CN117393666B - Super-radiation light-emitting diode - Google Patents

Abstract

This application provides a superradiant light-emitting diode, which includes a substrate, a buffer layer, a first confinement layer, a first waveguide layer, an active layer, a second waveguide layer, a second confinement layer, and an ohmic layer that are stacked from bottom to top. contact layer. The active layer includes: a quantum dot stack layer and a quantum well layer. The quantum dot stack layer includes: n groups of quantum dot units, and each group of the quantum dot units includes a quantum dot single layer, a covering layer and a spacer layer stacked from bottom to top. The material of the quantum well layer is In _x Ga _(1-x) As, where 0.22≤x≤0.38. The position of the luminescence peak of the quantum well layer is between the ground state luminescence peak and the excited state luminescence peak of the quantum dot stack layer. According to the structural arrangement of the active layer in this application, the spectral width can be appropriately broadened and the problem of excessive dip between different luminescence peaks can be eliminated, so that imaging ghosts can be eliminated when superradiant light-emitting diodes are used in OCT imaging systems. .

Description

super radiant light emitting diode

Technical field

The present application relates to the field of semiconductor technology. Specifically, it relates to a superradiant light-emitting diode that can both broaden the spectral luminescence peaks and eliminate the dip between different luminescence peaks. When the superluminescent diode is used in an OCT (optical coherence tomography) imaging system, it can eliminate imaging ghosts.

Background technique

Super luminescent diodes (SLD) are a highly stable light source with high output power and wide spectral range. SLDs have a wider emission spectrum and lower coherence length than semiconductor lasers. Compared with light-emitting diodes, SLDs have higher output power and are widely used in OCT (optical coherence tomography) imaging, fiber optic gyroscopes, fiber optic sensors and other systems.

For single quantum well or uniform multiple quantum well superluminescent diodes, the gain spectrum is relatively narrow, making it difficult to obtain a wide spectrum output; for non-uniform multiple quantum well superluminescent diodes, the output spectrum can be improved to a certain extent. wide, but due to the discontinuity of electronic energy states between different quantum wells, it is difficult to obtain a spectrum with a regular Gaussian shape.

For quantum dot superradiant light-emitting diodes, quantum dots grown through self-organization have certain non-uniformity in size. This non-uniform quantum dot is a favorable factor for the production of wide spectrum devices. Relevant research results show that a collection of quantum dots with a certain size distribution has a wider gain spectrum. The greater the size non-uniformity, the greater the peak drop and the stronger the broadening. At the same time, the size distribution of quantum dots generally satisfies the Gaussian distribution. The ground state and excited state energy levels of quantum dots of different sizes overlap together, making the energy levels of the quantum dot collection approximately continuously distributed, making it easier to form a regular-shaped output spectrum.

Based on the respective characteristics of the above-mentioned quantum dot superluminescent diodes and quantum well superluminescent diodes, superluminescent diodes with mixed active regions of quantum dots and quantum wells are often used in the existing technology to expand the spectral width and increase the output power of the device. . However, although superradiant light-emitting diodes with mixed active regions of quantum dots and quantum wells provided in the existing technology have expanded the spectral width on the surface, they actually have the problem of excessive dip between different luminescence peaks as shown in Figure 1. . Superradiant light-emitting diodes with mixed active regions of quantum dots and quantum wells that have this problem will directly lead to the appearance of imaging ghosts when applied to OCT (optical coherence tomography) imaging systems.

Therefore, there is an urgent need to provide a superradiant light-emitting diode that can solve the problem of excessive dip between different luminescence peaks, so that imaging ghosts can be eliminated when the superradiant light-emitting diode is used in an OCT (optical coherence tomography) imaging system.

Contents of the invention

Since quantum dot SLD or quantum dot + quantum well SLD solutions are used in the existing technology, the purpose is to increase the luminescence peak width of SLD, and the dip problem between different luminescence peaks is not considered. The present application provides a superluminescent diode that can be applied to an OCT (optical coherence tomography) imaging system and can eliminate imaging ghosts.

