US 8,179,585 B2 · Coupled quantum well structure

Abstract

In the production of optical devices or the like utilizing an intersubband transition of a coupled quantum well, a quantum well structure having strong coupling is provided. In addition, a coupled well structure of excellent productivity capable of avoiding thinning of coupling barrier layer for strengthening the coupling is provided. In the semiconductor coupled well structure of the present invention, a coupled quantum well structure disposed on the semiconductor single crystal substrate includes a coupling barrier layer 1a disposed between two or more quantum well layers 2a and 2b, wherein the coupling barrier layer 1a has an energy barrier that is smaller than an excitation level (E4 and E3) and is larger than a ground level (E2 and E1).

Claims6

Dependent claims

A semiconductor coupled quantum structure, comprising:

at least a coupled quantum well structure disposed on a substrate,
wherein a coupling barrier layer disposed between quantum well layers has a band-offset (ΔEc1) that is smaller than band-offsets (ΔEc2) of the quantum well layers and outer barrier layers, the smaller band-offset (ΔEc2) is smaller than one selected from a plurality of excitation levels (E4 and E3), and is larger than one ground level selected from a plurality of ground levels (E2 and B1),
wherein the quantum well layers comprise InGaAs;
the coupling barrier layer comprises InAlAs or InAlGaAs;
the outer barrier layer comprises AlAsSb;
and all of the intersubband energy differences in the conduction band of the coupled quantum well structure is 36 meV or more.

3 more elements

Dependencies are inferred from the claim text.

Coupled quantum well structure

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Coupled quantum well structure

Life of this patent

Abstract

Claims6