Hamamatsu-photonics K.k.

Sanken Electric Co., Ltd.

Shizuoka University

Hamamatsu Photonics Kabushiki Kaisha

Tokuaki Nihashi

Shunro Fuke

Masatomo Sumiya

Minoru Hagino

Minoru Niigaki

Toru Hirohata

Tetsuji Matsuo

Tuneo Ihara

Hideki Suzuki

Yoshihiro Ishigami

Masashi Ohta

The object is to provide a photoelectric surface member which allows higher quantum efficiency. In order to achieve this object, a photoelectric surface memberis a crystalline layer formed by a nitride type semiconductor material, and comprises a nitride semiconductor crystal layerwhere the direction from the first surfaceto the second surfaceis the negative c polar direction of the crystal, an adhesive layerformed along the first surfaceof the nitride semiconductor crystal layer, and a glass substratewhich is adhesively fixed to the adhesive layersuch that the adhesive layeris located between the glass substrateand the nitride semiconductor crystal layer

Process for producing layered member and layered member

A semiconductor photocathode includes an AlGaN layer (0&#x2266;X&#x3c;1) bonded to a glass substrate via an SiOlayer and an alkali-metal-containing layer formed on the AlGaN layer. The AlGaN 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 SiOlayer at least in the intermediate region.

Semiconductor photocathode and method for manufacturing the same

Disclosed is a photoelectric surface including: a first group III nitride semiconductor layer that produces photoelectrons according to incidence of ultraviolet rays; and a second group III nitride semiconductor layer provided adjacent to the first group III nitride semiconductor layer and made of a thin-film crystal having c-axis orientation in a thickness direction, the second group III nitride semiconductor layer having an Al composition higher than that of the first group III nitride semiconductor layer.

Photoelectric surface and photodetector

A photocathode having a UV glass substrate and a laminate composed of a SiO layer, a GaAlN layer, a Group III-V nitride semiconductor layer and an AlN buffer layer provided on the UV glass substrate in succession. The UV glass substrate, which absorbs infrared rays, can be heat treated at a high speed by photoheating. Further, the UV glass substrate, which is transparent to ultraviolet rays, permits ultraviolet rays to be introduced into the Group III-V nitride semiconductor layer where photoelectric conversion occurs.

Photocathode

After a film made of SiO,is formed on at least a part of a bonding surface of a first glass member, a part of or the whole bonding surface being formed with a metal film, a second glass member is hot-pressed against the bonding surface at a predetermined pressure and a predetermined temperature. As the second glass member is hot-pressed by way of the SiO,film against the bonding surface of the first member made of glass or the like having its bonding surface formed with a metal film, the two glass members are firmly bonded together, the bonding surface would be less likely to peel off, and the metal film would not be damaged.

Method of bonding glass members

The present invention relates to a photocathode having a structure for improving the quantum efficiency and sharpening the absorption edge characteristic on the long wavelength side within the wavelength range of incident light to improve the photosensitivity, and an electron tube having the same. The photocathode according to the present invention comprises at least a p-type GaAlN layer for absorbing incident light to excite photoelectrons, a p-type GaN layer which covers the second major surface of the p-type GaAlN layer, the second major surface opposing a first major surface that faces a substrate, and a surface layer provided to sandwich the p-type GaN layer with the p-type GaAlN layer and mainly containing an alkali metal or an alkali metal oxide.

Photocathode and electron tube having enhanced absorption edge

Formed on a semiconductor substrate (10) is a first semiconductor layer (20; light absorbing layer) of p-type which has a first dopant concentration and generates an electron in response to light incident. Formed on the first semiconductor layer (20) is a second semiconductor layer (30; electron transfer layer) of p-type having a second dopant concentration lower than the first dopant concentration. A contact layer (50) forms a pn junction with the p-type second semiconductor layer (30). A surface electrode (80) is formed on and in ohmic contact with the contact layer (50). A third semiconductor layer (40; activation layer) is formed within an opening of the contact layer (50) on the surface of the second semiconductor layer (30). Embedded in the second semiconductor layer (30) is a semiconductor section (60; channel grid) having a third dopant concentration. Thus, the quantum efficiency is improved, while structural pixel separation becomes unnecessary at an open area ratio of 100%, and signal modulation is enabled.

Semiconductor photocathode and semiconductor photocathode apparatus

Disclosed is a new type of transparent GaAs photo electric layer formed on an optical window made of a GaP single crystal substrate via an Al.sub.x Ga.sub.(1-x) As buffer layer, in which a gradual-lattice-constant layer of quadruple Al.sub.x Ga.sub.(1-x) PyAs.sub.(1-y) compound crystal is formed between the GaP single crystal substrate and the Al.sub.x Ga.sub.(1-x) As buffer layer. The y content in the gradual-lattice-constant layer of quadruple Al.sub.x Ga.sub.(1-x) PyAs.sub.(1-y) compound crystal changes from 1 to 0 as deposition of the gradual-lattice-constant layer of quadruple Al.sub.x Ga.sub.(1-x) PyAs.sub.(1-y) compound crystal goes on while the x content can arbitrarily be selected in the range of 0 to 1.

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Hamamatsu, Japan

Tokuaki Nihashi