The technical solutions provided by this application are as follows:

A superradiant light-emitting diode, including a substrate, a buffer layer, a first confinement layer, a first waveguide layer, an active layer, a second waveguide layer, a second confinement layer, and an ohmic contact layer that are stacked from bottom to top;

The active layer includes: a quantum dot stack layer and a quantum well layer;

The quantum dot stack layer includes: n groups of quantum dot units, each group of the quantum dot units includes a quantum dot single layer, a covering layer and a spacer layer stacked from bottom to top;

The material of the quantum well layer is In _x Ga _(1-x) As, where 0.22≤x≤0.38;

The position of the wavelength corresponding to the luminescence peak of the quantum well layer is between the position corresponding to the wavelength of the ground state luminescence peak of the quantum dot stack layer and the position corresponding to the wavelength of the excited state luminescence peak of the quantum dot stack layer.

In one embodiment, the quantum well layer is located between the quantum dot stack layer and the second waveguide layer; the thickness of the quantum well layer is 5-9 nm.

In one embodiment, the material of the quantum dot single layer is InAs, with a thickness of 2.2-3ML; the material of the covering layer is InGaAs, with a thickness of 3-7nm; the material of the spacer layer is GaAs, with a thickness of 30 -40nm; the value range of n is: 4≤n≤8.

In one embodiment, the value of n is: n=6 or 8, and the 6 or 8 groups of quantum dot units include a quantum dot single layer with a first thickness and a quantum dot single layer with a second thickness. layer; in the stacking direction, the quantum dot units of the quantum dot single layer with a first thickness and the quantum dot units of the quantum dot single layer with a second thickness are alternately arranged, the first thickness is not equal to the second thickness, and both the first thickness and the second thickness are within the range of 2.2ML-3ML.

In one embodiment, the value of n is: n=5 or 7, and the thickness of the quantum dot single layer in each of the 5 or 7 groups of quantum dot units is are different, and the thickness of the quantum dot single layer in each group of the quantum dot units arranged from bottom to top in the 5 groups or 7 groups of the quantum dot units increases or decreases by the same amount of change.

In one embodiment, the thickness of the quantum dot single layer in each group of the quantum dot units is 2.7 ML, the thickness of the covering layer is 5 nm, the thickness of the spacer layer is 35 nm, and the n The value is: n=5.

In one embodiment, the quantum well layer is In _0.38 Ga _0.62 As, and the thickness of the quantum well layer is 5 nm.

In one embodiment, the ground state luminescence peak of the quantum dot stack layer is located at 1.3 μm, the excited state luminescence peak of the quantum dot stack layer is located at 1.22 μm, and the luminescence peak of the quantum well layer is located at 1.25 μm.

In one embodiment, the quantum well layer is located between the quantum dot stack layer and the second waveguide layer; the thickness of the quantum well layer is 5-9 nm;

The material of the quantum dot single layer is InAs, with a thickness of 2.2-3ML; the material of the covering layer is InGaAs, with a thickness of 3-7nm; the material of the spacer layer is GaAs, with a thickness of 30-40nm; the n The value range of is: 5≤n≤9.

In one embodiment, the thickness of the quantum dot single layer is 2.3ML, the thickness of the covering layer is 4nm, the thickness of the spacer layer is 40nm, and the value range of n is: n=5.

In one embodiment, the quantum well layer is In _0.35 Ga _0.65 As, and the thickness of the quantum well layer is 5 nm.

In one embodiment, the ground state luminescence peak of the quantum dot stack layer is located at 1.25 μm, the excited state luminescence peak of the quantum dot stack layer is located at 1.1 μm, and the luminescence peak of the quantum well layer is located at 1.18 μm.

The solution provided by this application has the following beneficial effects:

1. The material of the quantum well layer is In _x Ga _(1-x) As, where 0.22≤x≤0.38. The position of the luminescence peak of the quantum well layer is between the ground state luminescence peak and the excited state luminescence peak of the quantum dot stack layer. According to the structural arrangement of the active layer in this application, the quantum well layer can be used to compensate for the dip between the quantum dot's ground state luminescence peak and the excited state luminescence peak based on the current broad luminescence peak of the quantum dot's ground state + excited state. The solution provided by this application solves the problem of traditional quantum dot superradiant light-emitting diodes that cause the spectrum dip to be too deep due to the ground state and excited state light emission, affecting the OCT imaging effect.

