Quantum well laser epitaxial structure and quantum well laser

Abstract

The present disclosure provides a quantum well laser epitaxial structure and a quantum well laser, the epitaxial structure comprising: a substrate, a buffer layer, a lower cladding layer, a lower waveguide layer, a quantum well active region, an upper waveguide layer, an upper cladding layer and a contact layer stacked in sequence; wherein the lower cladding layer is used to limit the laser leakage to a first direction, and the upper cladding layer is used to limit the laser leakage to a second direction; the band gap width of the lower waveguide layer is between the lower cladding layer and the quantum well active region, and the band gap width of the lower waveguide layer is greater than the band gap width of the quantum well active region, and the refractive index of the lower waveguide layer is greater than the refractive index of the lower cladding layer; and the quantum well active region comprises one or more quantum well layers and a chirped barrier arranged in mutual overlap, and the chirped barrier is used to reflect electrons and holes to limit the recombination of the electrons and holes in the quantum well layer to emit light. The epitaxial structure of the present disclosure enhances the interaction of electrons and holes, can improve the optical gain, and reduce the device threshold current and improve the characteristic temperature.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of semiconductor lasers, and particularly relates to a quantum well laser epitaxial structure and a quantum well laser. BACKGROUND

[0002] The mid-infrared spectral region has a rich gas characteristic absorption peak, so that the laser working in this waveband has great application value in the fields of gas detection, industrial processing and scientific research. At the same time, as an important atmospheric transparent window, such devices also have great application value in the fields of infrared countermeasures and wireless communication.

[0003] Sb-based quantum well lasers have a band gap and rich energy band structure design that match the mid-infrared waveband, and have significant advantages in the 2-4 micron working waveband. However, research shows that the performance of Sb-based quantum well lasers will decrease significantly when the working wavelength exceeds 2.5 microns. This significant device performance deterioration comes from insufficient quantum well band step confinement. Therefore, improving the confinement of quantum wells on carriers, especially holes, is an important issue for improving the working performance of Sb-based lasers at long wavelengths.

[0004] The traditional scheme for improving the carrier confinement of quantum wells is to introduce a five-element alloy barrier AlGaInAsSb. Although the five-element alloy barrier can improve the confinement of holes to some extent, it will also weaken the confinement of electrons. Moreover, the growth window of the five-element alloy is very narrow, and it is difficult to grow. SUMMARY

[0005] (I) Technical problems to be solved

[0006] In view of the existing technical problems, the present disclosure provides a quantum well laser epitaxial structure and a quantum well laser, which are used to at least partially solve the above technical problems.

[0007] (II) Technical solutions

[0008] The present disclosure provides a quantum well laser epitaxial structure, comprising: a substrate, a buffer layer, a lower cladding layer, a lower waveguide layer, a quantum well active region, an upper waveguide layer, an upper cladding layer and a contact layer which are sequentially stacked; wherein the lower cladding layer is used to limit the laser leakage to a first direction, and the upper cladding layer is used to limit the laser leakage to a second direction; the band gap width of the lower waveguide layer is between the lower cladding layer and the quantum well active region, and the band gap width of the lower waveguide layer is greater than the band gap width of the quantum well active region, and the refractive index of the lower waveguide layer is greater than the refractive index of the lower cladding layer; the band gap width of the upper waveguide layer is between the upper cladding layer and the quantum well active region, and the band gap width of the upper waveguide layer is greater than the band gap width of the quantum well active region, and the refractive index of the upper waveguide layer is greater than the refractive index of the upper cladding layer; and the quantum well active region comprises one or more quantum well layers and a chirped barrier which are arranged in mutual overlap, and the chirped barrier is used to reflect electrons and holes in the quantum well layer to limit the recombination of the electrons and holes in the quantum well layer to emit light.

[0009] Optionally, the chirped barrier comprises: a short-period superlattice and a thin bulk material; wherein the number of periods of the short-period superlattice is 3-5, and the thickness of the thin bulk material is 5-20 nm.

[0010] Optionally, the short-period superlattice comprises: indium arsenide layers, aluminum antimony layers and gallium antimony layers which are stacked in any order; and the thin bulk material is Al 0.25～0.5 GaAsSb.

[0011] Optionally, the thickness and composition of the quantum well layer are determined according to the operating wavelength of the quantum well laser; wherein the composition of the quantum well layer is In 0.45-0.5 GaAs 0.18-0.2 Sb; and the thickness of the quantum well layer is 8-13 nm.

