Multi-wavelength light emitting diode and light emitting module

Abstract

The invention relates to the technical field of semiconductor devices, in particular to a multi-wavelength light emitting diode and a light emitting module. The multi-wavelength light-emitting diode comprises a multi-quantum well layer, wherein the multi-quantum well layer comprises at least m groups of light-emitting regions for generating light with different wavelengths along a first direction; a first well layer, closest to a first light-emitting region of the N-type semiconductor layer, in the multi-quantum well layer has the highest In concentration or the minimum forbidden bandwidth; the second light-emitting region is arranged on the first light-emitting region, and the forbidden bandwidth of the second well layer is greater than or equal to that of the first well layer; the third light-emitting region is arranged on the second light-emitting region, and the forbidden bandwidth of the third well layer is larger than that of the second well layer; a buffer region is arranged in the multi-quantum well layer and is arranged between the first light-emitting region and the second light-emitting region or in the second light-emitting region; the forbidden bandwidth of the buffer region is greater than that of the second well layer. According to the light-emitting diode, by arranging the buffer area and matching with parameter setting of other light-emitting areas, lattice mismatch can be relieved, the crystal quality of the light-emitting areas can be improved, and the light-emitting efficiency can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a multi-wavelength light emitting diode and a light emitting module. Background Art

[0002] Light Emitting Diode (LED) is a light-emitting device that can efficiently convert electrical energy into light energy and is widely used in lighting, display and other fields. With the development of technology, the demand for full spectrum in white light illumination has increased. Integrating multiple wavelengths on the same chip can effectively reduce the manufacturing cost of full spectrum devices. In addition, in the production of Micro Light Emitting Diode (Micro LED), mass transfer technology is one of the main technical bottlenecks in its development. Integrating multiple wavelengths on the same chip can reduce the technical pressure of mass transfer and reduce the difficulty of producing Micro LED products.

[0003] The existing epitaxial technology of multi-wavelength LEDs grows multi-wavelength quantum wells in the active region one after another. Because the band gaps of light-emitting regions of different wavelengths have different acceptance capacities for carriers, the active region generally presents a growth order from narrow to wide in the band gap of the well region along the direction from the N side to the P side. Since the light-emitting region with a narrower band gap grows first, and the light-emitting region with a narrower band gap usually has a higher In content or a thicker well layer, this will cause a larger lattice mismatch between the light-emitting region and the layers before and after it, and then generate a larger piezoelectric polarization field, affecting the crystal quality and luminous efficiency of the subsequent light-emitting region.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] An object of the present invention is to provide a multi-wavelength light emitting diode that can balance the carrier capture capability of each well layer and buffer the lattice mismatch caused by the band gap difference of each well layer to improve the light emitting efficiency.

[0006] Another object of the present invention is to provide a light emitting module.

[0007] In order to achieve the above-mentioned object of the present invention, the present invention provides a multi-wavelength light-emitting diode, comprising: a multi-quantum well layer disposed between an N-type semiconductor layer and a P-type semiconductor layer; A direction from the N-type semiconductor layer to the P-type semiconductor layer is defined as a first direction, the multi-quantum well layer includes m groups of light-emitting regions that generate light of different wavelengths along the first direction, each light-emitting region includes at least one well layer and one barrier layer, wherein m≥3; The first well layer of the first light-emitting region closest to the N-type semiconductor layer in the multi-quantum well layer has the highest In concentration or the smallest bandgap width; the second light-emitting region including the second well layer and the second barrier layer is arranged on the first light-emitting region, wherein the bandgap width of the second well layer is greater than or equal to the first well layer; the third light-emitting region including the third well layer and the third barrier layer is arranged on the second light-emitting region, wherein the bandgap width of the third well layer is greater than that of the second well layer; The multi-quantum well layer also includes a buffer zone; the buffer zone is arranged between the first light-emitting zone and the second light-emitting zone, or the buffer zone is arranged in the second light-emitting zone; the bandgap width of the buffer zone is greater than that of the second well layer.

[0008] In a specific embodiment of the present invention, the buffer zone includes at least one of an undoped GaN single layer, a doped GaN single layer and a superlattice structure layer; and the doping element includes at least one of In, Si, Al and Mg.

[0009] Furthermore, the buffer zone includes an InGaN single layer and a Si-doped GaN single layer, the In concentration in the InGaN single layer is less than or equal to the In concentration in the second well layer; the In concentration in the InGaN single layer is greater than or equal to the In concentration in the third well layer.

[0010] In a specific embodiment of the present invention, the superlattice structure layer has a period number of 1 to 50. Further, the superlattice structure layer includes at least one of an InGaN / GaN superlattice structure layer, an InGaN / AlGaN superlattice structure layer, an InAlGaN / GaN superlattice structure layer and an InAlGaN / InGaN superlattice structure layer.

[0011] In a specific embodiment of the present invention, the wavelength peaks generated by each light-emitting region of the multi-quantum well layer gradually decrease in the first direction. Furthermore, the difference Δλ between the wavelength peaks generated by each adjacent light-emitting region is ≤25nm.

[0012] In a specific embodiment of the present invention, the bandgap width of the well layer in the first light-emitting region to the bandgap width of the well layer in the mth light-emitting region gradually increases in the first direction.

[0013] In a specific embodiment of the present invention, the In concentration in the well layer of the first light-emitting region to the In concentration in the well layer of the mth light-emitting region gradually decreases in the first direction.

[0014] In a specific embodiment of the present invention, the spectrum of the multi-quantum well layer has at least three peaks between 420 and 480 nm, including a first peak between 435 and 447 nm, a second peak between 445 and 457 nm, and a third peak between 460 and 473 nm; Among them, the peak intensity of the third peak is the smallest, at least one of the first peak or the second peak has the largest peak intensity, and the ratio of the peak intensity of the third peak to the maximum peak intensity is 0.4 to 0.6; the ratio of the peak intensity of the first peak to the peak intensity of the second peak is 0.8 to 1 or the ratio of the peak intensity of the second peak to the peak intensity of the first peak is 0.8 to 1.