2. The quantum well layer is located between the quantum dot stack layer and the second waveguide layer. It can be understood that: the quantum well layer is located above the quantum dot stack layer, which can be beneficial to the balance of the luminous efficiency of the quantum well layer and the quantum dot stack layer. Because the gain of the quantum dot stack layer is easier to gain saturation, the injected carriers can be effectively distributed in the quantum well layer and the quantum dot stack layer. In this embodiment, locating the quantum well layer above the quantum dot stack layer can ensure that the injected carriers are not easily clamped by the quantum well layer, thereby making the luminous efficiency of the superluminescent diode more balanced.

3. The special structural design of the quantum dot stack layer, such as the design of the chirped quantum dot stack layer structure, can make full use of the wide spectrum characteristics of quantum dots and better realize the broadening of the spectrum. Coupled with the special design of the quantum well layer, This in turn can avoid the dip problem of quantum dot luminescence peaks and achieve wider spectral output without dip.

In order to make the above-mentioned objects, features and advantages of the present application more obvious and understandable, preferred embodiments are given below and described in detail with reference to the attached drawings.

Description of drawings

In order to explain the technical solutions of the embodiments of the present application more clearly, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and therefore do not illustrate the technical solutions of the embodiments of the present application. It should be regarded as a limitation of the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a spectrum diagram of a superluminescent diode provided in the prior art;

Figure 2 is a schematic structural diagram of a superradiant light-emitting diode provided by an embodiment of the present application;

Figure 3 is a spectrum diagram of a superluminescent diode provided by an embodiment of the present application;

FIG. 4 is a schematic diagram of the spectral effects of superradiant light-emitting diodes in various embodiments of the present application.

Reference signs:

Superradiant LED 100:

Substrate 10, buffer layer 20, first confinement layer 30, first waveguide layer 40, active layer 50, second waveguide layer 60, second confinement layer 70, ohmic contact layer 80, first electrode 91, second electrode 92;

Quantum dot stack layer 51, quantum well layer 52;

Quantum dot unit 510, quantum dot single layer 511, covering layer 512, and spacer layer 513.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations. Accordingly, the following detailed description of the embodiments of the application provided in the appended drawings is not intended to limit the scope of the claimed application, but rather to represent selected embodiments of the application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without any creative work shall fall within the scope of protection of this application.

It should be noted that similar reference numerals and letters represent similar items in the following figures, therefore, once an item is defined in one figure, it does not need further definition and explanation in subsequent figures. Meanwhile, in the description of the present application, the terms "first", "second", etc. are only used to differentiate the description and cannot be understood as indicating or implying relative importance.

As shown in Figure 1, there is an obvious dip between different luminescence peaks in the spectrum of the existing superluminescent diode (here dip can be understood as the luminescence valley that exists between the two luminescence peaks). Therefore, in order to solve the above defects, the technical solution of the present application is proposed. The technical solution of the present application will be described in detail below.

As shown in FIG. 2 , the present application provides a superluminescent diode 100 including a substrate 10 , a buffer layer 20 , a first confinement layer 30 , a first waveguide layer 40 , an active layer 50 , and a substrate 10 stacked from bottom to top. The second waveguide layer 60, the second confinement layer 70, the ohmic contact layer 80, and the first electrode 91 and the second electrode 92 provided at both ends.

The substrate 10 may be a Si-doped n-GaAs (100) substrate. The buffer layer 20 may be an n-GaAs buffer layer, and its thickness may be set to 300 nm. The first confinement layer 30 may be set to n-Al _0.4 Ga _0.6 As, and its thickness may be set to 1400 nm. The first waveguide layer 40 may be set to i-GaAs, and its thickness may be set to 70 nm. The second waveguide layer 60 may be configured as i-GaAs, and its thickness may be configured as 40 nm. The second confinement layer 70 may be set to p-Al _0.4 Ga _0.6 As, and its thickness may be set to 1400 nm. The ohmic contact layer 80 may be set to GaAs, and its thickness may be set to 200 nm. The first electrode 91 and the second electrode 92 provided at both ends may be provided as gold electrodes or silver electrodes.

The active layer 50 includes: a quantum dot stack layer 51 and a quantum well layer 52 .

The quantum dot stack layer 51 includes: n groups of quantum dot units 510. Each group of the quantum dot units 510 includes a quantum dot single layer 511, a covering layer 512 and a spacer layer 513 stacked from bottom to top.

