EP0433542A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optoelectronic devices
Assignee: International Business Machines Corp
•
Filing: 1990-07-26
•
Granted: —
•
Expires: 2010-07-26
Abstract
Abstract The present invention is directed to novel optoelectronic devices, such as light emitters and detectors, that have a unique combination of semiconductor materials that provides a band arrangement resulting in improved efficiency of carrier injection. The devices are quantum well type devices in which discrete electronic states are formed by size quantization effects in the quantum well region. Electromagnetic radiation of emission and absorption occurs by the transition of electrons from a first energy state to a second energy state in either the conduction band or the valence band of the quantum well layer (12). The bands edges of the layers are offset such that under an appropriate bias, the discrete energy states reside in the bandgap of one of the electrodes (14) and in an allowed region of the other electrode (16), with one state residing in the conduction band of one electrode and the other state residing in the valence band of the other electrode. The wavelength of the emitted or detected light is inversely proportional to the energy difference between the first and second states. Wavelength customization is facilitated by techniques for adjusting the energy difference.
Inventors
- 👤 Leo Esaki
- 👤 Hideo Ohno
- 👤 Emilio Eugenio Mendez
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 18:05
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/80; H10H20/81; H10H20/811; H10H20/812; B; B82; B82Y; B82Y20/00; H01; H01S; H01S5/00; H01S5/30; H01S5/34; H10F; H10F77/00; H10F77/10; H10F77/14; H01S5/06; H01S5/062; H01S5/06203; H01S5/06206; H01S5/3401; H01S5/3402; H01S5/3418; H01S5/3419; H01S5/3422; H01S5/343; H01S5/34306
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
128 words
An optoelectronic device comprising: a first region (14, 34) of semiconductor material having conduction and valence allowed energy bands defined by corresponding band edges spaced apart by an energy bandgap; a second region (16, 36) of semiconductor material having conduction and valence energy bands defined by corresponding band edges spaced apart by an energy bandgap; and a quantum well active region (12, 32) of semiconductor material sandwiched between said first and second regions, said quantum well region having at least two energy states (E₁, E₂) under a bias voltage at least a first of said energy states residing within the bandgap of one of said first and second regions and simultaneously residing within one of said allowed energy bands of the other of said first and second regions.
Claim 2
Dependent Claim
50 words
The optoelectronic device of claim 1 wherein, under said bias voltage at least a second of said energy states resides within the bandgap of one of said first and second regions and simultaneously resides within one of the allowed energy bands of the other of said first and second regions.
Claim 3
Dependent Claim
51 words
The optoelectronic device of claim 2 wherein one of said first and second energy states resides in conduction band of one of said first and second regions and the other of said first and second energy states resides in the valence band of the other of said first and second regions.
Claim 4
Dependent Claim
65 words
The optoelectronic device of any one of the preceding claims further including at least a tunnel barrier disposed between said first or said second region and said quantum well region, preferably including a first tunnel barrier (18, 38) disposed between said first region and said quantum well region and a second tunnel barrier (20, 40) disposed between said second region and said quantum well region.
Claim 5
Dependent Claim
50 words
The optoelectronic device of claim 4 wherein said tunnel barriers are each comprised of a layer of semiconductor material having a bandgap wider than the bandgap of said quantum well region to provide carrier confinement and, to act as an insulator, said barriers being sufficiently thin to permit carrier tunnelling.
Claim 6
Dependent Claim
34 words
The optoelectronic device of any one of the preceding claims wherein said at least two energy states are located within one of the conduction band and the valence band of said quantum well region.
Claim 7
Dependent Claim
52 words
The optoelectronic device of any one of the preceding claims 4 to 6 wherein said first region, said first tunnel barrier and said quantum well region form a type I tunnel junction and wherein said quantum well region, said second tunnel barrier and said second region form a type II tunnel junction.
Claim 8
Dependent Claim
27 words
The optoelectronic device of any one of the preceding claims 4 to 7 wherein each of said tunnel barriers is formed by a zero thickness potential barrier.
Claim 9
Dependent Claim
43 words
The optoelectronic device of any one of the preceding claims further including means for applying a bias to said device sufficient to cause one of emission and absorption of electromagnetic energy between said first and second energy states in said quantum well region.
Claim 10
Dependent Claim
27 words
The optoelectronic device of claim 3 wherein said active region and at least one of said first region and said second region form a type II heterojunction.
Claim 11
Dependent Claim
39 words
The optoelectronic device of any one of the preceding claims wherein said first region is InAs, said second region is GaSb, said active region is one of InAs and GaSb, and, if present, said barrier layer is of ALSb.
Claim 12
Dependent Claim
41 words
The optoelectronic device of any one of the preceding claims 4 to 11 wherein said first region or said second region, respectively, said barrier layer and said active region form one of a type I and a type II tunnel junction.
Claim 13
Dependent Claim
50 words
The optoelectronic device of any one of the preceding claims 4 to 12 wherein said first region, said first barrier layer and said active region form a type II tunnel junction and wherein said active region, said second barrier layer and said second region form a type I tunnel junction.
Claim 14
Dependent Claim
117 words
The optoelectronic device of claims 2 or 4 wherein said first and second energy states are located within the conduction band of said active region, said device further including means for applying a bias to said device such that electrons are supplied to said active region from said first region at an energy level of about that of the higher of said first and second energy states, said electrons relaxing to the lower of said energy states thereby radiating electromagnetic energy inversely proportional to an energy of about the difference between the higher and lower energy states, said electrons being collected by said second region at an energy level of about the lower of said energy states.
Claim 15
Dependent Claim
117 words
The optoelectronic device of claims 2 or 4 wherein said first and second energy states are located within the valence band of said active region, said device further including means for applying a bias to said device such that holes are supplied to said active region from said first region at an energy level of about that of the higher of said first and second energy states, said holes relaxing to the lower of said energy states thereby radiating electromagnetic energy inversely proportional to an energy of about the difference between the higher and lower energy states, said holes being collected by said second region at an energy level of about the lower of said energy states.
Claim 16
Dependent Claim
32 words
The optoelectronic device of any one of the preceding claims 1 to 10 wherein under equilibrium, the Fermi level resides in the band gap of one of said first and second regions.
Claim 17
Dependent Claim
34 words
The optoelectronic device of claim 16 wherein said first region is AlInAsSb, said second region and said active region is one of InAs and GaSb, and, if present, said barrier layer is of AlSb.
Claim 18
Dependent Claim
120 words
The optoelectronic device of claims 16 or 17 wherein said first and second energy states are located within the conduction band of said active region, said device further including means for applying a reverse bias to said device such that electrons are supplied to said active region from said second region at an energy level of about that of the lower of said first and second energy states, said electrons being excited to the higher of said energy states by an absorption of electromagnetic energy inversely proportional to an energy of about the difference between the higher and lower energy states, said electrons being collected by said first region an energy level of about the higher of said energy states.
Claim 19
Dependent Claim
121 words
The optoelectronic device of claims 15 or 16 wherein said first and second energy states are located within the valence band of said active region, said device further including means for applying a reverse bias to said device such that holes are supplied to said active region from said second region at an energy level of about that of the lower of said first and second energy states, said holes being excited to the higher of said energy states by an absorption of electromagnetic energy inversely proportional to an energy of about the difference between the higher and lower energy states, said holes being collected by said first region at an energy level of about the higher of said energy states.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.