[0015] In a specific embodiment of the present invention, one well layer and one barrier layer in each light-emitting zone is defined as one period, the number of periods in the first light-emitting zone is 1 to 5, the number of periods in the second light-emitting zone is 1 to 5, and the number of periods in the third light-emitting zone is 1 to 15.

[0016] In a specific embodiment of the present invention, the multi-quantum well layer further includes an m+1th light-emitting region close to the P-type semiconductor layer, and a light-emitting region adjacent to the m+1th light-emitting region and away from the P-type semiconductor layer is the mth light-emitting region, and the m+1th light-emitting region satisfies at least one of the following conditions: (1) The In concentration of the well layer of the m+1th light-emitting region is greater than the In concentration of the well layer of the mth light-emitting region; (2) The bandgap width of the well layer of the m+1th light-emitting region is smaller than the bandgap width of the well layer of the mth light-emitting region.

[0017] In a specific embodiment of the present invention, the multi-quantum well layer includes five groups of light-emitting regions, which are respectively a first light-emitting region, a second light-emitting region, a third light-emitting region, a fourth light-emitting region and a fifth light-emitting region along the first direction; and at least one of the following conditions is satisfied: (1) The thickness of a single well layer in the first light-emitting region, the second light-emitting region, the third light-emitting region, the fourth light-emitting region, and the fifth light-emitting region are d 1 d 2 d 3 d 4 and d 5 , each thickness satisfies: d 2 ≤d 3 ≤d 4 ≤d1,d 4 With d 5 Satisfaction:d 4 >d 5 or 4 <d 5 or 4 =d 5 ; (2) The concentrations of In in the single well layers of the first light-emitting region, the second light-emitting region, the third light-emitting region, the fourth light-emitting region, and the fifth light-emitting region are respectively X 1 , X 2 , X 3 , X 4 and X 5 , each concentration satisfies: X 1 >X 2 >X 3 >X 4 , X 4 With X 5 Satisfaction: X 4 >X 5 or X 4 <X 5 or X 4 =X 5 ; (3) The bandgap widths of the single well layers in the first light-emitting region, the second light-emitting region, the third light-emitting region, the fourth light-emitting region, and the fifth light-emitting region are Eg respectively. 1 , Eg 2 , Eg 3 , Eg 4 and Eg 5 , each bandgap width satisfies: Eg 1 ≤Eg 2 <Eg 3 <Eg 4 , Eg 4 With Eg 5 Satisfaction: Eg 4 >Eg 5 Or Eg 4 <Eg 5 Or Eg 4 =Eg 5 ; (4) The number of periodic structures of well layers and barrier layers in the first light-emitting region, the second light-emitting region, the third light-emitting region, the fourth light-emitting region, and the fifth light-emitting region is Y respectively. 1 , Y 2 , Y 3 , Y 4 and Y 5 , the number of periodic structures satisfies: Y 1 ≤Y 2 ≤Y 3 ≤Y 4 , Y 4 ≥Y 5 ; (5) The wavelength peaks generated by the first light-emitting area, the second light-emitting area, the third light-emitting area, the fourth light-emitting area and the fifth light-emitting area are λ 1 , 2 , 3, 4 and λ 5 , each wavelength peak satisfies: λ 1 >λ 2 >λ 3 >λ 4 ,λ 5 >λ 4 .

[0018] Another aspect of the present invention provides a light-emitting module, comprising any one of the above-mentioned light-emitting diodes and a wavelength conversion unit; the light generated by the light-emitting diode passes through the wavelength conversion unit and then is mixed to generate white light.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) The light-emitting diode of the present invention can better balance the difference in carrier capture ability of each well layer due to different band gaps of each light-emitting zone by setting a buffer zone between the first light-emitting zone and the second light-emitting zone or setting a buffer zone in the second light-emitting zone, and can alleviate the lattice mismatch caused by the difference in band gaps of each light-emitting zone, thereby improving the crystal quality of the light-emitting zone; (2) By using the light-emitting diode of the present invention in combination with a wavelength conversion material, a light-emitting module with high light-emitting efficiency can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of the epitaxial structure of a light emitting diode provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a multi-quantum well layer provided by an embodiment of the present invention; Figure 3 Another schematic diagram of the structure of a multi-quantum well layer provided by an embodiment of the present invention; Figure 4 A schematic diagram of the structure of a light emitting diode provided in an embodiment of the present invention; Figure 5 A spectrum distribution diagram of the light emitting diode of the present invention; Figure 6 Another spectrum distribution diagram of the light emitting diode of the present invention; Figure 7 A schematic diagram of the bandgap structure of a multi-quantum well layer provided in Example 1 of the present invention; Figure 8 A schematic diagram of the bandgap structure of a multi-quantum well layer provided in Example 2 of the present invention; Fig. 9 A schematic diagram of the bandgap structure of a multi-quantum well layer provided in Example 3 of the present invention; Fig.10 A schematic diagram of the bandgap structure of a multi-quantum well layer provided in Example 4 of the present invention; Fig.11 Schematic diagram of the bandgap structure of the multi-quantum well layer provided in Example 5 of the present invention.

[0022] Reference numerals: 10-substrate; 20-buffer layer; 30-N-type semiconductor layer; 40-stress release layer; 50-multi-quantum well layer; 60-P-type semiconductor layer; 51-first light-emitting region; 52-second light-emitting region; 53-m-th light-emitting region; 500-buffer layer; 55-m+1-th light-emitting region; 51a-well layer of the first light-emitting region; 51b-barrier layer of the first light-emitting region; 52a-well layer of the second light-emitting region; 52b-barrier layer of the second light-emitting region; 53a-well layer of the m-th light-emitting region; 53b-barrier layer of the m-th light-emitting region; 55 a-well layer of the m+1th light-emitting zone; 55b-barrier layer of the m+1th light-emitting zone; 511-first well layer; 512-first barrier layer; 521-second well layer; 522-second barrier layer; 531-third well layer; 532-third barrier layer; 541-fourth well layer; 542-fourth barrier layer; 551-fifth well layer; 552-fifth barrier layer; P12, P22-second wave peak; P11, P21-first wave peak; P13, P23-third wave peak; 501-InGaN layer; 502-GaN layer. DETAILED DESCRIPTION

[0023] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0024] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0025] In the existing epitaxial technology of multi-wavelength LEDs, multi-wavelength quantum wells are grown in the active region one after another. Since the band gaps of the light-emitting regions of different wavelengths are different, and different band gaps have different carrier acceptance capabilities, the band gap of the well region generally grows from narrow to wide from the N-type semiconductor side to the P-type semiconductor layer side. The light-emitting region with a narrow band gap either corresponds to a high In content or a thick well layer, which will cause a large lattice mismatch between the light-emitting region and the layers before and after it, affecting the crystal quality and luminous efficiency.