[0012] Optionally, the aluminum antimony layer is in contact with the quantum well layer.

[0013] Optionally, the lower cladding layer and the upper cladding layer are high-aluminum-component AlGaAsSb bulk materials, wherein the aluminum component is greater than or equal to 0.5.

[0014] Optionally, the lower waveguide layer and the upper waveguide layer are low-aluminum-component AlGaAsSb, wherein the aluminum component is less than or equal to 0.3.

[0015] Optionally, the material lattice of the substrate is matched with at least one of the materials of the buffer layer, the lower cladding layer, the lower waveguide layer, the quantum well active region, the upper waveguide layer, the upper cladding layer and the contact layer; wherein the material of the substrate is gallium antimony.

[0016] Optionally, the substrate, the buffer layer and the lower cladding layer are doped with N-type gallium tellurium doping; the upper cladding layer is P-type doping doped with beryllium; and the contact layer is a P-type beryllium-doped gallium antimony layer.

[0017] Another aspect of the present disclosure provides a quantum well laser, comprising: a quantum well laser epitaxial structure and a plurality of electrodes according to any one of the embodiments of the present disclosure; wherein one of the plurality of electrodes is in contact with the contact layer, and another of the plurality of electrodes is in contact with the substrate; and the operating wavelength of the quantum well laser is 2.6-2.9 μm.

[0018] (III) Beneficial Effects

[0019] Compared with the prior art, the quantum well laser epitaxial structure and the quantum well laser provided by the present disclosure have at least the following beneficial effects:

[0020] (1) The quantum well laser epitaxial structure of the present disclosure, by arranging the chirped barrier beside the quantum well layer of the multiple-period quantum well active region, has a high reflection effect on electrons and holes, can confine electrons and holes in the quantum well layer, enhances the interaction between electrons and holes, and thus can improve the optical gain, reduce the device threshold current, and improve the characteristic temperature.

[0021] (2) The quantum well laser epitaxial structure of the present disclosure, the chirped barrier is composed of a short-period superlattice and a thin layer of bulk material, without changing the electron energy level and the hole energy level in the quantum well layer, i.e. without affecting the emission wavelength of the quantum well layer.

[0022] (3) The quantum well laser epitaxial structure of the present disclosure specifically uses an aluminum antimony layer to connect with the quantum well layer, further improving the confinement effect on electrons and holes. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings, in which:

[0024] Figure 1A A layer structure diagram of a quantum well laser epitaxial structure according to an embodiment of the present disclosure is schematically shown; Figure 1B A layer structure diagram of a quantum well active region according to an embodiment of the present disclosure is schematically shown; Figure 1C A layer structure diagram of a chirped barrier according to an embodiment of the present disclosure is schematically shown;

[0025] Figure 2 A comparison diagram of a band diagram simulation of a quantum well active region based on a chirped barrier structure and a conventional quantum well active region according to an embodiment of the present disclosure is schematically shown;

[0026] Figure 3 A comparison diagram of electron and hole reflection energy spectrum based on a chirped barrier structure and a conventional quantum well active region according to an embodiment of the present disclosure is schematically shown;

[0027] Figure 4A growth flow chart of a quantum well laser epitaxial structure according to an embodiment of the present disclosure is schematically shown.

[0028] [Legend of Reference Signs]

[0029] 1 - substrate; 2 - buffer layer; 3 - lower cladding layer; 4 - lower waveguide layer; 5 - quantum well active region; 51 - quantum well layer; 52 - chirped barrier; 521 - short period superlattice; 522 - thin bulk material; 6 - upper waveguide layer; 7 - upper cladding layer; 8 - contact layer. DETAILED DESCRIPTION

[0030] In order to make the objects, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to specific embodiments and with reference to the drawings.

[0031] It should be noted that similar or identical parts are denoted by the same reference signs in the drawings or the description. The technical features in the example embodiments described in the specification can be freely combined as long as there is no conflict. In addition, each claim can stand alone as an embodiment, or the technical features in the claims can be combined as a new embodiment. In the drawings, the shape or thickness of the embodiments can be exaggerated and simplified for the purpose of convenience or clarity. Furthermore, elements or implementations not described in the drawings or the description are known to those skilled in the art. In addition, although examples can provide parameters including specific values, it should be understood that the parameters do not necessarily have to be exactly equal to the corresponding values, but can be approximately equal to the corresponding values within an acceptable error tolerance or design constraint.

[0032] The various embodiments of the present disclosure described above can be freely combined to form further embodiments, which are all within the scope of the present disclosure, unless there is a technical obstacle or conflict.

