TYPE-II SUPERLATTICE PHOTODETECTOR WITH LOW-THICKNESS ABSORPTION REGION

Abstract

The present invention discloses a type-II superlattice photodetector with a low-thickness absorption region. The absorption region of the type-II superlattice photodetector includes an In(Bi)As layer and a Ga(N)Sb layer. The Bi element content in the In(Bi)As layer is less than 10%, and the Bi element content in the Ga(N)Sb layer is less than 5%. The present invention forms an InBiAs layer and a GaNSb layer by condensing the Bi element into the InAs layer and condensing the N element into the GaSb layer of a traditional InAs/GaSb type-II superlattice photodetector. Therefore, without changing the cut-off wavelength and performance of the detector, periodic and total thicknesses of the type-II superlattice photodetector material can be effectively reduced, and both costs of material use and molecular beam epitaxy can be reduced. In addition, the overall absorption coefficient of the material can be improved, and the volume of the entire device can be reduced.

Claims

1. A type-II superlattice photodetector with a low-thickness absorption region, wherein the absorption region of the type-II superlattice photodetector includes an In(Bi)As layer and a Ga(N)Sb layer. The Bi element content in the In(Bi)As layer is less than 10%, and the Bi element content in the Ga(N)Sb layer is less than 5%.

2. The type-II superlattice photodetector with a low-thickness absorption region of claim 1, wherein the structure of the absorption region is as follows: 10 ML InB.sub.0.05As.sub.0.95/15 ML GaN.sub.0.05Sb.sub.0.95.

3. The type-II superlattice photodetector with a low-thickness absorption region of claim 2, wherein the preparation includes the following steps: epitaxially growing the In(Bi)As layer on a substrate, controlling the Bi element content to be less than 10%, and controlling the thickness of the In(Bi)As layer to 10 ML; growing the Ga(N)Sb layer on the In(Bi)As layer, controlling the Bi element content to be less than 5%, and controlling the thickness of the Ga(N)Sb layer to 15 ML; conducting annealing treatment. The annealing temperature is 150-300° C.

Description

DETAILED DESCRIPTION

[0011] A type-II superlattice photodetector with a low-thickness absorption region is provided. The absorption region of the type-II superlattice photodetector includes an In(Bi)As layer and a Ga(N)Sb layer. The Bi element content in the In(Bi)As layer is less than 10%, and the Bi element content in the Ga(N)Sb layer is less than 5%. [0012] The structure of the absorption region is as follows: [0013] 10 ML InB.sub.0.05As.sub.0.95/15 ML GaN.sub.0.05Sb.sub.0.95. [0014] The type-II superlattice photodetector with a low-thickness absorption region of claim 2, wherein the preparation includes the following steps: [0015] 1) epitaxially growing the In(Bi)As layer on a substrate, controlling the Bi element content to be less than 10%, and controlling the thickness of the In(Bi)As layer to 10 ML; [0016] 2) growing the Ga(N)Sb layer on the In(Bi)As layer, controlling the Bi element content to be less than 5%, and controlling the thickness of the Ga(N)Sb layer to 15 ML; [0017] 3) conducting annealing treatment.

[0018] The preferred embodiments of the present invention are described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and changes according to concepts of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art through logical analysis, inference or limited experiments according to concepts of the present invention on the basis of the prior art should fall within the protection scope defined by the claims.