[0026] Based on this, the present invention provides a multi-wavelength light emitting diode, Figure 1 A schematic diagram of a light-emitting diode epitaxial structure provided in an embodiment of the present invention, wherein the light-emitting diode epitaxial structure comprises: A substrate 10, and a buffer layer 20, an N-type semiconductor layer 30, a stress release layer 40, a multi-quantum well layer 50 and a P-type semiconductor layer 60 are sequentially arranged on the substrate 10. The multi-quantum well layer includes m groups of light-emitting regions that can generate light of different wavelengths, m≥3, such as m can be a natural number such as 3, 4, 5, 6, etc., but is not limited thereto.

[0027] Figure 2 A schematic diagram of the structure of a multi-quantum well layer provided in an embodiment of the present invention. The direction from the N-type semiconductor layer 30 to the P-type semiconductor layer 60 is defined as a first direction, and the multi-quantum well layer includes m groups of light-emitting regions that generate light of different wavelengths along the first direction, including a first light-emitting region 51 closest to the N-type semiconductor layer 30, a second light-emitting region 52 adjacent to the first light-emitting region 51, an mth light-emitting region 53 closest to the P-type semiconductor layer 60, and optionally one or more light-emitting regions between the second light-emitting region 52 and the mth light-emitting region 53 (not shown in the figure, represented by ...).

[0028] Furthermore, each light-emitting zone includes at least one periodic structure of alternately stacked well layers and barrier layers, such as the first light-emitting zone 51 includes alternately stacked well layers 51a of the first light-emitting zone and alternately stacked barrier layers 51b of the first light-emitting zone, the second light-emitting zone 52 includes alternately stacked well layers 52a of the second light-emitting zone and alternately stacked barrier layers 52b of the second light-emitting zone, and the mth light-emitting zone 53 includes alternately stacked well layers 53a of the mth light-emitting zone and alternately stacked barrier layers 53b of the mth light-emitting zone.

[0029] The well layer 51 a in the first light emitting region has the highest In concentration or the smallest bandgap width.

[0030] The multi-quantum well layer 50 also includes a buffer zone 500, which is arranged between the first light-emitting zone 51 and the adjacent second light-emitting zone 52, or the buffer zone 500 is arranged in the second light-emitting zone 52; it includes at least one of an undoped GaN single layer, a doped GaN single layer and a superlattice structure layer, with a thickness of >10Å.

[0031] When the buffer region 500 is disposed in the second light emitting region 52 , the buffer region 500 may be disposed between two adjacent well layers in the second light emitting region 52 .

[0032] In the multi-quantum well layer 50 of the present invention, the well layer 51a of the first light-emitting zone that grows first has the highest In concentration or the smallest bandgap width, and cooperates with the setting of the buffer zone 500 to balance the differences in the carrier capture capabilities of the well layers of the light-emitting zones due to the different band gaps, alleviate the lattice mismatch caused by the band gap differences of the light-emitting zones, and improve the crystal quality of the light-emitting zones.

[0033] In an embodiment of the present invention, as a preferred embodiment, the thickness of the buffer zone 500 is 100 to 10000Å, including but not limited to 100Å, 150Å, 200Å, 500Å, 1000Å, 2000Å, 3000Å, 5000Å, 6000Å, 8000Å, 9000Å, 10000Å or a range consisting of any two of them.

[0034] In an embodiment of the present invention, as an optional embodiment, the In concentration of the well layer 51a in the first light emitting region is >3×10 20 Atoms / cm 3 ; or the bandgap width of the well layer 51a of the first light-emitting zone is the smallest, that is, not greater than the bandgap width of the well layer of each light-emitting zone in the entire multi-quantum well layer.

[0035] In an embodiment of the present invention, as an optional embodiment, when the buffer region 500 is a doped GaN single layer, the doping element may include at least one of In, Si, Al and Mg.

[0036] Further, the doped GaN monolayer is an InGaN monolayer, the In concentration in the InGaN monolayer is less than or equal to the In concentration in the well layer 52a of the second light-emitting region; the In concentration in the InGaN monolayer is greater than or equal to the In concentration in the well layer of the third light-emitting region adjacent to the second light-emitting region. It should be noted that when m=3, the third light-emitting region is the mth light-emitting region.

[0037] In an embodiment of the present invention, as an optional embodiment, when the doped GaN single layer is an InGaN single layer, the In concentration of the InGaN single layer may be >3×10 20 Atoms / cm 3 .

[0038] In the embodiment of the present invention, as an optional embodiment, the buffer region 500 includes an InGaN single layer and a Si-doped GaN single layer. Further, the buffer region 500 may have the same well layer-barrier layer structure as the third light emitting region.

[0039] In an embodiment of the present invention, as an optional embodiment, when the buffer zone 500 is a superlattice structure layer, the number of periods of the superlattice structure layer is 1 to 50, including but not limited to 1, 2, 5, 8, 10, 20, 30, 40, 50 or a range consisting of any two of them.

[0040] In an embodiment of the present invention, as an optional embodiment, the superlattice structure layer includes at least one of an InGaN / GaN superlattice structure layer, an InGaN / AlGaN superlattice structure layer, an InAlGaN / GaN superlattice structure layer and an InAlGaN / InGaN superlattice structure layer.

[0041] In an embodiment of the present invention, as an optional embodiment, the thickness of a single well layer of the first light-emitting region 51 may be 20 to 60Å.

[0042] In an embodiment of the present invention, as an optional embodiment, the wavelength peaks generated by each light emitting region of the multi-quantum well layer 50 gradually decrease in the first direction. Further, the difference Δλ between the wavelength peaks generated by each adjacent light emitting region is ≤25nm.