[0033] Although the present disclosure is described with reference to the drawings, the embodiments disclosed in the drawings are intended to exemplify the preferred embodiments of the present disclosure and should not be construed as limiting the present disclosure. The size ratio in the drawings is merely schematic and should not be construed as limiting the present disclosure.

[0034] Although some embodiments of the general concept of the present disclosure have been shown and described, those of ordinary skill in the art will understand that changes can be made in the embodiments without departing from the principles and spirit of the general concept of the present disclosure, and the scope of the present disclosure is defined by the claims and their equivalents.

[0035] First, the related terms of the embodiments of the present disclosure are explained as follows:

[0036] Superlattice: A multilayer film in which two different components are grown in thin layers of several nanometers to tens of nanometers and maintain strict periodicity, which is actually a specific form of layered fine composite material.

[0037] Bulk material: refers to a material with a three-dimensional spatial structure, a uniform crystal or amorphous substance.

[0038] Figure 1A The layer structure diagram of the quantum well laser epitaxial structure according to the embodiment of the present disclosure is schematically shown. Figure 1B The layer structure diagram of the quantum well active region according to the embodiment of the present disclosure is schematically shown.

[0039] According to the embodiment of the present disclosure, as Figure 1A shown, the quantum well laser epitaxial structure, for example, includes: a substrate 1, a buffer layer 2, a lower cladding layer 3, a lower waveguide layer 4, a quantum well active region 5, an upper waveguide layer 6, an upper cladding layer 7, and a contact layer 8, which are sequentially stacked. Among them, the lower cladding layer 3 is used to limit the laser from leaking in the first direction, and the upper cladding layer 7 is used to limit the laser from leaking in the second direction. The band gap width of the lower waveguide layer 4 is between the lower cladding layer 3 and the quantum well active region 5, and the band gap width of the lower waveguide layer 4 is greater than the band gap width of the quantum well active region 5, and the refractive index of the lower waveguide layer 4 is greater than the refractive index of the lower cladding layer 3. The band gap width of the upper waveguide layer 6 is between the upper cladding layer 7 and the quantum well active region 5, and the band gap width of the upper waveguide layer 6 is greater than the band gap width of the quantum well active region 5, and the refractive index of the upper waveguide layer 6 is greater than the refractive index of the upper cladding layer 7. And as Figure 1B shown, the quantum well active region 5, for example, includes one or more quantum well layers 51 and chirped barriers 52 arranged in each other, and the chirped barriers 52 are used to reflect electrons and holes in the quantum well layer to limit the recombination of electrons and holes in the quantum well layer 51 to emit light.

[0040] For example, the first direction can be the direction from the quantum well active region 5 to the substrate 1, and the second direction can be the direction from the quantum well active region 5 to the contact layer 8. The band gap width of each layer material of the quantum well active region 5 to the corresponding cladding layer in the first direction and the second direction increases in turn, and the refractive index decreases in turn, so that the laser generated by the quantum well active region 5 can be localized between the lower waveguide layer 4 and the upper waveguide layer 6, avoiding light leakage, so as to improve the optical gain.

[0041] For example, in order to improve the light limiting effect, the refractive index of the lower waveguide layer 4 can be less than the refractive index of the quantum well active region 5, and the refractive index of the upper waveguide layer 6 can be less than the refractive index of the quantum well active region 5.

[0042] It can be understood that the quantum well active region 5 can be a superposition of one period of quantum well layer 51 and the chirped barrier 52, that is, the combination of electrons and holes can be limited. In order to enhance the optical gain, the quantum well active region 5 can also be an alternating superposition of multiple periods of quantum well layer 51 and the chirped barrier 52. In order to facilitate the preparation and take into account the conductivity of the device, for example, 1-5 periods of quantum well layer 51 and the chirped barrier 52 can be provided.

[0043] Figure 1C The layer structure diagram of the chirped barrier according to the embodiment of the present disclosure is schematically shown.

[0044] According to the embodiment of the present disclosure, as Figure 1C shown, the chirped barrier 52, for example, includes a short period superlattice 521 and a thin layer body material 522. Among them, the number of periods of the short period superlattice 521 is, for example, 3-5, and the thickness of the thin layer body material 522 is, for example, 5-20nm (such as 10nm). The short period superlattice 521, for example, includes indium arsenic layer, aluminum antimony layer and gallium antimony layer which are superimposed on each other in any order. The thin layer body material 522 is, for example, Al 0.25～0.5 GaAsSb.