The material of the quantum well layer 52 is In _x Ga _(1-x) As, where 0.22≤x≤0.38.

The position of the luminescence peak of the quantum well layer 52 is between the ground state luminescence peak and the excited state luminescence peak of the quantum dot stack layer 51 .

In this embodiment, a mixed active layer structure of quantum dots and quantum wells is used to form the superluminescent diode. _{The quantum} well layer 52 is made of In between the excited state luminescence peaks. According to the structural setting of the active layer in this embodiment, based on the current broad luminescence peak of the quantum dot's ground state + excited state, the quantum well layer can be used to compensate for the dip between the quantum dot's ground state luminescence peak and the excited state luminescence peak. The luminescence peak of the superluminescent diode 100 is adjusted to a Gaussian-like distribution (the curve represented by quantum wells + quantum dots in Figure 3 is a Gaussian-like distribution after broadening the luminescence peak). The solution provided by this application solves the problem of traditional quantum dot superradiant light-emitting diodes that cause the spectrum dip to be too deep due to the ground state and excited state light emission, affecting the OCT imaging effect.

In one embodiment, the quantum dot single layer 511 is made of InAs with a thickness of 2.2-3 ML; the covering layer 512 is made of InGaAs with a thickness of 3-7 nm, such as 4 nm or 4.5 nm. The spacer layer 513 is made of GaAs and has a thickness of 30-40 nm, such as 32 nm, 35 nm, 38 nm or 40 nm. The value range of n is: 5≤n≤8, for example, n can be 5, 6, 7 or 8.

In one embodiment, the quantum well layer 52 is located between the quantum dot stack layer 51 and the second waveguide layer 60 . That is, the quantum well layer 52 is located above the quantum dot stack layer 51 , and the quantum well layer 52 is disposed closer to the second waveguide layer 60 . The thickness of the quantum well layer 52 is 5-9 nm, for example, it can be 5 nm, 6.5 nm, 7 nm, 8 nm, 8.5 nm or 9 nm.

In this embodiment, the quantum well layer 52 is located above the quantum dot stack layer 51, which can be beneficial to the balance of the luminous efficiency of the quantum well layer 52 and the quantum dot stack layer 51. Because the gain of the quantum dot stack layer 51 is easier to gain saturation, the injected carriers can be effectively distributed in the quantum well layer 52 and the quantum dot stack layer 51 . In this embodiment, locating the quantum well layer 52 above the quantum dot stack layer 51 can ensure that the injected carriers are not easily clamped by the quantum well layer, thereby making the luminous efficiency of the superluminescent diode more balanced.

In one embodiment, an InGaAs quantum well layer 52 with a thickness of 6 nm and an In composition of 0.38 may be provided, and the quantum well layer 52 is located above the quantum dot stack layer 51 . According to the structural arrangement of the active layer 50 in this embodiment, on the one hand, the active layer 50 includes the quantum dot stack layer 51 and the quantum well layer 52, which can ensure a wide luminescence peak. Below, an InGaAs quantum well layer 52 with a thickness of 6 nm and an In composition of 0.38 is used to compensate the luminescence peak dip between the quantum dot's ground state luminescence peak and the excited state luminescence peak, and the luminescence peak of the superluminescent diode 100 is adjusted to be Gaussian-like. Distribution, solves the problem of traditional quantum dot superluminescent diodes that cause the spectrum dip to be too deep due to ground state and excited state emission, affecting the OCT imaging effect. On the other hand, the quantum well layer 52 is located above the quantum dot stack layer, which is more conducive to balancing the luminous efficiency of the failed quantum dots and the quantum well layer in the quantum dot stack layer.

In one embodiment, the thickness of the quantum dot single layer 511 is 2.7ML, the thickness of the covering layer 512 is 5nm, the thickness of the spacer layer 513 is 35nm, and the value range of n is: n= 5. The quantum well layer 52 is In _0.38 Ga _0.62 As, and the thickness of the quantum well layer 52 is 5 nm. In this embodiment, the ground state luminescence peak of the quantum dot stack layer is located at 1.3 μm, the excited state luminescence peak of the quantum dot stack layer is located at 1.22 μm, and the luminescence peak of the quantum well layer is located at 1.25 μm.

In another embodiment, the thickness of the quantum dot single layer 511 is 2.3ML, the thickness of the covering layer 512 is 4nm, the thickness of the spacer layer 513 is 40nm, and the value range of n is: n =5, the quantum well layer 52 is In _0.35 Ga _0.65 As, and the thickness of the quantum well layer 52 is 5 nm. In this embodiment, the ground state luminescence peak of the quantum dot stack layer 51 is located at 1.25 μm, the excited state luminescence peak of the quantum dot stack layer 51 is located at 1.1 μm, and the luminescence peak of the quantum well layer 52 is located at 1.18 μm.

Four different embodiments are listed below, all of which can appropriately broaden the spectral width while eliminating the problem of excessive dip between different luminescence peaks, and adjust the luminescence peak of the superradiant light-emitting diode 100 to a Gaussian-like distribution, so as to This enables the superluminescent diode 100 to eliminate imaging ghosts when used in an OCT imaging system.

First embodiment:

The superluminescent diode 100 is arranged as shown in FIG. 2 and includes a substrate 10, a buffer layer 20, a first confinement layer 30, a first waveguide layer 40, an active layer 50, and a second waveguide stacked from bottom to top. layer 60, the second confinement layer 70, the ohmic contact layer 80, and the first electrode 91 and the second electrode 92 provided at both ends.

The active layer 50 includes: a quantum dot stack layer 51 and a quantum well layer 52 . The quantum well layer 52 is located between the quantum dot stack layer 51 and the second waveguide layer 60 .

The quantum dot stack layer 51 includes: 5 groups of quantum dot units 510. Each group of the quantum dot units 510 includes a 2.7ML InAs quantum dot single layer 511, a 5nm InGaAs covering layer 512 and a 2.7ML InAs quantum dot single layer 511 stacked from bottom to top. 35nm GaAs spacer layer 513.

The quantum well layer 52 is made of In _0.38 Ga _0.62 As and has a thickness of 5 nm. The quantum well layer 52 is located above the quantum dot stack layer 51, which is more conducive to balancing the luminous efficiency of failed quantum dots and quantum wells. The position of the luminescence peak (1.25 μm) of the quantum well layer 52 is between the ground state luminescence peak (1.3 μm) and the excited state luminescence peak (1.22 μm) of the quantum dot stack layer 51 .

Second embodiment:

The superluminescent diode 100 is arranged as shown in FIG. 2 and includes a substrate 10, a buffer layer 20, a first confinement layer 30, a first waveguide layer 40, an active layer 50, and a second waveguide stacked from bottom to top. layer 60, the second confinement layer 70, the ohmic contact layer 80, and the first electrode 91 and the second electrode 92 provided at both ends.

The active layer 50 includes: a quantum dot stack layer 51 and a quantum well layer 52 . The quantum well layer 52 is located between the quantum dot stack layer 51 and the second waveguide layer 60 .

The quantum dot stack layer 51 includes: 6 groups of quantum dot units 510. Each group of the quantum dot units 510 includes an InAs quantum dot single layer 511, a 4 nm InGaAs covering layer 512 and a 35 nm GaAs stacked from bottom to top. Spacer layer 513. Among them, the thickness of the InAs quantum dot single layer 511 in a single group of quantum dot units 510 among the six groups of quantum dot units 510 is 2.4ML. The thickness of the InAs quantum dot single layer 511 in the plural groups of quantum dot units 510 in the six groups of quantum dot units 510 is 3ML. The quantum dot stacked layer 51 adopts the design of the chirped quantum dot stacked layer structure, which can fully utilize the wide spectrum characteristics of quantum dots and better realize the broadening of the spectrum. Coupled with the special design of the quantum well layer, it can avoid Dip problem of quantum dot luminescence peak, achieving wider spectrum output without dip.

The quantum well layer 52 is made of In _0.38 Ga _0.62 As and has a thickness of 5 nm. The position of the luminescence peak (1.25 μm) of the quantum well layer 52 is between the ground state luminescence peak (1.3 μm) and the excited state luminescence peak (1.22 μm) of the quantum dot stack layer 51 .

As shown in FIG. 4 , in the above-mentioned first and second embodiments, although the partial structure, material or thickness of the quantum dot stack layer 51 undergoes slight changes, the ground state luminescence of the quantum dot stack layer 51 still remains. The peaks are all located at 1.3 μm, the excited state luminescence peaks of the quantum dot stack layer 51 are all located at 1.22 μm, and the luminescence peaks of the quantum well layer 52 are all located at 1.25 μm. Both the first and second embodiments described above can eliminate the dip between the quantum dot's ground state luminescence peak and the first excited state luminescence peak, and adjust the luminescence peak of the superluminescent diode 100 to a Gaussian-like distribution.

Third embodiment:

The superluminescent diode 100 is arranged as shown in FIG. 2 and includes a substrate 10, a buffer layer 20, a first confinement layer 30, a first waveguide layer 40, an active layer 50, and a second waveguide stacked from bottom to top. layer 60, the second confinement layer 70, the ohmic contact layer 80, and the first electrode 91 and the second electrode 92 provided at both ends.

The active layer 50 includes: a quantum dot stack layer 51 and a quantum well layer 52 . The quantum well layer 52 is located between the quantum dot stack layer 51 and the second waveguide layer 60 .

The quantum dot stack layer 51 includes: 5 groups of quantum dot units 510. Each group of the quantum dot units 510 includes an InAs quantum dot single layer 511, a 4 nm InGaAs covering layer 512 and a 35 nm GaAs stacked from bottom to top. Spacer layer 513. Among them, the thicknesses of the InAs quantum dot single layer 511 from bottom to top in the five groups of quantum dot units 510 are 2.2ML, 2.3ML, 2.35ML, 2.4ML, and 2.45ML respectively. The quantum dot stacked layer 51 adopts the design of the chirped quantum dot stacked layer structure, which can fully utilize the wide spectrum characteristics of quantum dots and better realize the broadening of the spectrum. Coupled with the special design of the quantum well layer, it can avoid Dip problem of quantum dot luminescence peak, achieving wider spectrum output without dip.

The material of the quantum well layer 52 is In _0.35 Ga _0.65 As, and the thickness is 5 nm. The quantum well layer 52 is located above the quantum dot stack layer 51, which is more conducive to balancing the luminous efficiency of failed quantum dots and quantum wells. The position of the luminescence peak (1.18 μm) of the quantum well layer 52 is between the ground state luminescence peak (1.25 μm) and the excited state luminescence peak (1.1 μm) of the quantum dot stack layer 51 .

Fourth embodiment:

The superluminescent diode 100 is arranged as shown in FIG. 2 and includes a substrate 10, a buffer layer 20, a first confinement layer 30, a first waveguide layer 40, an active layer 50, and a second waveguide stacked from bottom to top. layer 60, the second confinement layer 70, the ohmic contact layer 80, and the first electrode 91 and the second electrode 92 provided at both ends.

The active layer 50 includes: a quantum dot stack layer 51 and a quantum well layer 52 . The quantum well layer 52 is located between the quantum dot stack layer 51 and the second waveguide layer 60 .

The quantum dot stack layer 51 includes: 6 groups of quantum dot units 510. Each group of the quantum dot units 510 includes an InAs quantum dot single layer 511, a 6 nm InGaAs covering layer 512 and a 40 nm GaAs stacked from bottom to top. Spacer layer 513. Among them, the thicknesses of the InAs quantum dot single layer 511 from bottom to top in the six groups of quantum dot units 510 are 2.3ML, 2.3ML, 2.4ML, 2.4ML, 2.5ML, and 2.5ML respectively. The quantum dot stacked layer 51 adopts the design of the chirped quantum dot stacked layer structure, which can fully utilize the wide spectrum characteristics of quantum dots and better realize the broadening of the spectrum. Coupled with the special design of the quantum well layer, it can avoid Dip problem of quantum dot luminescence peak, achieving wider spectrum output without dip.

The material of the quantum well layer 52 is In _0.35 Ga _0.65 As, and the thickness is 6 nm. The position of the luminescence peak (1.18 μm) of the quantum well layer 52 is between the ground state luminescence peak (1.25 μm) and the excited state luminescence peak (1.1 μm) of the quantum dot stack layer 51 .