[0043] In an embodiment of the present invention, as an optional embodiment, among the wavelength peaks generated by each light-emitting region of the multi-quantum well layer 50, the maximum wavelength peak may be 459-473 nm, and the minimum wavelength peak may be 435-447.5 nm.

[0044] In the embodiment of the present invention, as an optional embodiment, in the multi-quantum well layer 50, the wavelength generated by the first light emitting region 51 can be 459-473 nm.

[0045] In the embodiment of the present invention, as an optional embodiment, the bandgap width of the well layer of each light emitting region of the multi-quantum well layer 50 gradually increases in the first direction.

[0046] In the embodiment of the present invention, as an optional embodiment, the In concentration in the well layer of each light emitting region of the multi-quantum well layer 50 gradually decreases in the first direction.

[0047] In an embodiment of the present invention, as an optional embodiment, the thickness of a single well layer in each light-emitting region of the multi-quantum well layer 50 is substantially consistent in the first direction. Wherein, substantially consistent means that the thickness of a single well layer in each light-emitting region of the multi-quantum well layer 50 is in the first direction, and the thickness of the corresponding single well layer in the adjacent light-emitting region satisfies that the thickness of the subsequent single well layer is in the range of -10% to 10% compared to the thickness of the previous single well layer.

[0048] In an embodiment of the present invention, as an optional embodiment, the periodic structure of the well layer and barrier layer of the first light-emitting zone 51 can be 1 to 5, the periodic structure of the well layer and barrier layer of the second light-emitting zone can be 1 to 5, and the periodic structure of the well layer and barrier layer of the third light-emitting zone can be 1 to 15.

[0049] In the embodiment of the present invention, as an optional embodiment, the multi-quantum well layer 50 further includes an (m+1)th light emitting region 55 close to the P-type semiconductor layer 60 . Figure 3 Another structural schematic diagram of a multi-quantum well layer provided in an embodiment of the present invention. The direction from the N-type semiconductor layer 30 to the P-type semiconductor layer 60 is defined as a first direction, and the multi-quantum well layer includes m+1 groups of light-emitting regions that generate light of different wavelengths along the first direction, including a first light-emitting region 51 closest to the N-type semiconductor layer 30, a second light-emitting region 52 adjacent to the first light-emitting region 51, an m+1th light-emitting region 55 closest to the P-type semiconductor layer 60, an mth light-emitting region 53 next closest to the P-type semiconductor layer 60, and optionally one or more light-emitting regions between the second light-emitting region 52 and the mth light-emitting region 53 (not shown in the figure, represented by ...).

[0050] The m+1th light emitting region 55 includes an m+1th light emitting region well layer 55 a and an m+1th light emitting region barrier layer 55 b which are alternately stacked.

[0051] In an embodiment of the present invention, as an optional embodiment, the (m+1)th light emitting area 55 satisfies at least one of the following conditions: (1) The In concentration of the well layer 55a of the m+1th light-emitting region is greater than the In concentration of the well layer 53a of the mth light-emitting region; (2) The bandgap width of the well layer 55 a of the m+1th light emitting region is smaller than the bandgap width of the well layer 53 a of the mth light emitting region.

[0052] In an embodiment of the present invention, as an optional embodiment, the multi-quantum well layer 50 includes five groups of light-emitting regions, which are respectively a first light-emitting region, a second light-emitting region, a third light-emitting region, a fourth light-emitting region and a fifth light-emitting region along the first direction; and at least one of the following conditions is satisfied: (1) The thickness of a single well layer in the first light-emitting region, the second light-emitting region, the third light-emitting region, the fourth light-emitting region, and the fifth light-emitting region are d 1 d 2 d3 d 4 and d 5 , each thickness satisfies: d 2 ≤d 3 ≤d 4 ≤d 1 , d 4 With d 5 Satisfaction:d 4 >d 5 or 4 <d 5 or 4 =d 5 ; For example, the thickness of a single well layer in each light emitting region includes but is not limited to, d 1 It can be 20~60Å, d 2 It can be 20~60Å, d 3 It can be 20~60Å, d 4 It can be 20~60Å, d 5 It can be 20 to 60 Å; (2) The concentrations of In in the single well layers of the first light-emitting region, the second light-emitting region, the third light-emitting region, the fourth light-emitting region, and the fifth light-emitting region are respectively X 1 , X 2 , X 3 , X 4 and X 5 , each concentration satisfies: X 1 >X 2 >X 3 >X 4 , X 4 With X 5 Satisfaction: X 4 >X 5 or X 4 <X 5 or X 4 =X 5 ; For example, the concentration of In in a single well layer of each light-emitting region includes but is not limited to: 1 Can be 8×10 20 Atoms / cm 3 ~5×10 21 Atoms / cm 3 , X 2 Can be 8×10 20 Atoms / cm 3 ~5×10 21 Atoms / cm 3 , X 3 Can be 8×10 19 Atoms / cm 3 ~8×1020 Atoms / cm 3 , X 4 It can be 5×10 19 Atoms / cm 3 ~7×10 20 Atoms / cm 3 , X 5 It can be 5×10 19 Atoms / cm 3 ~7×10 20 Atoms / cm 3 ; (3) The bandgap widths of the single well layers in the first light-emitting region, the second light-emitting region, the third light-emitting region, the fourth light-emitting region, and the fifth light-emitting region are Eg respectively. 1 , Eg 2 , Eg 3 , Eg 4 and Eg 5 , each bandgap width satisfies: Eg 1 ≤Eg 2 <Eg 3 <Eg 4 , Eg 4 With Eg 5 Satisfaction: Eg 4 >Eg 5 Or Eg 4 <Eg 5 Or Eg 4 =Eg 5 ; (4) The number of periodic structures of well layers and barrier layers in the first light-emitting region, the second light-emitting region, the third light-emitting region, the fourth light-emitting region, and the fifth light-emitting region is Y respectively. 1 , Y 2 , Y 3 , Y 4 and Y 5 , the number of periodic structures satisfies: Y 1 ≤Y 2 ≤Y 3 ≤Y 4 , Y 4 ≥Y 5 ; For example, the number of periodic structures of the well layers and barrier layers in each light-emitting region includes but is not limited to: 1 Can be 1 to 5, Y 2 Can be 1 to 5, Y 3 Can be 1 to 8, Y 4 It can be 1 to 15, Y 5 Can be 1 to 5; (5) The wavelength peaks generated by the first light-emitting area, the second light-emitting area, the third light-emitting area, the fourth light-emitting area and the fifth light-emitting area are λ 1 , 2 , 3 , 4 and λ 5 , each wavelength peak satisfies: λ 1 >λ 2 >λ 3 >λ 4 ,λ 5 >λ 4 ; For example, the wavelength peaks generated by each light-emitting region include but are not limited to, λ 1 It can be 459nm~473nm, λ 2 Can be 459nm~473nm, λ 3 Can be 445nm~457nm, λ 4 Can be 435nm~447nm, λ 5 It can be 437nm~449nm.

[0053] In an embodiment of the present invention, as an optional embodiment, the well layer of the light emitting region includes InGaN, and the barrier layer of the light emitting region includes GaN.

[0054] In an embodiment of the present invention, as an optional embodiment, the thickness of the multi-quantum well layer 50 is 100-300 nm. Further, the thickness of the periodic structure of the well layer and the barrier layer is 10-19 nm, the thickness of a single well layer can be 1-4 nm, and the thickness of a single barrier layer can be 6-15 nm.

[0055] In an embodiment of the present invention, as an optional embodiment, the stress release layer 40 includes an InGaN / GaN superlattice layer. Further, in the stress release layer 40, the concentration of In is less than 3×10 20 Atoms / cm 3 , preferably the concentration of In is greater than 4×10 19 Atoms / cm 3 .

[0056] In an embodiment of the present invention, as an optional embodiment, the stress release layer 40 is doped with Si and / or Al.

[0057] In an embodiment of the present invention, as an optional embodiment, the P-type semiconductor layer 60 includes a P-type AlGaN electron blocking layer and a P-type GaN layer doped with Mg. In the P-type GaN layer doped with Mg, the average doping concentration of Mg is 1×10 19 ~1×10 21 Atoms / cm 3 .

[0058] In an embodiment of the present invention, as an optional embodiment, the N-type semiconductor layer 30 includes an undoped GaN layer and an N-type GaN layer doped with Si. The thickness of the undoped GaN layer may be 1.5 to 2.5 μm, and the thickness of the N-type GaN layer doped with Si may be 1.5 to 2.5 μm; in the N-type GaN layer doped with Si, the doping concentration of Si may be 1×10 19 ~1×10 20 Atoms / cm 3 .

[0059] The light-emitting diode formed by the above-mentioned epitaxial structure can be prepared into a front-mounted structure LED chip, a flip-chip LED structure chip, a vertical structure LED chip, a Mini LED and a Micro LED according to actual application needs, and there is no limitation here. For demonstration, Figure 4 A schematic diagram of a normal LED chip structure is shown, including any of the above-mentioned multi-wavelength light-emitting diode epitaxial structures.

[0060] Furthermore, the light emitting diode further comprises a current blocking layer, a current spreading layer, an N electrode, a P electrode and an insulating layer; The current blocking layer is arranged on the P-type semiconductor layer 60; the current spreading layer is stacked on the P-type semiconductor layer 60 and the current blocking layer; the P electrode is arranged on the current spreading layer and is electrically connected to the P-type semiconductor layer 60; the N electrode is arranged in the N step area and is electrically connected to the N-type semiconductor layer 30; the insulating layer covers the P electrode and the N electrode, and exposes part of the P electrode and the N electrode to form an opening.

[0061] The spectrum distribution of the light-emitting diode is measured under the action of an applied voltage. The spectrum of the multi-quantum well layer has at least three peaks between 420 and 480 nm, including a first peak between 435 and 447 nm, a second peak between 445 and 457 nm, and a third peak between 460 and 473 nm. Among them, the peak intensity of the third peak is the smallest, at least one of the first peak or the second peak has the largest peak intensity, and the ratio of the peak intensity of the third peak to the maximum peak intensity is 0.4 to 0.6; the ratio of the peak intensity of the first peak to the peak intensity of the second peak is 0.8 to 1 or the ratio of the peak intensity of the second peak to the peak intensity of the first peak is 0.8 to 1.

[0062] like Figure 5This is a spectrum distribution diagram of a light-emitting diode chip. The spectrum diagram has three relatively obvious peaks between 435 and 473 nm, among which the peak intensity of the first peak P11 is the largest, and its relative luminous intensity is 1; the peak intensity of the second peak P12 is less than the first peak P11, and its relative luminous intensity is 0.85 to 0.95; the peak intensity of the third peak P13 is less than the second peak P12, and its relative luminous intensity is 0.45 to 0.55.

[0063] Figure 6 This is the spectrum distribution diagram of another light-emitting diode chip. Its spectrum diagram also has three relatively obvious peaks between 435 and 473 nm, but the peak intensity of the second peak P22 is the largest, and its relative luminous intensity is 1; the relative luminous intensity of the first peak P21 is 0.85 to 0.9, and the peak intensity of the third peak P23 is the lowest, and its relative luminous intensity is 0.5 to 0.55.

[0064] Another aspect of the present invention provides a light-emitting module, comprising any one of the above-mentioned light-emitting diodes and a wavelength conversion unit; light generated by the light-emitting diode passes through the wavelength conversion unit and then mixed to generate white light.

[0065] Based on this, embodiments of the present invention provide a multi-wavelength light emitting diode and a light emitting module, which are described below through embodiments.

[0066] Example 1 Figure 7 Schematic diagram of the bandgap structure of the multi-quantum well layer provided in Example 1 of the present invention. The multi-quantum well layer 50 of this embodiment includes 4 groups of light-emitting regions with different bandgap widths, namely, the first light-emitting region, the second light-emitting region, the third light-emitting region and the fourth light-emitting region, so as to generate 4 groups of light with different wavelength peaks λ 1 , 2 , 3 , 4 The bandgap widths of the well layers in the four light-emitting regions are Eg 1 , Eg 2 , Eg 3 and Eg 4 , Eg 1 ≤Eg 2 <Eg 3 <Eg 4 ,λ 1 >λ 2 >λ 3 >λ 4 ; Among them, λ 1 Can be 459~473nm, λ 2 Can be 459~473nm, λ 3 Can be 445nm~457nm, λ 4It can be 435nm~447nm.

