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US4122486A Expired / Lapsed US ⏱️ 0.0 years remaining

Semiconductor light-emitting element

Assignee: Hitachi Ltd
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Filing: 1977-02-24
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Granted: 1978-10-24
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Expires: 1997-02-24
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Abstract

Abstract A light emitting element made of a group III - V compound semiconductor has a p-n junction and a hetero-junction which are identical; the mixing ratio (band gap) of a p-type layer on the light emitting side is sufficiently smaller than that of an n-type layer on the opposite side. The semiconductor light-emitting element is especially useful as a light source, for optical communications, photoexcitation, etc.

Inventors

  • 👤 Yuichi Ono
  • 👤 Makoto Morioka
  • 👤 Kazuhiro Ito
  • 👤 Mitsuhiro Mori
  • 👤 Masahiko Kawata
  • 👤 Kazuhiro Kurata

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 13:32
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/80; H10H20/81; H10H20/811; H10H20/822; H10H20/824

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 119 words
In a semiconductor light emitting device having a heterojunction and a p-n junction, wherein light is emitted from one side of said p-n junction, said p-n junction exhibiting characteristics of a hetero-junction, the improvement comprising a first semiconductor layer of p-type conductivity and a second semiconductor layer of n-type conductivity defining a p-n junction from which said light is emitted, said first semiconductor layer having a band gap smaller than that of said second semiconductor layer, wherein said first semiconductor layer has a band gap Ep, said second semiconductor layer has a band gap En, and wherein (En-Ep) - (twice the energy step of the conduction band) ≧ 3kT, where k is Boltzmann's constant and T is absolute temperature.
Claim 2
Dependent Claim 119 words
In a semiconductor light emitting device having a heterojunction and a p-n junction, wherein light is emitted from one side of said p-n junction, said p-n junction exhibiting characteristics of a hetero-junction, the improvement comprising a first semiconductor layer of p-type conductivity and a second semiconductor layer of n-type conductivity defining a p-n junction from which said light is emitted, said first semiconductor layer having a band gap smaller than that of said second semiconductor layer, wherein said first semiconductor layer has a band gap Ep, said second semiconductor layer has a band gap En, and wherein (En-Ep) - (twice the energy step of the conduction band) ≧ 3kT, where k is Boltzmann's constant and T is absolute temperature.
Claim 3
Dependent Claim 23 words
The improvement according to claim 1, wherein each of said first and second semiconductor layers is made from a group III-V semiconductor compound.
Claim 4
Dependent Claim 24 words
The improvement according to claim 2, wherein one of said first semiconductor layer is p-type GaAs and said second semiconductor layer is n-type gallium-aluminum-arsenide.
Claim 5
Dependent Claim 30 words
The improvement according to claim 2, wherein said second semiconductor layer is n-type Ga 1-x Al x As, where x < 0.35 and said first semiconductor layer is p-type gallium-aluminum-arsenide.
Claim 6
Dependent Claim 30 words
The improvement according to claim 1, wherein said device has a light emitting surface provided so that said hetero-junction lies between said light emitting surface and said first semiconductor layer.
Claim 7
Dependent Claim 130 words
A light-emitting semiconductor device having a light emitting surface comprising: a first semiconductor layer of a first p + -conductivity type having a first surface of which forms said light emitting surface: a second semiconductor layer of said p-conductivity type forming a hetero-junction with said first semiconductor layer; a third semiconductor layer of a n-conductivity type forming a p-n junction with said second semiconductor layer, said p-n junction having characteristics of a hetero-junction; and first and second electrodes ohmically coupled to said first and third semiconductor layers, respectively, wherein said second semiconductor layer has an energy gap Ep and said third semiconductor layer has an energy gap En, and wherein (En-Ep)-(twice the energy step of the conduction band) ≧ 3kT, where k is Boltzmann's constant and T is absolute temperature.
Claim 8
Dependent Claim 130 words
A light-emitting semiconductor device having a light emitting surface comprising: a first semiconductor layer of a first p + -conductivity type having a first surface of which forms said light emitting surface: a second semiconductor layer of said p-conductivity type forming a hetero-junction with said first semiconductor layer; a third semiconductor layer of a n-conductivity type forming a p-n junction with said second semiconductor layer, said p-n junction having characteristics of a hetero-junction; and first and second electrodes ohmically coupled to said first and third semiconductor layers, respectively, wherein said second semiconductor layer has an energy gap Ep and said third semiconductor layer has an energy gap En, and wherein (En-Ep)-(twice the energy step of the conduction band) ≧ 3kT, where k is Boltzmann's constant and T is absolute temperature.
Claim 9
Dependent Claim 32 words
The improvement according to claim 6, further comprising a fourth semiconductor layer of n + conductivity type disposed between and providing ohmic coupling between said third semiconductor layer and said second electrode.
Claim 10
Dependent Claim 55 words
The improvement according to claim 7, further comprising a layer of insulating material extending through respective apertures provided through said third and fourth semiconductor layers and into a groove partially extending into said second semiconductor layer, the cross-section of said apertures and groove for limiting the extent of the light generating region of said device.
Claim 11
Dependent Claim 12 words
The improvement according to claim 8, wherein said device is hemispherically shaped.
Claim 12
Dependent Claim 32 words
The improvement according to claim 6, wherein said second semiconductor layer is a p-type ternary compound group III-V semiconductor and said third semiconductor layer is an n-type ternary compound group III-V semiconductor.

References Cited (Backward Citations)

US4017881A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-10-23 1982-04-24 1982-10-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-10-23 1986-04-24 1986-10-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-10-23 1990-04-24 1990-10-24 $7700.00 Window Closed / Lapsed

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