Abstract: A transmissive photocathode includes a light transmitting substrate that has a first surface on which light is incident and a second surface which emits light incident from a side of the first surface, a photoelectric conversion layer that is provided on the second surface side of the light transmitting substrate and converts the light emitted from the second surface into photoelectrons, a light transmitting conductive layer that is provided between the light transmitting substrate and the photoelectric conversion layer and is composed of a single-layered graphene, and a thermal stress alleviation layer that is provided between the photoelectric conversion layer and the light transmitting conductive layer and has light transmissivity. A thermal expansion coefficient of the thermal stress alleviation layer is smaller than a thermal expansion coefficient of the photoelectric conversion layer and larger than a thermal expansion coefficient of the graphene.

Abstract: A transmissive photocathode includes a light transmitting substrate that has a first surface on which light is incident and a second surface which emits light incident from a side of the first surface, a photoelectric conversion layer that is provided on the second surface side of the light transmitting substrate and converts the light emitted from the second surface into photoelectrons, a light transmitting conductive layer that is provided between the light transmitting substrate and the photoelectric conversion layer and is composed of a single-layered graphene, and a thermal stress alleviation layer that is provided between the photoelectric conversion layer and the light transmitting conductive layer and has light transmissivity. A thermal expansion coefficient of the thermal stress alleviation layer is smaller than a thermal expansion coefficient of the photoelectric conversion layer and larger than a thermal expansion coefficient of the graphene.

Abstract: A reference body 1 includes: a support 10 provided with a first light passing portion 18, a second light passing portion 19, a first accommodating space 14, and a second accommodating space 15; a first fluorescent body 20 accommodated in the first accommodating space 14 and configured to emit first fluorescence in a second wavelength band when irradiated with first excitation light in a first wavelength band through the first light passing portion 18; a second fluorescent body 30 accommodated in the second accommodating space 15 and configured to emit second fluorescence in the second wavelength band when irradiated with second excitation light in the first wavelength band through the second light passing portion 19; and a light shielding portion 13 disposed between the first accommodating space 14 and the second accommodating space 15.

Abstract: A semiconductor photocathode includes an AlXGa1-XN layer (0?X<1) bonded to a glass substrate via an SiO2 layer and an alkali-metal-containing layer formed on the AlXGa1-XN layer. The AlXGa1-XN layer includes a first region, a second region, an intermediate region between the first and second regions. The second region has a semiconductor superlattice structure formed by laminating a barrier layer and a well layer alternately, the intermediate region has a semiconductor superlattice structure formed by laminating a barrier layer and a well layer alternately. When a pair of adjacent barrier and well layers is defined as a unit section, an average value of a composition ratio X of Al in a unit section decreases monotonously with distance from an interface position between the second region and the SiO2 layer at least in the intermediate region.

Abstract: The present invention aims at providing a photocathode which can improve various characteristics. In a photocathode 10, an intermediate layer 14, an underlayer 16, and a photoelectron emission layer 18 are formed in this order on a substrate 12. The photoelectron emission layer 18 contains Sb and Bi and functions to emit a photoelectron in response to light incident thereon. The photoelectron emission layer 18 contains 32 mol % or less of Bi relative to SbBi. This can dramatically improve the linearity at low temperatures.

Abstract: A semiconductor photocathode includes an AlXGa1-XN layer (0?X<1) bonded to a glass substrate via an SiO2 layer and an alkali-metal-containing layer formed on the AlXGa1-XN layer. The AlXGa1-XN layer includes a first region, a second region, an intermediate region between the first and second regions. The second region has a semiconductor superlattice structure formed by laminating a barrier layer and a well layer alternately, the intermediate region has a semiconductor superlattice structure formed by laminating a barrier layer and a well layer alternately. When a pair of adjacent barrier and well layers is defined as a unit section, an average value of a composition ratio X of Al in a unit section decreases monotonously with distance from an interface position between the second region and the SiO2 layer at least in the intermediate region.

Abstract: The present invention aims at providing a photocathode which can improve various characteristics. In a photocathode 10, an intermediate layer 14, an underlayer 16, and a photoelectron emission layer 18 are formed in this order on a substrate 12. The photoelectron emission layer 18 contains Sb and Bi and functions to emit a photoelectron in response to light incident thereon. The photoelectron emission layer 18 contains 32 mol % or less of Bi relative to SbBi. This can dramatically improve the linearity at low temperatures.