[0067] The first light-emitting zone is closest to the N-type semiconductor layer, and includes a periodic structure of first well layers 511 and first barrier layers 512 alternately stacked, and the number of periods can be 1 to 5, such as 1; the second light-emitting zone is adjacent to the first light-emitting zone, and includes a periodic structure of second well layers 521 and second barrier layers 522 alternately stacked, and the number of periods can be 1 to 5, such as 1; the fourth light-emitting zone is closest to the P-type semiconductor layer, and includes a periodic structure of fourth well layers 541 and fourth barrier layers 542 alternately stacked, and the number of periods can be 1 to 15, such as 7; the third light-emitting zone is arranged between the second light-emitting zone and the fourth light-emitting zone, and includes a periodic structure of third well layers 531 and third barrier layers 532 alternately stacked, and the number of periods can be 1 to 8, such as 2.

[0068] Each well layer is an InGaN material layer with different In concentrations, and each barrier layer is a GaN-based material layer. The In concentration in the first well layer 511 is greater than the In concentration in the second well layer 521, the In concentration in the second well layer 521 is greater than the In concentration in the third well layer 531, and the In concentration in the third well layer 531 is greater than the In concentration in the fourth well layer 541. For example, the In concentration in the first well layer 511 can be 8×10 20 Atoms / cm 3 ~5×10 21 Atoms / cm 3 , the In concentration in the second well layer 521 can be 8×10 20 Atoms / cm 3 ~5×10 21 Atoms / cm 3 , the In concentration in the third well layer 531 can be 8×10 19 Atoms / cm 3 ~8×10 20 Atoms / cm 3 , the In concentration in the fourth well layer 541 can be 5×10 19 Atoms / cm 3 ~7×10 20 Atoms / cm 3 .

[0069] The thicknesses of the single well layers in the first light-emitting region, the second light-emitting region, the third light-emitting region and the fourth light-emitting region are d 1 d 2 d 3 d 4 , each thickness satisfies: d 2 ≤d 3 ≤d 4 ≤d 1 For example, the thickness d of the first well layer 511 is1 The thickness d of the second well layer 521, the third well layer 531 and the fourth well layer 541 may be 20 to 60 Å, for example, 40 Å, but not limited thereto. 2 d 3 and d 4 The thickness is substantially the same, which can be 20-60Å, such as 30Å, but not limited thereto. The first barrier layer 512, the second barrier layer 522, the third barrier layer 532, and the fourth barrier layer 542 have substantially the same thickness, ranging from 60-150Å.

[0070] A buffer zone 500 is provided between the first light-emitting zone and the second light-emitting zone. The buffer zone 500 is a GaN-based single layer. The thickness of the buffer zone is d 0 In this embodiment, the buffer region 500 may also be replaced by any one of a doped GaN single layer and a super lattice structure layer.

[0071] In a possible embodiment, the thickness of the buffer zone 500 is 100-10000Å, such as 140Å.

[0072] In a variant implementation, the buffer zone 500 is disposed between two adjacent well layers of the second light emitting region, that is, the buffer zone 500 is disposed between two adjacent second well layers 521 .

[0073] Example 2 Figure 8 Schematic diagram of the bandgap structure of the multi-quantum well layer provided in Example 2 of the present invention. The multi-quantum well layer 50 of this embodiment refers to Example 1, except that: in the multi-quantum well layer 50, a fifth light-emitting region is also included between the fourth light-emitting region and the P-type semiconductor layer.

[0074] The fifth light emitting region is closest to the P-type semiconductor layer, and includes a periodic structure of alternately stacked fifth well layers 551 and fifth barrier layers 552 , and the number of periods may be 1 to 5, such as 1.

[0075] The fifth well layer 551 is an InGaN material layer, and the fifth barrier layer 552 is a GaN-based material layer. The thickness of the fifth well layer 551 is greater than that of the fourth well layer. For example, the thickness d of the fifth well layer 551 is 5 The thickness of the fifth barrier layer 552 is substantially the same as that of the fourth barrier layer 542, and the thickness ranges from 60 to 150 Å.

[0076] The fifth well layer 551 satisfies one or both of the following conditions: (1) The bandgap width of the well layer in the fifth light-emitting region is Eg 5 , the wavelength generated by the fifth light-emitting area is λ 5 ; Eg5<Eg4,λ5 >λ 4 ; Among them, λ 5 Can be 437~449nm; (2) The In concentration in the fifth well layer 551 is greater than the In concentration in the fourth well layer 541. For example, the In concentration in the fifth well layer 551 may be 5×10 19 Atoms / cm 3 ~7×10 20 Atoms / cm 3 .

[0077] Example 3 Fig. 9 Schematic diagram of the bandgap structure of the multi-quantum well layer provided in Example 3 of the present invention. The multi-quantum well layer 50 of this embodiment refers to Example 2, except that the buffer zone 500 arranged between the first light-emitting area and the second light-emitting area is different.

[0078] In this embodiment, the buffer zone 500 between the first light-emitting zone and the second light-emitting zone is an InGaN single layer, and barrier layers are respectively arranged between the buffer zone 500 including the InGaN single layer and the first light-emitting zone and the second light-emitting zone, specifically, a first barrier layer 512 is arranged between the buffer zone 500 and the first well layer, and a second barrier layer 522 is arranged between the buffer zone 500 and the second well layer. The thickness of the InGaN single layer in the buffer zone 500 is 100 to 10000Å, such as 132Å; the In concentration of the buffer zone 500 is greater than or equal to the In concentration of the third well layer 531, and less than or equal to the In concentration of the second well layer 521.

[0079] Example 4 Fig.10 Schematic diagram of the bandgap structure of a multi-quantum well layer provided in Example 4 of the present invention. The multi-quantum well layer 50 of this embodiment refers to Example 2, except that the buffer zone 500 provided between the first light-emitting area and the second light-emitting area is different.

[0080] In this embodiment, the buffer zone 500 between the first light-emitting zone and the second light-emitting zone is a superlattice structure layer. The number of periods of the superlattice structure layer can be 1 to 50, such as 1. The thickness of the buffer zone 500 is 125 to 140Å.

