US3634872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light-emitting diode with built-in drift field
Assignee: Hitachi Ltd
•
Filing: 1970-09-04
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Granted: 1972-01-11
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Expires: 1990-09-04
Abstract
Abstract An injection electroluminescent semiconductor device having a light emitting conductivity-type layer with a PN-junction. wherein the distribution of effective majority impurity concentration decreases, or when a mixed crystal semiconductor material is used the component having a greater forbidden band width is reduced, with the increase of the distance from the PN junction. This construction causes the formation of an internal electric field which keeps injected minority carriers away from the PN-junction. thereby increasing the penetration length of injected minority carriers and improving the quantum efficiency of light emission.
Inventors
- 👤 Junichi Umeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:49
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/80; Y; Y10; Y10S; Y10S148/00; Y10S148/049; Y10S148/056; Y10S148/057; Y10S148/065; Y10S148/067; Y10S148/072; Y10S148/119
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
38 words
An injection electroluminescent semiconductor device according to claim 1, wherein said light-emissive layer has a distribution of effective majority impurity concentration which decreases with the increase of the distance from said PN-junction, thereby forming said internal electric field.
Claim 2
Dependent Claim
44 words
An injection electroluminescent semiconductor device according to claim 2, wherein said distribution of effective majority impurity concentration decreasing with the increase of the distance from said PN-junction toward the surface opposite thereto increases again in the vicinity of said surface opposite to said PN-junction.
Claim 3
Dependent Claim
30 words
An injection electroluminescent semiconductor device according to claim 2, wherein said distribution of effective majority impurity concentration decreases at least to half by every diffusion length of injected minority carriers.
Claim 4
Dependent Claim
31 words
An injection electroluminescent semiconductor device according to claim 4, Wherein said semiconductor layers are made of a material selected from the group consisting of GaAs GaAs1 cPc(0<c<0.45) and Ga1 cAlcAs (0<c<0.45).
Claim 5
Dependent Claim
31 words
An injection electroluminescent semiconductor device according to claim 5, wherein said distribution of effective majority impurity concentration decreases at least to half by every 1 Mu of separation from said PN-junction.
Claim 6
Dependent Claim
42 words
An injection electroluminescent semiconductor device according to claim 4, wherein said semiconductor layers are made of GaP bulk crystal including oxygen atoms of not more than 1016 cm. 3 as impurity, whereby said semiconductor device emits green light under a forward bias.
Claim 7
Dependent Claim
31 words
An injection electroluminescent semiconductor device according to claim 7, wherein said distribution of effective majority impurity concentration decreases at least to half by every 1 Mu of separation from said PN-junction.
Claim 8
Dependent Claim
41 words
An injection electroluminescent semiconductor device according to claim 4, wherein said semiconductor layers are made of GaP bulk crystal including oxygen atoms of not less than 1016 cm. 3 impurity, whereby said semiconductor device emits red light under a forward bias.
Claim 9
Dependent Claim
31 words
An injection electroluminescent semiconductor device according to claim 9, wherein said distribution of effective majority impurity concentration decreases at least to half by every 1 Mu of separation from said PN-junction.
Claim 10
Dependent Claim
33 words
An injection electroluminescent semiconductor device according to claim 1, wherein the maximum effective majority impurity concentration in said light-emissive layer in the vicinity of said PN-junction is not less than 1016 cm. 3.
Claim 11
Dependent Claim
33 words
An injection electroluminescent semiconductor device according to claim 2, wherein the maximum effective majority impurity concentration in said light-emissive layer in the vicinity of the PN-junction is not less than 1016 cm. 3.
Claim 12
Dependent Claim
36 words
An injection electroluminescent semiconductor device according to claim 2, wherein said distribution of effective majority impurity concentration decreases linearly with respect to the distance from the PN junction at a rate greater than 1020 cm. 4.
Claim 13
Dependent Claim
17 words
An injection electroluminescent semiconductor device according to claim 1, wherein said light-emissive layer is a P-type layer.
Claim 14
Dependent Claim
17 words
An injection electroluminescent semiconductor device according to claim 2, wherein said light-emissive layer is a P-type layer.
Claim 15
Dependent Claim
32 words
An injection electroluminescent semiconductor device according to claim 13, wherein said device is made of a semiconductor material selected from the group consisting of GaAs GaP, GaAs1 cPc(0<c<0.45) and Ga1 cAlcAs (0<c<0.45).
Claim 16
Dependent Claim
48 words
An injection electroluminescent semiconductor device according to claim 1, wherein said device is made of a mixed crystal semiconductor material and said internal electric field is formed by reducing the content of the component having a wider forbidden band with the increase of the distance from said PN-junction.
Claim 17
Dependent Claim
17 words
An injection electroluminescent semiconductor device according to claim 17, wherein said light-emissive layer is a P-type layer.
Claim 18
Dependent Claim
34 words
An injection electroluminescent semiconductor device according to claim 17, wherein the conductivity-type layer other than said light emissive layer has a forbidden band width larger than the energy of light generated at the PN-junction.
Claim 19
Dependent Claim
31 words
An injection electroluminescent semiconductor device according to claim 17, wherein said semiconductor layers are made of a bulk crystal selected from the group consisting of GaAs1 cPc(0<c<0.45) and Ga1 cAlcAs (0<c<0.45).
Claim 20
Dependent Claim
32 words
An injection electroluminescent semiconductor Device according to claim 20, wherein one of the light-emissive layers has a portion in which c is reduced with the increase of the distance from said PN-junction.
Claim 21
Dependent Claim
32 words
An injection electroluminescent semiconductor device according to claim 21, wherein c decreases at least at a rate of not less than 0.01/ Mu with the increase of the distance from said PN-junction.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |