CN114361308A - Deep ultraviolet light-emitting device with double electron blocking layers and preparation method thereof - Google Patents
Deep ultraviolet light-emitting device with double electron blocking layers and preparation method thereof Download PDFInfo
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Abstract
The invention discloses a deep ultraviolet light-emitting device with double electron barrier layers and a preparation method thereof, belonging to the technical field of light-emitting diode preparation.
Description
Technical Field
The invention relates to the technical field of light emitting diode preparation, in particular to a deep ultraviolet light emitting device with double electron blocking layers and a preparation method thereof.
Background
A light-emitting diode (LED) is a commonly used light-emitting device, and has been developed for over thirty years since the present invention. Compared with the traditional light source, the LED can emit light instantly when being started, does not need preheating time, has longer service life and does not pollute the environment. Therefore, with the continuous progress of technology and development of technology, LEDs have been successful in the visible light range, and can replace the conventional tungsten filament lamp and fluorescent tube for daily illumination and display. However, there is still a great room for improvement in the performance of the ultraviolet LEDs, especially deep ultraviolet LEDs.
The deep ultraviolet band can be divided into the following three regions according to the wavelength, and the deep ultraviolet band is firstly called UVA or long-wave ultraviolet from 400nm to 320 nm; secondly, from 320nm to 280nm, the ultraviolet light is called UVB or ultraviolet region; finally, from 280nm to 100nm is called UVC or short wave ultraviolet. Ultraviolet light is widely applied to various fields such as disinfection, food, medicine, medical treatment and the like, and a deep ultraviolet region comprises two regions of UVB and UVC, and has irreplaceable effects in sterilization and disinfection and short-wave ultraviolet communication. And the deep ultraviolet LED realizes light emission in an ultraviolet band by adding aluminum nitride (AlN) to a gallium nitride (GaN) material, and realizes a change in wavelength by changing the composition of aluminum therein. And when the aluminum component increases, the hole ionization quantity in the ultraviolet LED is greatly reduced, so that the electron overflow phenomenon occurs, even if the electron blocking layer is added to block electrons, electrons still cross the electron blocking layer to be compounded with the holes to the P-type layer, the quantum efficiency of the device is greatly reduced, and the device has a certain difference with the traditional ultraviolet mercury lamp.
In order to prevent surplus electrons from overflowing to the P-type layer to be compounded, an electron blocking layer with high Al component is added between the P-type layer and the quantum well in the industry to solve the problem. This structure, although blocking electrons to some extent, does not effectively solve the problem of electron overflow and also brings about many new problems, for example, the electron blocking layer not only blocks electron overflow but also blocks injection of holes into the quantum well; the change of the electron blocking layer with high Al component and the blocking and accumulation of electrons in front of the electron blocking layer can cause the bending of an energy band, so that the light emitting of an LED device generates a parasitic peak, and the quality of the device is influenced.
Disclosure of Invention
In order to solve the technical problems, the invention provides a deep ultraviolet light emitting device with a double electron barrier layer and a preparation method thereof, which can effectively solve the electron overflow effect, increase the number of holes injected into a multi-quantum well layer, weaken the energy band bending phenomenon and improve the light emitting quality of the device.
In order to achieve the purpose, the technical scheme adopted by the invention for solving the technical problems is as follows: the deep ultraviolet light-emitting device with the double electron barrier layers comprises an electron injection layer, a multi-quantum well layer and a hole injection layer which are arranged from bottom to top, wherein a first electron barrier layer with an aluminum component gradually changed in a gradient manner is arranged between the electron injection layer and the multi-quantum well layer, and a second electron barrier layer with an aluminum component gradually changed in a peak manner is arranged between the hole injection layer and the multi-quantum well layer.
One side of the first electron blocking layer, which is in contact with the electron injection layer, is high Al component AlaGa1-aN, a is more than or equal to 0.4 and less than or equal to 0.9, and the side of the first electron barrier layer, which is in contact with the multi-quantum well layer, is low-Al component AlbGa1-bB is more than or equal to 0.3 and less than or equal to 0.9, the content of the Al component in the middle part is linearly reduced and changed, and the linear reduction gradient is a constant k1，k1In the range of 0<k1≤0.3。
The thickness of the first electron barrier layer is 2-100 nm, the maximum value of the Al component content of the first electron barrier layer is larger than the Al component content of the electron injection layer, and the minimum value of the Al component content of the first electron barrier layer is equal to the Al component content of the multi-quantum well layer on the side close to the first electron barrier layer.
The second electron blocking layer comprises an Al component increasing layer and an Al component decreasing layer which are sequentially arranged along the epitaxial growth direction, and the Al component increasing layer is connected with the Al component decreasing layerThe Al component content of the junction of the Al component decreasing layer is equal, and the high Al component Al is arranged at the junction of the Al component increasing layer and the Al component decreasing layercGa1-cN，0.6≤c≤1。
One side of the Al component increasing layer, which is in contact with the multi-quantum well layer, is low-Al component AldGa1-dD is more than or equal to 0.3 and less than or equal to 0.9, the content of the Al component in the middle part of the Al component increasing layer is changed in a linear increasing way, and the linear increasing gradient is a constant k2，k2In the range of 0<k2≤0.35。
One side of the Al component decreasing layer, which is in contact with the hole injection layer, is low-Al component AleGa1-eN is more than or equal to 0.3 and less than or equal to 0.9, the content of the Al component in the middle part of the Al component increasing layer is linearly decreased and changed, and the linearly increasing gradient is a constant k3，k3In the range of 0<k3≤0.35。
The thickness of the second electron blocking layer is set to be 5-50 nm, the thickness of the Al component increasing layer is set to be 2-30 nm, and the thickness of the Al component decreasing layer is set to be 2-30 nm; the Al component content of the side, close to the multi-quantum well layer, of the second electron barrier layer is equal to the Al component content of the side, close to the second electron barrier layer, of the multi-quantum well layer, and the Al component content of the side, close to the hole injection layer, of the second electron barrier layer is equal to the Al component content of the hole injection layer.
The electron injection layer is arranged to be an n-AlGaN layer, and the composition material of the n-AlGaN layer is Si-doped AlxGa1-xX is more than or equal to 0.5 and less than or equal to 0.7, the thickness of the electron injection layer is set to be 500-3000 nm, and the doping concentration of Si is 1 x 1018～1*1020cm-3Electron concentration after doping is 1 x 1018～1*1020cm-3(ii) a The composition material of the multi-quantum well layer is AlyGa1-yY is more than or equal to 0.3 and less than or equal to 0.6, the multi-quantum well layer comprises AlGaN potential well layers with the thickness of 1-5 nm and AlGaN barrier layers with the thickness of 4-15 nm which are alternately grown, and the repetition period is 3-10; the hole injection layer is arranged as a p-AlGaN layer, and the p-AlGaN layer is made of Mg-doped AlzGa1-zZ is more than or equal to 0.5 and less than or equal to 0.7, the thickness of the hole injection layer is set to be 20-100 nm, and the concentration of Mg doping is 1 x 1018～1*1020cm-3。
The light-emitting diode also comprises a substrate layer, a buffer layer I, an AlN intrinsic layer and a buffer layer II which are sequentially arranged from bottom to top, wherein the electron injection layer grows on the buffer layer II, and an N-type electrode is arranged on the electron injection layer; the hole injection layer is provided with a P-GaN layer, the P-GaN layer is provided with a P-type electrode, and the N-type electrode is connected with the P-type electrode in an ohmic contact mode.
A method for preparing a deep ultraviolet light-emitting device with a double electron blocking layer comprises the following steps:
step 1: sequentially growing a buffer layer I, an AlN intrinsic layer, a buffer layer II and an electron injection layer on a substrate;
step 2: linearly reducing the flow of the metal organic source TMAl along with the growth line, and growing a first electron blocking layer;
and step 3: growing a multi-quantum well layer on the first electron barrier layer;
and 4, step 4: the flow of TMAl which is a metal organic source is increased linearly along with the growth line and then is reduced, and a second electron blocking layer is grown;
and 5: sequentially growing a hole injection layer and a p-GaN layer on the second electron blocking layer;
step 6: and manufacturing an ohmic contact electrode on the electron injection layer and the p-GaN layer.
The invention has the beneficial effects that:
1. according to the invention, the first electron barrier layer is arranged between the electron injection layer and the multi-quantum well layer, and the aluminum component in the first electron barrier layer is linearly decreased progressively along the epitaxial growth direction, so that the content of the Al component on one side of the first electron barrier layer close to the electron injection layer is greater than that of the electron injection layer, thereby limiting a large amount of electrons from flowing into the multi-quantum well layer and effectively solving the electron overflow effect; the gradual change of the Al component can generate an electric field opposite to the polarization of the multi-quantum well layer, offset part of the polarization electric field and reduce the quantum Stark effect of the multi-quantum well layer, so that the recombination efficiency of hole electron pairs is increased and the luminous efficiency of the device is improved; two-dimensional electron gas is generated before the first electron blocking layer due to the blocking of electrons by the barrier height, the uniformity of the electrons in the space distribution can be improved, and the effect of current spreading is achieved.
2. According to the invention, the second electron barrier layer is arranged between the multi-quantum well layer and the hole injection layer, and the second electron barrier layer adopts a mode that Al components are doped in a spike-type gradual change manner, so that three-dimensional hole gas can be formed on one side close to the hole injection layer through the induction of the linearly-decreased Al component content, and the injection of holes is improved; meanwhile, the energy band bending can be weakened by the linearly increasing Al component content on one side close to the multi-quantum well layer, and the light emitting quality of the device is improved.
3. According to the invention, the double electron barrier layers are arranged above and below the multi-quantum well layer and are based on AlGaN with the Al component content gradient gradually changed linearly, so that the lattice mismatch and the piezoelectric polarization effect caused by the change of the layer structure are reduced, and the production quality of the device is improved.
In conclusion, the invention effectively solves the electron overflow effect by improving the device structure and the electron barrier layer structure, increases the number of holes injected into the multi-quantum well layer, weakens the energy band bending phenomenon and improves the light emitting quality of the device.
Drawings
The contents of the expressions in the various figures of the present specification and the labels in the figures are briefly described as follows:
fig. 1 is a schematic structural view of a deep ultraviolet light emitting device in the present invention;
FIG. 2 is a graph comparing simulation results of conduction band structures of example one (left diagram) of the present invention and comparative example one (right diagram);
FIG. 3 is a comparison graph of valence band structure simulation results of example one (left) of the present invention and comparative example one (right);
the labels in the above figures are: 1. the electron injection layer, the multiple quantum well layer, the hole injection layer, the first electron barrier layer, the second electron barrier layer, the Al component increasing layer, the Al component decreasing layer, the substrate layer, the buffer layer I, the AlN intrinsic layer, the buffer layer II, the N-type electrode, the P-GaN layer and the P-type electrode are sequentially arranged from top to bottom, and the electron injection layer, the hole injection layer, the first electron barrier layer, the second electron barrier layer, the Al component increasing layer, the Al component decreasing layer, the substrate layer, the buffer layer I, the AlN intrinsic layer, the buffer layer II, the N-type electrode, the P-GaN layer and the P-type electrode are sequentially arranged from top to bottom.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and the following embodiments are used for illustrating the present invention and are not intended to limit the scope of the present invention.
In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
The specific implementation scheme of the invention is as follows: as shown in figure 1, the deep ultraviolet light-emitting device with the double electron blocking layers comprises a substrate layer, a buffer layer I, an AlN intrinsic layer, a buffer layer II, an electron injection layer, a multi-quantum well layer and a hole injection layer which are arranged from bottom to top, wherein an N-type electrode is arranged on the electron injection layer, a P-GaN layer is arranged on the hole injection layer, a P-type electrode is arranged on the P-GaN layer, and the N-type electrode is connected with the P-type electrode in an ohmic contact mode.
The substrate layer can be a sapphire substrate, the buffer layer I is formed by depositing undoped AlN with uniform components on the substrate by a chemical vapor deposition method, and the thickness of the buffer layer I is 10-50 nm; wherein the AlN intrinsic layer isDepositing undoped AlN with uniform components on the buffer layer I by using a chemical vapor deposition method, wherein the thickness is 100-3000 nm; wherein the buffer layer II adopts a chemical vapor deposition method to deposit undoped Al with uniform components on the AlN intrinsic layerfGa1-fN, the thickness is 50-300nm, wherein f is more than or equal to 0.5 and less than or equal to 0.8; the electron injection layer is arranged as an n-AlGaN layer, and the composition material of the n-AlGaN layer is Si-doped AlxGa1-xX is more than or equal to 0.5 and less than or equal to 0.7, the thickness of the electron injection layer is set to be 500-3000 nm, and the doping concentration of Si is 1 x 1018～1*1020cm-3Electron concentration after doping is 1 x 1018～1*1020cm-3(ii) a Wherein the composition material of the multiple quantum well layer is AlyGa1-yY is more than or equal to 0.3 and less than or equal to 0.6, the multi-quantum well layer comprises AlGaN barrier layers with the thickness of 4-15 nm and AlGaN potential well layers with the thickness of 1-5 nm which are alternately grown, and the repetition period is 3-10; wherein the hole injection layer is arranged as a p-AlGaN layer, and the p-AlGaN layer is made of Mg-doped AlzGa1-zZ is more than or equal to 0.5 and less than or equal to 0.7, the thickness is set to be 20-100 nm, and the concentration of Mg doping is 1 x 1018～1*1020cm-3。
Specifically, a first electron barrier layer with an aluminum component in gradient is arranged between the electron injection layer and the multiple quantum well layer, a second electron barrier layer with an aluminum component in peak gradient is arranged between the hole injection layer and the multiple quantum well layer, the double electron barrier layers are arranged based on the linear gradient of the content gradient of the aluminum component, lattice mismatch and piezoelectric polarization effect caused by layer structure change are reduced, production quality of the device is improved, the first electron barrier layer can limit a large amount of electrons from flowing into the multiple quantum well layer, an electron overflow effect is effectively solved, luminous efficiency of the device is improved, the injection amount of holes can be improved by the second electron barrier layer, energy band bending is weakened, luminous efficiency of the device is improved, and quality of the device is improved.
Specifically, the thickness of the first electron blocking layer is 2-100 nm, and one side of the first electron blocking layer, which is in contact with the electron injection layer, is high-Al component AlaGa1-aN, 0.4-0.9, the first electron blocking layer and multiple quantumOne side contacted with the sub-well layer is low Al component AlbGa1-bB is more than or equal to 0.3 and less than or equal to 0.9, the content of the Al component in the middle part is linearly reduced and changed, and the linear reduction gradient is a constant k1Wherein k is1＝(a-b)/t1，t1Is the thickness of the first electron blocking layer, k1Has a maximum value of 0.3, k1Tends to 0, and therefore k1In the range of 0<k1Less than or equal to 0.3. The Al component content in the first electronic barrier layer decreases progressively along the growth direction, the maximum value of the Al component content of the first electronic barrier layer is larger than the Al component content of the electron injection layer, and the minimum value of the Al component content of the first electronic barrier layer is equal to the Al component content of the side (AlGaN potential well layer) of the multi-quantum well layer close to the first electronic barrier layer. Because the Al component content of the first electron barrier layer close to one side of the electron injection layer is greater than that of the electron injection layer, a large amount of electrons can be limited from flowing into the multi-quantum well layer, and the electron overflow effect is effectively solved; the gradual change of the Al component can generate an electric field opposite to the polarization of the multi-quantum well layer, offset part of the polarization electric field and reduce the quantum Stark effect of the multi-quantum well layer, so that the recombination efficiency of hole electron pairs is increased and the luminous efficiency of the device is improved; two-dimensional electron gas is generated before the first electron blocking layer due to the blocking of electrons by the barrier height, the uniformity of the electrons in the space distribution can be improved, and the effect of current spreading is achieved.
Specifically, the thickness of the second electron blocking layer is set to be 5-50 nm, the second electron blocking layer comprises an Al component increasing layer and an Al component decreasing layer, the Al component increasing layer and the Al component decreasing layer are sequentially arranged along the epitaxial growth direction and have the thicknesses of 2-30 nm, the Al component content of the junction of the Al component increasing layer and the Al component decreasing layer is equal, and the junction of the Al component increasing layer and the Al component decreasing layer is high-Al component AlcGa1-cN，0.6≤c≤1。
Wherein the side of the Al component increasing layer contacting with the multi-quantum well layer is low Al component AldGa1-dD is more than or equal to 0.3 and less than or equal to 0.9, the content of the Al component in the middle part of the Al component increasing layer is changed in a linear increasing way, and the linear increasing gradient is a constant k2Wherein k is2＝(c-d)/t2，t2Thickness of the Al component increasing layer, k2Has a maximum value of 0.35, k2Is close to 0, and therefore k2In the range of 0<k2Less than or equal to 0.35. The Al component content of the side of the Al component increasing layer close to the multi-quantum well layer is equal to the Al component content of the side (AlGaN barrier layer) of the multi-quantum well layer close to the Al component increasing layer.
The side of the Al component decreasing layer contacting with the hole injection layer is low Al component AleGa1-eN is more than or equal to 0.3 and less than or equal to 0.9, the content of the Al component in the middle part of the Al component increasing layer is linearly decreased and changed, and the linearly increasing gradient is a constant k3Wherein k is3＝(c-e)/t3，t3Thickness of the Al component increasing layer, k3Has a maximum value of 0.35, k3Is close to 0, and therefore k3In the range of 0<k3Less than or equal to 0.35. The Al component content of the Al component decreasing layer on the side close to the hole injecting layer is equal to the Al component content of the hole injecting layer.
Different from the traditional electron blocking layer with uniform composition, the AlGaN second electron blocking layer with specially changed Al composition is adopted, so that the Al content in the second electron blocking layer presents a peak-type change of firstly rising and then falling. The second electron blocking layer with the Al component changing in a rising and descending manner avoids the mutation of the Al component between layers due to the gradual change of the Al component, so that the piezoelectric polarization effect and the polarization electric field generated by the mutation of the Al component are relieved; the problem of energy band bending caused by the polarization effect generated by the fact that the barrier layer is close to the second electron barrier layer in the multi-quantum well layer is solved; meanwhile, the content of the Al component is reduced from the maximum value to be the same as that of the Al component of the hole injection layer, and three-position hole gas can be formed by the induction of a polarization electric field generated by the gradual change of the Al component, so that the quantity of holes injected into the multi-quantum well layer is effectively increased, and the luminous efficiency of the device is further improved.
The preparation method of the deep ultraviolet light-emitting device comprises the following steps:
step 1: sequentially growing a buffer layer I, an AlN intrinsic layer, a buffer layer II and an electron injection layer on a substrate: 1) heating the substrate layer to 500-1000 ℃ in an MOCVD reaction chamber, introducing metal organic source TMAl for 1-10 min in advance, growing a buffer layer I with the thickness of 10-50 nm on the substrate, then heating to 1000-1400 ℃, growing an intrinsic layer with the thickness of 100-3000 nmAl on the buffer layer I, wherein the buffer layer I and the intrinsic layer are formed by depositing undoped AlN with uniform components, and the total thickness of the buffer layer I and the intrinsic layer is 500-3000 nm;
2) adjusting the temperature to 900-1300 ℃, and selecting Al with uniform componentsgGa1-gG is more than or equal to 0.5 and less than or equal to 0.8, a non-doped AlGaN layer with the thickness of 50-300nm is deposited and grown to form a buffer layer II, a Si-doped N-AlGaN layer with the thickness of 500-3000 nm is grown on the buffer layer II to form an electron injection layer, and the doping concentration of Si is 1 x 1018～1*1021cm-3Electron concentration after doping is 1 x 1018～1*1020cm-3；
Step 2: and (3) linearly reducing the flow of TMAl (metal organic source) along with the growth line, and growing the first electron blocking layer: adjusting the temperature to 800-1300 ℃, changing the flow of introducing a metal organic source TMAl, wherein the TMAl flow is linearly reduced along with the growth of the wire, and the first electron barrier layer with the thickness of 2-100 nm is grown;
and step 3: growing a multi-quantum well layer on the first electron barrier layer: adjusting the temperature to 900-1200 ℃, changing the flow of introducing a metal organic source TMAl, and alternately growing an AlGaN potential well layer with the thickness of 1-5 nm and an AlGaN barrier layer with the thickness of 4-15 nm with the repetition period of 3-10;
and 4, step 4: and (3) reducing the flow of the TMAl which is introduced into the metal organic source after linear growth along with the growth line, and growing a second electron blocking layer: adjusting the temperature to 900-1400 ℃, changing the flow of TMAl introduced into the metal organic source, wherein the TMAl flow is increased linearly along with the growth of the Al component gradient layer with the thickness of 2-30 nm, the TMAl flow is decreased linearly along with the growth of the Al component gradient layer with the thickness of 2-30 nm;
and 5: and sequentially growing a hole injection layer and a p-GaN layer on the second electron blocking layer: adjusting the temperature to 700-1200 ℃, and growing a Mg-doped p-AlGaN layer with the thickness of 20-100 nm on the Al component decreasing layer, wherein the Mg doping concentration is 1 x 1018～1*1020cm-3Forming a hole injection layer; adjusting the temperature to 700-1100 ℃, and growing a Mg-doped p-GaN layer with the thickness of 20-100 nm on the p-AlGaN layer, wherein the Mg doping concentration is 1 x 1018～1*1020cm-3；
Step 6: and respectively manufacturing an N-type electrode and a P-type electrode on the N-AlGaN layer and the P-GaN layer, and enabling the N-type electrode and the P-type electrode to be in ohmic contact.
Example one
The preparation method of the deep ultraviolet light-emitting device comprises the following specific steps:
1) under the condition of 960 ℃, introducing a metal organic source TMAl for 1min in advance, and then growing an AlN buffer layer I with the thickness of 20nm on the sapphire substrate; raising the temperature to 1300 ℃, and growing an AlN intrinsic layer with the thickness of 1480nm on the buffer layer I.
2) Cooling to 1150 deg.C, growing a non-doped AlGaN layer with a thickness of 300nm on the AlN intrinsic layer, and growing a 1500nm thick n-AlGaN electron injection layer on the non-doped AlGaN layer, wherein the n-AlGaN electron injection layer is Si-doped Al0.65Ga0.35The doping concentration of N and Si is 1 x 1019cm-3Electron concentration after doping is 5 x 1018cm-3。
3) Growing a first electron blocking layer on the electron injection layer at 1100 deg.C, wherein the initial deposition material is Al0.7Ga0.3N, changing the content of the Al component by reducing the introduction amount of TMAl serving as a metal organic source to gradually change the content of the Al component to Al0.55Ga0.45N, the specific thickness is 20 nm.
4) Cooling to 960 deg.C, growing multiple quantum well layer on the first electron barrier layer, wherein the multiple quantum well layer comprises AlGaN potential well layer and AlGaN barrier layer, and specifically, the AlGaN potential well layer is made of Al0.45Ga0.55The N, AlGaN barrier layer is made of Al0.55Ga0.45N, repeat for 5 cycles, and finally terminate with an AlGaN barrier layer.
5) And growing a second electron barrier layer on the multi-quantum well layer at 1200 ℃. The starting deposition material is Al0.55Ga0.45N, by changing the metal organic sourceThe introduction amount of TMAl is changed to change the content of Al component, so that the content of Al component is increased to Al first0.8Ga0.2N is reduced to Al0.65Ga0.35And N is added. Specifically, the thickness of the Al component increasing layer was 7nm, and the thickness of the Al component decreasing layer was 20 nm.
6) Growing a p-AlGaN hole injection layer on the second electron blocking layer at 1100 ℃, wherein the p-AlGaN hole injection layer is Mg-doped Al0.65Ga0.35N with a thickness of 60nm and a Mg doping concentration of 1 x 1020～5*1020cm-3(ii) a And growing a p-GaN layer on the p-AlGaN hole injection layer at 1000 ℃ and with the thickness of 50 nm.
7) And respectively manufacturing an N-type electrode and a P-type electrode on the N-AlGaN layer and the P-GaN layer, and enabling the N-type electrode and the P-type electrode to be in ohmic contact.
Comparative example 1
The difference from the first embodiment is that the structure of the deep ultraviolet light emitting device in the first embodiment does not include the first electron blocking layer in the first embodiment, and the second electron blocking layer is Al having a uniform composition0.8Ga0.2N。
The preparation method is different from the first embodiment in that:
3) keeping the temperature at 1100 ℃, keeping the growth of the n-AlGaN electron injection layer, and growing 20nm again on the original basis.
4) And alternately growing AlGaN potential well layers and AlGaN barrier layers on the electron injection layer at 960 ℃, and repeatedly growing an AlGaN barrier layer with the thickness of 7nm after 5 cycles to ensure that the multi-quantum well layer is finished by the AlGaN barrier layers.
5) Growing an electron barrier layer on the multi-quantum well layer at 1200 ℃, wherein the specific composition material is Al0.8Ga0.2N, thickness 20 nm.
After the light emitting devices of the first embodiment and the first comparative example were loaded with a voltage of 15V, simulation was performed by Slivaco software to obtain a comparison graph of the conduction band structure simulation results shown in fig. 2 and a comparison graph of the valence band structure simulation results shown in fig. 3.
Fig. 2 is a graph comparing a conduction band structure at a voltage of 15V in example one with that in comparative example one, wherein the horizontal axis represents a thickness of the light emitting diode and the vertical axis represents electron energy. The left figure shows a dual graded electron blocking layer structure of an example, and the right figure shows a uniform single electron blocking layer structure of a comparative example. By comparison, in the first embodiment, the electron energy is increased in front of the first electron blocking layer (the gray area on the right side), an effective electron barrier is formed, and the effect of blocking electron overflow can be achieved; the band bending of the second electron blocking layer (the gray region on the left) before the multiple quantum well layer is effectively improved.
