The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 17, 2015
Filed:
Mar. 22, 2013
Sanken Electric Co., Ltd., Niiza-shi, Saitama, JP;
Hamamatsu Photonics K.k., Hamamatsu-shi, Shizuoka, JP;
Shunro Fuke, Hamamatsu, JP;
Tetsuji Matsuo, Niiza, JP;
Yoshihiro Ishigami, Hamamatsu, JP;
Tokuaki Nihashi, Hamamatsu, JP;
Sanken Electric Co., Ltd., Niiza-shi, Saitama, JP;
Hamamatsu Photonics K.K., Hamamatsu-shi, Shizuoka, JP;
Abstract
A semiconductor photocathode includes an AlGaN layer (0≦X<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.