US4065780A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tunnel injection of minority carriers in semi-conductors
Assignee: Cornell Research Foundation Inc
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Filing: 1975-12-08
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Granted: 1977-12-27
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Expires: 1995-12-08
Abstract
Abstract Disclosed are multi-layer thin-film devices having adjacent insulator-semiconductor layers employing n-or-p-type semiconductors wherein a charge maintained at the insulator-semiconductor interface creates a depletion region that substantially suppresses tunneling of majority carriers while enhancing tunneling of minority carriers. When employed in a metal-insulator semiconductor (MIS) device wherein the semiconductor is a compound such as gallium arsenide (GaAs) or Cadmium Sulfide (CdS), such minority carrier injection substantially increases the luminescence efficiency.
Inventors
- 👤 Joseph M. Ballantyne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:43
CPC Classifications
H; H10; H10N; H10N80/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
72 words
In a multilayer thin-film device having adjacent insulator and semiconductor layers and producing an increased luminescence efficiency, the improvement which comprises: means to maintain a charge near the insulator-semiconductor interface of proper polarity and sufficient magnitude to create a depletion region in said semiconductor layer that substantially reduces majority carrier tunneling from the conduction band of said semiconductor layer and enhances minority carrier injection into said semiconductor layer and the resulting luminescence.
Claim 2
Dependent Claim
72 words
In a multilayer thin-film device having adjacent insulator and semiconductor layers and producing an increased luminescence efficiency, the improvement which comprises: means to maintain a charge near the insulator-semiconductor interface of proper polarity and sufficient magnitude to create a depletion region in said semiconductor layer that substantially reduces majority carrier tunneling from the conduction band of said semiconductor layer and enhances minority carrier injection into said semiconductor layer and the resulting luminescence.
Claim 3
Dependent Claim
29 words
A device according to claim 1, wherein said means to maintain a charge includes means for introducing a surface state at said insulator-semiconductor interface which produces said depletion region.
Claim 4
Dependent Claim
17 words
A device according to claim 1 wherein said multilayer thin-film device is of the semiconductor-insulator-semiconductor (SIS) type.
Claim 5
Dependent Claim
33 words
A device according to claim 1 wherein said means to maintain a charge near the insulator-semiconductor interface includes a semiconductor surface adjacent to said insulator which is substantially free of oxides and contaminants.
Claim 6
Dependent Claim
28 words
A device according to claim 4 wherein said semiconductor surface which is substantially free of oxides and contaminants is produced by cleaning in the presence of high vacuum.
Claim 7
Dependent Claim
13 words
A device according to claim 5 wherein said cleaning employs sputter-etching or ion-milling.
Claim 8
Dependent Claim
151 words
A multilayer thin-film device for producing electroluminescence, comprising: a first layer of semiconductor material; means forming a depletion region at a first surface of said semiconductor layer; a second, thin-film layer of insulator material deposited on said first surface of said semiconductor layer; a third layer of metal material deposited on said insulator material; means for applying a bias voltage across said device, said bias voltage and said depletion region cooperating to produce band-bending in the energy band gap of said semiconductor adjacent the interface between said first and second layers to substantially reduce majority carrier tunneling from the conduction band of said first layer to said third layer, and to lower the voltage threshold for minority carrier tunneling into said first layer from said third layer to less than the band gap of said semiconductor material of said first layer whereby minority carrier tunneling is enhanced to produce improved electroluminescence.
Claim 9
Dependent Claim
151 words
A multilayer thin-film device for producing electroluminescence, comprising: a first layer of semiconductor material; means forming a depletion region at a first surface of said semiconductor layer; a second, thin-film layer of insulator material deposited on said first surface of said semiconductor layer; a third layer of metal material deposited on said insulator material; means for applying a bias voltage across said device, said bias voltage and said depletion region cooperating to produce band-bending in the energy band gap of said semiconductor adjacent the interface between said first and second layers to substantially reduce majority carrier tunneling from the conduction band of said first layer to said third layer, and to lower the voltage threshold for minority carrier tunneling into said first layer from said third layer to less than the band gap of said semiconductor material of said first layer whereby minority carrier tunneling is enhanced to produce improved electroluminescence.
Claim 10
Dependent Claim
26 words
The device of claim 7, wherein said first layer is GaAs, said second layer is Al 2 O 3 , and said third layer is Al.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-26 | 1981-06-27 | 1981-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-26 | 1985-06-27 | 1985-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-26 | 1989-06-27 | 1989-12-27 | $7700.00 | Window Closed / Lapsed |