[0081] The superlattice structure layer may be at least one of an InGaN / GaN superlattice structure layer, an InGaN / AlGaN superlattice structure layer, an InAlGaN / GaN superlattice structure layer, and an InAlGaN / InGaN superlattice structure layer.

[0082] Example 5 Fig.11The schematic diagram of the bandgap structure of the multi-quantum well layer provided in Example 5 of the present invention, the multi-quantum well layer 50 of this embodiment includes a first light-emitting region 51 closest to the N-type semiconductor layer, and a second light-emitting region 52, a third light-emitting region, a fourth light-emitting region, and a fifth light-emitting region sequentially arranged on the first light-emitting region 51, and a buffer region 500 arranged between the first light-emitting region 51 and the second light-emitting region 52. The buffer region 500 includes an InGaN layer 501 and a GaN layer 502, wherein the InGaN layer 501 is located between the first barrier layer 512 and the GaN layer 502, wherein the InGaN layer 501 has the same bandgap energy level as the third well layer 531, and the GaN layer 502 is the same as the third barrier layer 532. Specifically, the InGaN layer 501 in the buffer region 500 has the same bandgap energy level as the third well layer 531, and can emit a light beam of the same wavelength.

[0083] The first light-emitting region 51 includes at least one first well layer 511, and the second light-emitting region 52 includes at least one second well layer 521, wherein the band gap energy gaps of the first well layer 511 and the second well layer 521 are the same or similar, and the band gap energy level is the smallest in the entire multi-quantum well layer. Specifically, the In concentration and well layer thickness in the first well layer 511 and the second well layer 521 are the same. The InGaN layer 501 in the buffer zone 500 is the same as at least one third well layer 531 in the third light-emitting zone, the number of the third well layers 531 in the third light-emitting zone is 3 to 5, and the band gap energy level of the third well layer 531 is greater than that of the second well layer 521; the fourth light-emitting zone includes a plurality of fourth well layers 541, the number of the fourth well layers 541 is greater than the number of the third well layers 531, and the band gap energy level Eg4 is greater than the band gap energy level Eg3 of the third well layer 531; the fifth light-emitting zone closest to the P-type semiconductor layer includes at least one fifth well layer 551, whose band gap energy level Eg5 is less than the band gap energy level Eg4 of the fourth well layer 541, wherein the In concentration of the fifth well layer 551 may be the same as the In concentration of the fourth well layer 541, but the thickness of the fifth well layer 551 is greater than the thickness of the fourth well layer 541; or the In concentration in the fifth well layer 551 is greater than the In concentration in the fourth well layer 541, but the thickness of the two well layers may be the same. In addition, at least one barrier layer is disposed between every two adjacent well layers. The barrier layer may be a GaN layer, an AlGaN layer or an InAlGaN layer, and its band gap energy level is higher than that of the well layer.

[0084] Taking Example 2 as an example, the luminous efficiency of the light emitting diode of Example 2 of the present invention at 60 mA is improved by 1% to 2% compared with the luminous efficiency of the traditional light emitting diode.

[0085] From the above, it can be seen that the light-emitting diode of the present invention can better balance the differences in the carrier capture capabilities of each well layer due to the different band gaps of each light-emitting zone by setting a buffer zone between the first light-emitting zone and the second light-emitting zone or setting a buffer zone in the second light-emitting zone, and coordinating the adjustment of the parameters of the remaining light-emitting zones, and can alleviate the lattice mismatch caused by the band gap differences of each light-emitting zone, improve the crystal quality of the light-emitting zone, and achieve the effect of improving the luminescence efficiency.

[0086] An embodiment of the present invention further provides a method for preparing a multi-wavelength light emitting diode, comprising the following steps: The first half of the buffer layer 20 is grown on the substrate 10 for 1 minute, in order to compensate for the lattice mismatch and form nucleation islands, and the temperature of this layer is controlled at 800°C and the pressure is 150 torr. The second half of the buffer layer 20 is then grown for 10 to 25 minutes, and the temperature is controlled at 1120°C and the pressure is 200 torr, in order to grow GaN with high crystal growth quality and low defect density.

[0087] The N-type semiconductor layer 30 is grown on the buffer layer 20 to provide electrons. The N-type semiconductor layer 30 is doped with Si to provide electrons. The temperature is controlled at 1050°C and the pressure is 200 torr. The concentration of silicon doping is 1×10 19 ~2×10 20 Atoms / cm 3 .

[0088] A stress release layer 40 is grown on the N-type semiconductor layer 30 to release the compressive stress caused by the lattice mismatch between the subsequently grown InGaN quantum well and the GaN of the N-type semiconductor layer 30. The temperature is controlled at 800-900°C and the pressure is 200 torr. The layer can be a single layer or a multilayer structure, and can be doped with elements such as Si / Al / In. The concentration of silicon doping is 1×10 17 Atoms / cm 3 ~5×10 18 Atoms / cm 3 , the indium doping concentration is 0~1×10 20 Atoms / cm 3 .

[0089] The multi-quantum well layer 50 is continuously grown on the stress release layer 40. The multi-quantum well layer 50 emits light through the convergence of electrons and holes. The temperature of the layer is controlled at 700-800°C and the pressure is 200tor.

[0090] A P-type semiconductor layer 60 is grown on the multi-quantum well layer 50. The function of this layer is to provide holes for the device. The temperature of this layer is controlled at 700-1000°C and the pressure is 1000tor.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-wavelength light emitting diode, characterized in that: include: A multi-quantum well layer disposed between the N-type semiconductor layer and the P-type semiconductor layer; A direction from the N-type semiconductor layer to the P-type semiconductor layer is defined as a first direction, the multi-quantum well layer includes m groups of light-emitting regions that generate light of different wavelengths along the first direction, each light-emitting region includes at least one well layer and one barrier layer, wherein m≥3; The first well layer in the first light-emitting region closest to the N-type semiconductor layer in the multi-quantum well layer has the highest In concentration or the smallest bandgap width; the second light-emitting region including the second well layer and the second barrier layer is arranged on the first light-emitting region, wherein the bandgap width of the second well layer is greater than or equal to the first well layer; the third light-emitting region including the third well layer and the third barrier layer is arranged on the second light-emitting region, wherein the bandgap width of the third well layer is greater than that of the second well layer; The multi-quantum well layer also includes a buffer zone; the buffer zone is arranged between the first light-emitting zone and the second light-emitting zone, or the buffer zone is arranged in the second light-emitting zone; the bandgap width of the buffer zone is greater than that of the second well layer.

