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US4075654A Expired / Lapsed US ⏱️ 0.0 years remaining

Semiconductor photoelectron emission device

Assignee: Hamamatsu Terebi KK
•
Filing: 1976-10-26
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Granted: 1978-02-21
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Expires: 1996-10-26
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Abstract

Abstract Semiconductor photoelectron emission device comprising mixed crystals of two or more different semiconductors forming a heterojunction with direct transition type defining a first region in which may be excited by photoelectrons and an indirect transition type defining a second region whose forbidden band gap is wider than that of the first region and the surface of which is a photoelectron emission surface.

Inventors

  • 👤 Katsuo Hara
  • 👤 Minoru Hagino
  • 👤 Tokuzo Sukegawa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 05:57
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/12; H01J1/00; H01J1/02; H01J1/34; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/39; H01J29/45; H01J29/451; H01J2201/00; H01J2201/34; H01J2201/342; H01J2201/3421; H01J2201/3423

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 141 words
A semiconductor photoelectron emission device comprising an electrode; a base of direct transition semiconductor of p-type GaSb having an impurity concentration of about 10 17 to 10 19 atom/cm 3 ; a first layer of n-type GaSb having a thickness of about 10μm epitaxially grown on and covering selected parts of said base; a second layer of indirect transition semiconductor of Al.sub.(1-x) Ga x Sb, wherein x is less than 1 and a positive number, having a wide forbidden band and low impurity concentration and of 500 A to 10μm thickness and defining a heterojunction with said base, said base and said second layer having substantially the same crystal structure at said junction and having small differences in lattice constants; a third layer of Al.sub.(1-x) Ga.sub.(1-x) Sb having a narrower forbidden band and with an electron emissive surface; and ohmic contacts.
Claim 2
Dependent Claim 141 words
A semiconductor photoelectron emission device comprising an electrode; a base of direct transition semiconductor of p-type GaSb having an impurity concentration of about 10 17 to 10 19 atom/cm 3 ; a first layer of n-type GaSb having a thickness of about 10μm epitaxially grown on and covering selected parts of said base; a second layer of indirect transition semiconductor of Al.sub.(1-x) Ga x Sb, wherein x is less than 1 and a positive number, having a wide forbidden band and low impurity concentration and of 500 A to 10μm thickness and defining a heterojunction with said base, said base and said second layer having substantially the same crystal structure at said junction and having small differences in lattice constants; a third layer of Al.sub.(1-x) Ga.sub.(1-x) Sb having a narrower forbidden band and with an electron emissive surface; and ohmic contacts.
Claim 3
Dependent Claim 14 words
The device of claim 1, wherein further comprising means for providing drift electric fields.
Claim 4
Dependent Claim 25 words
The device of claim 1, wherein lattice sites of the mixed crystals have atoms thereof replaced with other atoms of In, Bi, As and P.
Claim 5
Dependent Claim 18 words
The device of claim 1, wherein said GaSb has an effective forbidden band of 0.7 to 1.25 eV.
Claim 6
Dependent Claim 20 words
The device of claim 1, wherein said third layer has a thickness equivalent of less than the electron diffusion length.

References Cited (Backward Citations)

US3696262A Cited
US3814996A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-02-20 1981-08-22 1982-02-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-02-20 1985-08-22 1986-02-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-02-20 1989-08-22 1990-02-21 $7700.00 Window Closed / Lapsed

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