As shown in FIG. 4 , in the above third and fourth embodiments, although the partial structure, material or thickness of the quantum dot stack layer 51 undergoes slight changes, the ground state luminescence of the quantum dot stack layer 51 still remains. The peaks are all located at 1.25 μm, the excited state luminescence peaks of the quantum dot stack layer 51 are all located at 1.1 μm, and the luminescence peaks of the quantum well layer 52 are all located at 1.18 μm. Both the third embodiment and the fourth embodiment described above can eliminate the dip between the quantum dot's ground state luminescence peak and the first excited state luminescence peak, and adjust the luminescence peak of the superluminescent diode 100 to a Gaussian-like distribution.

The above descriptions are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included in the protection scope of this application. It should be noted that similar reference numerals and letters represent similar items in the following figures, therefore, once an item is defined in one figure, it does not need further definition and explanation in subsequent figures.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application. should be covered by the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims (9)

1. A superradiant light-emitting diode, comprising a substrate, a buffer layer, a first confinement layer, a first waveguide layer, an active layer, a second waveguide layer, a second confinement layer, and an ohmic contact layer that are stacked from bottom to top. ; It is characterized by, The active layer includes: a quantum dot stack layer and a quantum well layer; The quantum dot stack layer includes: n groups of quantum dot units. Each group of the quantum dot units includes a quantum dot single layer, a covering layer and a spacer layer stacked from bottom to top. The material of the quantum dot single layer is InAs, with a thickness of 2.2-3ML; the material of the covering layer is InGaAs, with a thickness of 3-7nm; the material of the spacer layer is GaAs, with a thickness of 30-40nm, and the value range of n is: 5≤n ≤8; The material of the quantum well layer is In _x Ga _(1-x) As, where 0.22≤x≤0.38; The quantum well layer is located between the quantum dot stack layer and the second waveguide layer; the thickness of the quantum well layer is 5-9 nm; The position of the wavelength corresponding to the luminescence peak of the quantum well layer is between the position corresponding to the wavelength of the ground state luminescence peak of the quantum dot stack layer and the position corresponding to the wavelength of the excited state luminescence peak of the quantum dot stack layer. 2. The superluminescent diode according to claim 1, wherein the value of n is: n=6 or 8, and the 6 or 8 groups of quantum dot units include quantum dots with a first thickness. A single layer of dots and a single layer of quantum dots with a second thickness; in the stacking direction, the quantum dot units of the single layer of quantum dots with a first thickness and all the units of the single layer of quantum dots with a second thickness The quantum dot units are arranged alternately, the first thickness is not equal to the second thickness, and both the first thickness and the second thickness are within the range of 2.2ML-3ML. 3. The superradiant light-emitting diode according to claim 1, characterized in that the value of n is: n=5 or 7, and each group of the quantum dot units in 5 groups or 7 groups The thickness of the quantum dot single layer in the dot unit is different, and the quantum dot single layer in each group of the quantum dot unit arranged from bottom to top in 5 groups or 7 groups of quantum dot units The thickness increases or decreases by the same amount. 4. The superluminescent diode according to claim 1, wherein the thickness of the quantum dot single layer in each group of the quantum dot units is 2.7ML, and the thickness of the covering layer is 5nm, The thickness of the spacer layer is 35 nm, and the value of n is: n=5. 5. The superluminescent diode according to claim 4, wherein the quantum well layer is In _0.38 Ga _0.62 As, and the thickness of the quantum well layer is 5 nm. 6. The superluminescent diode according to any one of claims 1 to 5, characterized in that the ground state luminescence peak of the quantum dot stack layer is located at 1.3 μm, and the excited state luminescence peak of the quantum dot stack layer is located at 1.3 μm. 1.22 μm, and the luminescence peak of the quantum well layer is located at 1.25 μm. 7. The superluminescent diode according to claim 1, wherein the thickness of the quantum dot single layer is 2.3ML, the thickness of the covering layer is 4nm, and the thickness of the spacer layer is 40nm. 8. The superluminescent diode according to claim 7, wherein the quantum well layer is In _0.35 Ga _0.65 As, and the thickness of the quantum well layer is 5 nm. 9. The superluminescent diode according to claim 7 or 8, characterized in that the ground state luminescence peak of the quantum dot stack layer is located at 1.25 μm, and the excited state luminescence peak of the quantum dot stack layer is located at 1.1 μm, so The luminescence peak of the quantum well layer is located at 1.18 μm.