As shown in fig. 3, the comparison between the valence band structure of the first example and the first comparative example at a voltage of 15V is shown, wherein the horizontal axis represents the thickness of the light emitting diode and the vertical axis represents the hole energy. The left figure is the structure of the dual-gradient electron blocking layer of the embodiment, and the right figure is the structure of the uniform single electron blocking layer of the comparative example. Due to the introduction of the double-gradient electron blocking layer, the carrier injection efficiency and the luminous efficiency of the device are effectively improved, and the luminous efficiency is improved by nearly 30% under the condition of 100mA current.
In conclusion, the invention effectively solves the electron overflow effect by improving the device structure and the electron barrier layer structure, increases the number of holes injected into the multi-quantum well layer, weakens the energy band bending phenomenon and improves the light emitting quality of the device.
While the foregoing is directed to the principles of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
Claims (10)
1. The deep ultraviolet light-emitting device with the double electron barrier layers is characterized by comprising an electron injection layer, a multi-quantum well layer and a hole injection layer which are arranged from bottom to top, wherein a first electron barrier layer with aluminum components gradually changed in a gradient manner is arranged between the electron injection layer and the multi-quantum well layer, and a second electron barrier layer with aluminum components gradually changed in a peak manner is arranged between the hole injection layer and the multi-quantum well layer.
2. The deep ultraviolet light emitting device with the double electron blocking layer according to claim 1, wherein: one side of the first electron blocking layer, which is in contact with the electron injection layer, is high Al component AlaGa1-aN, a is more than or equal to 0.4 and less than or equal to 0.9, and the side of the first electron barrier layer, which is in contact with the multi-quantum well layer, is low-Al component AlbGa1-bB is more than or equal to 0.3 and less than or equal to 0.9, the content of the Al component in the middle part is linearly reduced and changed, and the linear reduction gradient is a constant k1，k1In the range of 0<k1≤0.3。
3. The deep ultraviolet light emitting device with the double electron blocking layer according to claim 2, wherein: the thickness of the first electron barrier layer is 2-100 nm, the maximum value of the Al component content of the first electron barrier layer is larger than the Al component content of the electron injection layer, and the minimum value of the Al component content of the first electron barrier layer is equal to the Al component content of the multi-quantum well layer on the side close to the first electron barrier layer.
4. The deep ultraviolet light emitting device with the double electron blocking layer according to claim 1, wherein: the second electron blocking layer comprises an Al component increasing layer and an Al component decreasing layer which are sequentially arranged along the epitaxial growth direction, the Al component content of the junction of the Al component increasing layer and the Al component decreasing layer is equal, and the high Al component is arranged at the junction of the Al component increasing layer and the Al component decreasing layercGa1-cN，0.6≤c≤1。
5. The deep ultraviolet light emitting device with the double electron blocking layer according to claim 4, wherein: one side of the Al component increasing layer, which is in contact with the multi-quantum well layer, is low-Al component AldGa1-dD is more than or equal to 0.3 and less than or equal to 0.9, and the Al componentThe content of Al component in the middle part of the increment layer is changed in a linear increasing way, and the linear increasing gradient is a constant k2，k2In the range of 0<k2≤0.35。
6. The deep ultraviolet light emitting device with the double electron blocking layer according to claim 4, wherein: one side of the Al component decreasing layer, which is in contact with the hole injection layer, is low-Al component AleGa1-eN is more than or equal to 0.3 and less than or equal to 0.9, the content of the Al component in the middle part of the Al component increasing layer is linearly decreased and changed, and the linearly increasing gradient is a constant k3，k3In the range of 0<k3≤0.35。
7. The deep ultraviolet light emitting device with the double electron blocking layer according to claim 4, wherein: the thickness of the second electron blocking layer is set to be 5-50 nm, the thickness of the Al component increasing layer is set to be 2-30 nm, and the thickness of the Al component decreasing layer is set to be 2-30 nm; the Al component content of the side, close to the multi-quantum well layer, of the second electron barrier layer is equal to the Al component content of the side, close to the second electron barrier layer, of the multi-quantum well layer, and the Al component content of the side, close to the hole injection layer, of the second electron barrier layer is equal to the Al component content of the hole injection layer.