2. The multi-wavelength light emitting diode according to claim 1, characterized in that: The buffer zone includes at least one of a non-doped GaN single layer, a doped GaN single layer and a super lattice structure layer, and the doping element is at least one of In, Si, Al and Mg.

3. The multi-wavelength light emitting diode according to claim 2, characterized in that: The buffer zone includes an InGaN single layer and a GaN single layer, wherein the In concentration in the InGaN single layer is less than or equal to the In concentration in the second well layer; and the In concentration in the InGaN single layer is greater than or equal to the In concentration in the third well layer.

4. The multi-wavelength light emitting diode according to claim 2, characterized in that: The superlattice structure layer has a period number of 1 to 50; The superlattice structure layer includes at least one of an InGaN / GaN superlattice structure layer, an InGaN / AlGaN superlattice structure layer, an InAlGaN / GaN superlattice structure layer, and an InAlGaN / InGaN superlattice structure layer.

5. The multi-wavelength light emitting diode according to claim 1, characterized in that: The multi-quantum well layer satisfies at least one of the following conditions: (1) The peak wavelengths generated by each light-emitting region of the multi-quantum well layer gradually decrease in the first direction; the difference Δλ between the peak wavelengths generated by adjacent light-emitting regions is ≤25 nm; (2) the bandgap width of the well layer in the first light-emitting region to the bandgap width of the well layer in the mth light-emitting region gradually increases in the first direction; (3) the In concentration in the well layer of the first light-emitting region to the In concentration in the well layer of the mth light-emitting region gradually decreases in the first direction; (4) The spectrum of the multi-quantum well layer has at least three peaks between 420 and 480 nm, including a first peak between 435 and 447 nm, a second peak between 445 and 457 nm, and a third peak between 460 and 473 nm; Among them, the peak intensity of the third peak is the smallest, at least one of the first peak or the second peak has the maximum peak intensity, and the ratio of the peak intensity of the third peak to the maximum peak intensity is 0.4 to 0.6; the ratio of the peak intensity of the first peak to the peak intensity of the second peak is 0.8 to 1 or the ratio of the peak intensity of the second peak to the peak intensity of the first peak is 0.8 to 1.

6. The multi-wavelength light emitting diode according to claim 3, characterized in that: A well layer and a barrier layer in each light-emitting region are defined as a period. The number of periods in the first light-emitting region is 1 to 5, the number of periods in the second light-emitting region is 1 to 5, and the number of periods in the third light-emitting region is 1 to 15.

7. The multi-wavelength light emitting diode according to any one of claims 1 to 6, characterized in that: The multi-quantum well layer also includes an m+1th light-emitting region close to the P-type semiconductor layer, and a light-emitting region adjacent to the m+1th light-emitting region and away from the P-type semiconductor layer is the mth light-emitting region, and the m+1th light-emitting region satisfies at least one of the following conditions: (1) The In concentration of the well layer of the m+1th light-emitting region is greater than the In concentration of the well layer of the mth light-emitting region; (2) The bandgap width of the well layer of the m+1th light-emitting region is smaller than the bandgap width of the well layer of the mth light-emitting region.

8. The multi-wavelength light emitting diode according to claim 1, characterized in that: The multi-quantum well layer includes five groups of light-emitting regions, which are respectively a first light-emitting region, a second light-emitting region, a third light-emitting region, a fourth light-emitting region and a fifth light-emitting region along the first direction.

9. The multi-wavelength light emitting diode according to claim 8, characterized in that: The thicknesses of the single well layers of the first light-emitting zone, the second light-emitting zone, the third light-emitting zone, the fourth light-emitting zone and the fifth light-emitting zone are d1, d2, d3, d4 and d5 respectively, and each thickness satisfies: d2≤d3≤d4≤d1, and d4 and d5 satisfy: d4>d5 or d4<d5 or d4=d5.

10. The multi-wavelength light emitting diode according to claim 8, characterized in that: The concentrations of In in the single well layers of the first light-emitting zone, the second light-emitting zone, the third light-emitting zone, the fourth light-emitting zone and the fifth light-emitting zone are X1, X2, X3, X4 and X5 respectively, and each concentration satisfies: X1>X2>X3>X4, and X4 and X5 satisfy: X4>X5 or X4<X5 or X4=X5.

11. The multi-wavelength light emitting diode according to claim 8, characterized in that: The bandgap widths of the single well layers of the first light-emitting zone, the second light-emitting zone, the third light-emitting zone, the fourth light-emitting zone and the fifth light-emitting zone are Eg1, Eg2, Eg3, Eg4 and Eg5 respectively, and each bandgap width satisfies: Eg1≤Eg2<Eg3<Eg4, and Eg4 and Eg5 satisfy: Eg4>Eg5 or Eg4<Eg5 or Eg4=Eg5.

12. The multi-wavelength light emitting diode according to claim 8, characterized in that: The number of periodic structures of the well layers and barrier layers of the first light-emitting zone, the second light-emitting zone, the third light-emitting zone, the fourth light-emitting zone and the fifth light-emitting zone are Y1, Y2, Y3, Y4 and Y5 respectively, and the number of each periodic structure satisfies: Y1≤Y2≤Y3≤Y4, Y4≥Y5.

13. The multi-wavelength light emitting diode according to claim 8, characterized in that: The wavelength peaks generated by the first light-emitting area, the second light-emitting area, the third light-emitting area, the fourth light-emitting area and the fifth light-emitting area are λ1, λ2, λ3, λ4 and λ5 respectively, and each wavelength peak satisfies: λ1>λ2>λ3>λ4, λ5>λ4.

14. A light emitting module, characterized in that: It comprises the multi-wavelength light emitting diode according to any one of claims 1 to 13, wherein the light generated by the light emitting diode passes through a wavelength conversion unit and then is mixed to generate white light.

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