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:
Nov. 09, 1999
Filed:
Apr. 10, 1997
Tokuaki Nihashi, Hamamatsu, JP;
Toru Hirohata, Hamamatsu, JP;
Hideki Suzuki, Hamamatsu, JP;
Tuneo Ihara, Hamamatsu, JP;
Hamamatsu Photonics K.K., Hamamatsu, JP;
Abstract
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.