8. The deep ultraviolet light emitting device with the double electron blocking layer according to claim 1, wherein: the electron injection layer is arranged to be an n-AlGaN layer, and the composition material of the n-AlGaN layer is Si-doped AlxGa1-xX is more than or equal to 0.4 and less than or equal to 0.7, the thickness of the electron injection layer is set to be 500-3000 nm, and the doping concentration of Si is 1 x 1018～1*1020cm-3Electron concentration after doping is 1 x 1018～1*1020cm-3(ii) a The composition material of the multi-quantum well layer is AlyGa1-yY is more than or equal to 0.3 and less than or equal to 0.6, the multi-quantum well layer comprises AlGaN potential well layers with the thickness of 1-5 nm and AlGaN barrier layers with the thickness of 4-15 nm which are alternately grown, and the repetition period is 3-10; said air gapThe hole injection layer is arranged as a p-AlGaN layer, and the composition material of the p-AlGaN layer is Mg-doped AlzGa1-zZ is more than or equal to 0.5 and less than or equal to 0.7, the thickness of the hole injection layer is set to be 20-100 nm, and the concentration of Mg doping is 1 x 1018～1*1020cm-3。
9. The deep ultraviolet light emitting device with the double electron blocking layer according to claim 1, wherein: the light-emitting diode also comprises a substrate layer, a buffer layer I, an AlN intrinsic layer and a buffer layer II which are sequentially arranged from bottom to top, wherein the electron injection layer grows on the buffer layer II, and an N-type electrode is arranged on the electron injection layer; the hole injection layer is provided with a P-GaN layer, the P-GaN layer is provided with a P-type electrode, and the N-type electrode is connected with the P-type electrode in an ohmic contact mode.
10. A method for preparing a deep ultraviolet light emitting device with a double electron blocking layer according to any one of claims 1 to 9, wherein the method comprises the following steps: the method comprises the following steps:
step 1: sequentially growing a buffer layer I, an AlN intrinsic layer, a buffer layer II and an electron injection layer on a substrate;
step 2: linearly reducing the flow of the metal organic source TMAl along with the growth line, and growing a first electron blocking layer;
and step 3: growing a multi-quantum well layer on the first electron barrier layer;
and 4, step 4: the flow of TMAl which is a metal organic source is increased linearly along with the growth line and then is reduced, and a second electron blocking layer is grown;
and 5: sequentially growing a hole injection layer and a p-GaN layer on the second electron blocking layer;
step 6: and manufacturing an ohmic contact electrode on the electron injection layer and the p-GaN layer.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20150017241A (en) * | 2013-08-06 | 2015-02-16 | 엘지전자 주식회사 | Light emitting device |
| CN108630790A (en) * | 2018-05-24 | 2018-10-09 | 华南师范大学 | A kind of deep ultraviolet LED based on AlGaN |
| CN109346583A (en) * | 2018-08-31 | 2019-02-15 | 华灿光电（浙江）有限公司 | A kind of LED epitaxial slice and preparation method thereof |
| CN109659409A (en) * | 2018-12-05 | 2019-04-19 | 湖北深紫科技有限公司 | A kind of LED epitaxial structure and preparation method thereof |
| CN110112270A (en) * | 2019-05-10 | 2019-08-09 | 马鞍山杰生半导体有限公司 | Deep ultraviolet LED epitaxial wafer and preparation method thereof and deep ultraviolet LED |
| CN111599903A (en) * | 2020-06-23 | 2020-08-28 | 东南大学 | Ultraviolet LED with polarization-doped composite polar surface electron barrier layer |
-
2021
- 2021-12-28 CN CN202111683645.6A patent/CN114361308A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20150017241A (en) * | 2013-08-06 | 2015-02-16 | 엘지전자 주식회사 | Light emitting device |
| CN108630790A (en) * | 2018-05-24 | 2018-10-09 | 华南师范大学 | A kind of deep ultraviolet LED based on AlGaN |
| CN109346583A (en) * | 2018-08-31 | 2019-02-15 | 华灿光电（浙江）有限公司 | A kind of LED epitaxial slice and preparation method thereof |
| CN109659409A (en) * | 2018-12-05 | 2019-04-19 | 湖北深紫科技有限公司 | A kind of LED epitaxial structure and preparation method thereof |
| CN110112270A (en) * | 2019-05-10 | 2019-08-09 | 马鞍山杰生半导体有限公司 | Deep ultraviolet LED epitaxial wafer and preparation method thereof and deep ultraviolet LED |
| CN111599903A (en) * | 2020-06-23 | 2020-08-28 | 东南大学 | Ultraviolet LED with polarization-doped composite polar surface electron barrier layer |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115832136A (en) * | 2023-02-22 | 2023-03-21 | 江西兆驰半导体有限公司 | AlGaN-based ultraviolet light-emitting diode and preparation method thereof |
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