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:
Dec. 14, 2004
Filed:
May. 14, 2003
Hirofumi Kan, Hamamatsu, JP;
Minoru Niigaki, Hamamatsu, JP;
Masashi Ohta, Shizuoka, JP;
Yasufumi Takagi, Hamamatsu, JP;
Shoichi Uchiyama, Hamamatsu, JP;
Hamamatsu Photonics K.K., Shizuoka, JP;
Abstract
Ultraviolet light incident from the side of a surface layer passes through the surface layer to reach an optical absorption layer . Light which reaches the optical absorption layer is absorbed within the optical absorption layer , and photoelectrons are generated within the optical absorption layer . Photoelectrons diffuse within the optical absorption layer , and reach the interface between the optical absorption layer and the surface layer . Because the energy band is curved in the vicinity of the interface between the optical absorption layer and surface layer , the energy of the photoelectrons is larger than the electron affinity in the surface layer , and so photoelectrons are easily ejected to the outside. Here, the optical absorption layer is formed from an Al Ga N layer with an Mg content concentration of not less than 2×10 cm but not more than 1×10 cm , so that a solar-blind type semiconductor photocathode with high quantum efficiency is obtained.