[0045] For example, the chirped barrier 52 is 3-5 periods of 0.6nm AlSb / 0.75nm InAs / 1.65nm GaSb and 5-10nm AlGaAsSb, wherein the Al component is 0.25-0.5. The superposition order of the short period superlattice 521 can be changed, such as InAs / GaSb / AlSb, or GaSb / AlSb / InAs.

[0046] For example, in order to more effectively confine the carriers in the well layer material, 0.6nm AlSb can be provided in contact with the quantum well layer.

[0047] According to the embodiment of the present disclosure, the thickness and component of the quantum well layer are determined according to the working wavelength of the quantum well laser. Among them, the component of the quantum well layer is, for example, In 0.45-0.5 GaAs 0.18-0.2 Sb. And the thickness of the quantum well layer is, for example, 8-13nm.

[0048] For example, for the quantum well laser, electrons and holes are combined in the quantum well (a type of quantum well) to radiate light, wherein the energy level position of the electron and the energy level position of the hole determine the wavelength of the light. By adjusting the indium component or the arsenic component in InGaAsSb, or adjusting the thickness of the quantum well layer, the working wavelength of the quantum well laser can be finely adjusted.

[0049] Figure 2A comparison diagram of a band diagram of a quantum well active region based on a chirped barrier structure and a band diagram of a conventional quantum well active region is shown.

[0050] According to an embodiment of the present disclosure, as shown in Figure 2 The setting of the chirped barrier beside the quantum well layer does not change the energy level positions of the electrons and holes, so that the addition of the quantum well layer improves the restriction on the electrons and holes without changing the operating wavelength of the quantum well laser.

[0051] According to an embodiment of the present disclosure, the lower cladding layer and the upper cladding layer are AlGaAsSb bulk materials with a high aluminum component, where the aluminum component is greater than or equal to 0.5. The lower waveguide layer and the upper waveguide layer are AlGaAsSb with a low aluminum component, where the aluminum component is less than or equal to 0.3.

[0052] According to an embodiment of the present disclosure, the substrate is lattice-matched to the material of at least one of the buffer layer, the lower cladding layer, the lower waveguide layer, the quantum well active region, the upper waveguide layer, the upper cladding layer, and the contact layer. The material of the substrate is gallium antimony. The substrate, the buffer layer, and the lower cladding layer are N-type doped with gallium tellurium. The upper cladding layer is P-type doped with beryllium. The contact layer is a gallium antimony layer doped with P-type beryllium.

[0053] For example, the GaSb substrate is an N-type doped substrate with a thickness of 500-600 μm (e.g., 550 μm). The GaSb buffer layer is N-type doped with a thickness of about 0.2 μm. The lower cladding layer and the upper cladding layer AlGaAsSb are N-type and P-type doped, respectively, with an aluminum component of 0.5-1 and a thickness of about 2 μm. The lower waveguide layer and the upper waveguide layer AlGaAsSb are undoped with an aluminum component of 0.1-0.3 and a thickness of about 0.3 μm. The contact layer is a GaSb layer doped with P-type with a thickness of about 0.2 μm.

[0054] For example, for a quantum well laser based on GaSb-based materials, lattice matching means that the lattice constant of the epitaxially grown material is consistent with that of the substrate GaSb material (0.61 nm).

[0055] Figure 3 A comparison diagram of the electron and hole reflection energy spectrum of a quantum well active region based on a chirped barrier structure and a conventional quantum well active region is shown.

[0056] According to an embodiment of the present disclosure, based on the transfer matrix algorithm, the carrier reflection spectrum of the quantum well active region based on the chirped barrier structure can be calculated. As shown in Figure 3 The energy corresponding to 100% reflectivity of the electrons and holes is greatly improved, indicating that the chirped barrier structure proposed in the present disclosure can significantly improve the carrier restriction of the quantum well.

[0057] Another aspect of the present disclosure provides a quantum well laser, for example, comprising a quantum well laser epitaxial structure and a plurality of electrodes according to any embodiment of the present disclosure. One of the plurality of electrodes is in contact with the contact layer, and another of the plurality of electrodes is in contact with the substrate. The operating wavelength of the quantum well laser is, for example, 2.6 μm to 2.9 μm.

