstract: A photocatalyst material (1A) in accordance with an aspect of the present invention includes a core particle (2) and a shell layer (3) with which a whole surface of the core particle (2) is covered. The core particle (2) contains at least a tungsten oxide, and the shell layer (3) is constituted by a titanium oxide.

Abstract: An epitaxial wafer for a heterojunction type FET includes an AlN primary layer, a stepwisely composition-graded buffer layer structure, a superlattice buffer layer structure, a GaN channel layer, and a nitride semiconductor electron supply layer, which are sequentially provided on a Si substrate, the stepwisely composition-graded buffer layer structure including a plurality of AlGaN buffer layers provided on each other such that an Al composition ratio is sequentially reduced, an uppermost layer thereof having a composition of AlxGa1?xN (0<x), a plurality of sets of an AlyGa1?yN (y?1) superlattice constituting layer and an AlzGa1?zN (0<z<y) superlattice constituting layer being provided on each other alternately starting from one of the AlyGa1?yN superlattice constituting layer and the AlzGa1?zN superlattice constituting layer in the superlattice buffer layer structure, the AlxGa1?xN buffer layer and the AlzGa1?zN superlattice constituting layer satisfying x?0.05?z?x+0.05.

Abstract: A group III nitride semiconductor multilayer substrate (100) includes a channel layer (5) which is a group III nitride semiconductor, a barrier layer (6) which is formed on the channel layer (5) to form a heterointerface in combination with the channel layer (5) and which is a group III nitride semiconductor, wherein in the barrier layer (6, 206), a Cu concentration in a region of 10 nm or less depths from its surface is 1.0×1010 (atomicity/cm2) or less.

Abstract: An epitaxial wafer for a heterojunction type FET includes an AlN primary layer, a stepwisely composition-graded buffer layer structure, a superlattice buffer layer structure, a GaN channel layer, and a nitride semiconductor electron supply layer, which are sequentially provided on a Si substrate, the stepwisely composition-graded buffer layer structure including a plurality of AlGaN buffer layers provided on each other such that an Al composition ratio is sequentially reduced, an uppermost layer thereof having a composition of AlxGa1—xN (0<x), a plurality of sets of an AlyGa1?yN (y?1) superlattice constituting layer and an AlzGa1?zN (0<z<y) superlattice constituting layer being provided on each other alternately starting from one of the AlyGa1?yN superlattice constituting layer and the AlzGa1?zN superlattice constituting layer in the superlattice buffer layer structure, the AlxGa1?xN buffer layer and the AlzGa1?zN superlattice constituting layer satisfying x?0.05?z?x+0.05.