[0058] For example, the quantum well laser can adopt a ridge waveguide structure, such as a double-channel ridge waveguide structure. In an embodiment of the present disclosure, the depth of the ridge waveguide structure formed by etching can be any position below the upper surface of the upper cladding layer 7 and above the lower surface of the upper waveguide layer 6, and the width of the double-channel ridge waveguide can be 5-35 μm for a narrow strip, and for a single-structure strip waveguide structure, it can also be about 100-200 μm for a wide strip. Those skilled in the art should understand that the specific waveguide structure in this example can be various. The present disclosure can be applied to a quantum well laser of a longer wavelength by providing a chirped barrier structure beside the quantum well layer, which is a high-reflection barrier structure designed for the electron and hole energy levels of the quantum well and has a strong restriction on electrons and holes.

[0059] Figure 4 A growth flow chart of a quantum well laser epitaxial structure according to an embodiment of the present disclosure is schematically shown.

[0060] According to an embodiment of the present disclosure, as shown in Figure 4 The growth method of the quantum well laser epitaxial structure, for example, comprises:

[0061] S410, substrate inspection.

[0062] For example, a piece of 2-inch GaSb (100 surface growth) N-type doped substrate is taken out, and no obvious defects are found by microscope inspection. The atomic force microscope scan shows that the surface roughness is less than 0.5 nm.

[0063] S420, substrate pretreatment.

[0064] For example, the substrate that passes the first step inspection is placed in the sample chamber of a molecular beam epitaxy device, and the sample chamber is degassed at 190°C for 1 hour, and the buffer chamber is degassed at 420°C for 1 hour. Finally, the substrate is sent to the growth chamber for growth.

[0065] S430, high-temperature deoxidization of the substrate.

[0066] For example, the substrate is heated to 640-680°C in the growth chamber and kept for 10-15 minutes to remove the surface oxide of the substrate. Generally, a molecular beam epitaxy device is equipped with a reflection high-energy electron diffraction instrument for in-situ growth monitoring, and the diffraction image can be observed to judge the deoxidization and growth of the substrate surface.

[0067] S440, growing each epitaxial functional layer on the substrate.

[0068] For example, the substrate is cooled to 600-630℃ (e.g. 610℃) to grow a 300nm GaSb buffer layer, and the doping source GaTe is opened. The surface roughness of the obtained GaSb buffer layer is less than 0.1nm, for example. Then, the substrate is heated to 630℃ to perform epitaxial growth of the lower cladding layer and the lower waveguide layer of AlGaAsSb. The substrate temperature is maintained at about 500℃ to perform epitaxial growth of the quantum well active region, the upper waveguide layer, the upper cladding layer and the contact layer in sequence. In order to avoid high-temperature annealing of the quantum well active region, no heating is performed after the growth of the active region. The chirped barrier structure proposed in the present disclosure can greatly improve the confinement of electrons and holes, and the growth window of the structure is large and the growth process is simple.

[0069] In summary, the present disclosure provides a quantum well laser epitaxial structure, which sets a chirped barrier beside the quantum well layer of the quantum well active region in multiple periods, has a high reflection effect on electrons and holes, can confine electrons and holes in the quantum well layer, enhances the interaction between electrons and holes, and thus can improve the optical gain, reduce the threshold current of the device, and improve the characteristic temperature.

[0070] The details of the method embodiments not fully described are similar to the device embodiments. Please refer to the device embodiments, which will not be repeated here.

[0071] It should be understood that the specific order or hierarchy of steps in the processes disclosed is an example of illustrative methods. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes can be rearranged while remaining within the scope of the present disclosure. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

[0072] It should also be noted that the directional terms mentioned in the embodiments, such as "up", "down", "front", "back", "left", "right", etc., are only the directions of the drawings for reference, and are not intended to limit the protection scope of the present disclosure. Throughout the drawings, the same elements are denoted by the same or similar reference numerals. When the understanding of the present disclosure may be confused, the conventional structures or configurations will be omitted. Moreover, the shapes, sizes, and positional relationships of the components in the drawings do not reflect the actual size, proportion, and actual positional relationship.

[0073] In the detailed description above, various features are grouped together in single embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting a necessity to more features than are expressly recited in each claim. Thus, the claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment. It is the intention of the inventor to encompass all such variations and / or permutations of the disclosure within the purview of the appended claims, which follow.

[0074] In addition, the terms "first", "second", and the like, do not denote any order, quantity, combination, or importance, but rather are used to nomenclature different components. Thus, such terms are used herein, merely to identify and distinguish a component from another without necessarily implying any such actual relationship or order between such components. Thus, a feature defined by a first and a second component is not to be interpreted as requiring both components for the feature. The use of the term "a" or "an" herein does not denote a limitation of quantity, but rather denotes the presence of at least one of the referenced item. Thus, such terms are used herein, merely to identify and distinguish a component from another without necessarily implying any such actual relationship or order between such components. Thus, a feature defined by a first and a second component is not to be interpreted as requiring both components for the feature. The use of the term "a" or "an" herein does not denote a limitation of quantity, but rather denotes the presence of at least one of the referenced item. The use of the term "at least one" herein does not denote a limitation of quantity, but rather denotes the presence of at least one of the referenced item. The use of the term "plurality" herein does not denote a limitation of quantity, but rather denotes the presence of at least two of the referenced item. The use of the term "one or more" herein does not denote a limitation of quantity, but rather denotes the presence of at least one of the referenced item. The use of the term "or" in the claims is meant to be interpreted as "and / or" unless explicitly indicated to the contrary. The use of the term "comprises" in the claims is meant to be interpreted as "comprises, but not limited to". The use of the term "comprises" in the description is meant to be interpreted as "comprises, but not limited to".

[0075] It is to be understood that the specific examples described above are merely illustrative of the present disclosure and that numerous modifications, substitutions and changes can be made by those skilled in the art without departing from the spirit and scope of the present disclosure.

Claims

1. A quantum well laser epitaxial structure, characterized in that, include: The substrate, buffer layer, lower cladding layer, lower waveguide layer, quantum well active region, upper waveguide layer, upper cladding layer and contact layer are stacked in sequence. The lower cladding layer is used to restrict laser leakage in the first direction, and the upper cladding layer is used to restrict laser leakage in the second direction. The bandgap width of the lower waveguide layer is between that of the lower cladding layer and the active region of the quantum well, and the bandgap width of the lower waveguide layer is greater than that of the active region of the quantum well, and the refractive index of the lower waveguide layer is greater than that of the lower cladding layer; The bandgap width of the upper waveguide layer is between that of the upper cladding and the active region of the quantum well, and the bandgap width of the upper waveguide layer is greater than that of the active region of the quantum well; the refractive index of the upper waveguide layer is greater than that of the upper cladding; and The active region of the quantum well includes one or more overlapping quantum well layers and a chirped barrier. The chirped barrier is used to reflect electrons and holes in the quantum well layers to limit the recombination of electrons and holes in the quantum well layers to emit light. The chirped barrier comprises a short-period superlattice and a thin-film material; wherein the short-period superlattice has a period number of 3 to 5, and the thin-film material has a thickness of 5 to 20 nm. The short-period superlattice comprises: an indium arsenide layer, an aluminum antimony layer, and a gallium antimony layer stacked in any order; the bulk material of the thin layer is Al. 0.25~0.5 GaAsSb.

2. The quantum well laser epitaxial structure according to claim 1, characterized in that, The thickness and composition of the quantum well layer are determined according to the operating wavelength of the quantum well laser. The quantum well layer is composed of In 0.45-0.5 GaAs 0.18-0.2 Sb; and The thickness of the quantum well layer is 8~13 nm.

3. The quantum well laser epitaxial structure according to claim 2, characterized in that, The aluminum-antimony layer is in contact with the quantum well layer.

4. The quantum well laser epitaxial structure according to claim 1, characterized in that, The lower cladding and the upper cladding are AlGaAsSb bulk materials with a high aluminum content, wherein the aluminum content is greater than or equal to 0.5%.

5. The quantum well laser epitaxial structure according to claim 4, characterized in that, The lower waveguide layer and the upper waveguide layer are AlGaAsSb with low aluminum content, wherein the aluminum content is less than or equal to 0.3%.

6. The quantum well laser epitaxial structure according to claim 1, characterized in that, The substrate is lattice-matched with at least one of the following: the buffer layer, the lower cladding layer, the lower waveguide layer, the quantum well active region, the upper waveguide layer, the upper cladding layer, and the contact layer. The substrate is made of gallium-antimony.

7. The quantum well laser epitaxial structure according to claim 6, characterized in that, The substrate, the buffer layer, and the lower cladding layer are doped with gallium tellurium N-type doping; The upper cladding layer is a beryllium-doped p-type layer; and The contact layer is a P-type beryllium-doped gallium-antimony layer.

8. A quantum well laser, characterized in that, Includes the quantum well laser epitaxial structure and multiple electrodes as described in any one of claims 1 to 7; Wherein, one of the plurality of electrodes is in contact with the contact layer, and another of the plurality of electrodes is in contact with the substrate; and The quantum well laser operates at a wavelength of 2.6 μm to 2.9 μm.

Images