阅读说明：本技术 红外发光二极管外延片及其制备方法和红外发光二极管 (Infrared light-emitting diode epitaxial wafer, preparation method thereof and infrared light-emitting diode ) 是由 高文浩 冯彦斌 梁倩 吴超瑜 彭钰仁 于 2021-08-27 设计创作，主要内容包括：本发明提供一种红外发光二极管外延片及其制备方法和红外发光二极管,其中,所述红外发光二极管外延片包括依次层叠的：n型欧姆接触层、n型覆盖层、发光层、p型覆盖层、p型GaInP过渡层、p型Al-(x)Ga-((1-x))InP过渡层及p型GaP欧姆接触层,其中,所述p型Al-(x)Ga-((1-x))InP过渡层中x的取值范围满足0＜x≤0.7。本发明通过在红外发光二极管外延片中的p型GaInP过渡层和p型GaP欧姆接触层之间增加一层p型Al-(x)Ga-((1-x))InP材料,解决了p型GaInP过渡层和p型GaP欧姆接触层之间存在较多缺陷且带隙差大的问题,减少红外发光二极管中的电流阻塞,增强红外发光二极管抗静电能力,降低红外发光二极管的结温及使用电压,进而提升红外发光二极管的电光转换效率和发光亮度,并延长器件的使用寿命。(The invention provides an infrared light-emitting diode epitaxial wafer, a preparation method thereof and an infrared light-emitting diode, wherein the infrared light-emitting diode epitaxial wafer comprises the following components in sequential stacking: n-type ohmic contact layer, n-type cladding layer, light emitting layer, p-type cladding layer, p-type GaInP transition layer, and p-type Al x Ga (1‑x) InP transition layer and p-type GaP ohmic contact layer, wherein the p-type Al x Ga (1‑x) The value range of x in the InP transition layer is more than 0 and less than or equal to 0.7. The invention adds a layer of p-type Al between a p-type GaInP transition layer and a p-type GaP ohmic contact layer in an infrared light-emitting diode epitaxial wafer x Ga (1‑x) InP material, p-type GaInP transition layer and p-type GaInP transition layerThe problems of more defects and large band GaP difference exist between GaP ohmic contact layers, the current blocking in the infrared light-emitting diode is reduced, the antistatic capability of the infrared light-emitting diode is enhanced, the junction temperature and the service voltage of the infrared light-emitting diode are reduced, the electro-optic conversion efficiency and the luminous brightness of the infrared light-emitting diode are further improved, and the service life of the device is prolonged.)

1. The utility model provides an infrared emitting diode epitaxial wafer which characterized in that, infrared emitting diode epitaxial wafer is including range upon range of in proper order: n-type ohmic contact layer, n-type cladding layer, light emitting layer, p-type cladding layer, p-type GaInP transition layer, and p-type Al_xGa_(1-x)InP transition layer and p-type GaP ohmic contact layer, wherein the p-type Al_xGa_(1-x)The value range of x in the InP transition layer is more than 0 and less than or equal to 0.7.

2. The infrared light emitting diode epitaxial wafer of claim 1, wherein: the p-type Al_xGa_(1-x)The value range of x in the InP transition layer is more than 0 and less than or equal to 0.6.

3. The infrared light emitting diode epitaxial wafer of claim 1, wherein: an n-type window layer is arranged between the n-type ohmic contact layer and the n-type covering layer, and a p-type window layer is arranged between the p-type covering layer and the p-type GaInP transition layer.

4. The infrared light emitting diode epitaxial wafer of claim 3, wherein: the n-type ohmic contact layer is made of GaAs, the n-type window layer is made of n-type doped AlGaAs, the n-type covering layer is made of n-type doped AlGaAs, the p-type covering layer is made of p-type doped AlGaAs, and the p-type window layer is made of p-type doped AlGaAs.

5. The method of claim 1Infrared emitting diode epitaxial wafer, its characterized in that: the p-type Al_xGa_(1-x)The thickness of the InP transition layer is less than 500 nm.

6. The infrared light emitting diode epitaxial wafer of claim 1, wherein: the p-type Al_xGa_(1-x)The content of Al component in the InP transition layer is along the p-type Al_xGa_(1-x)The growth direction of the InP transition layer is increased in a gradual change mode.

7. The infrared light emitting diode epitaxial wafer of claim 6, wherein: the p-type Al_xGa_(1-x)The InP transition layer comprises three layers of p-type Al_xGa_(1-x)An InP sublayer of Al in the order of growth_0.15Ga_0.85Sublayer of InP, Al_0.35Ga_0.65Sublayer of InP, Al_0.55Ga_0.45An InP sublayer.

8. The infrared light emitting diode epitaxial wafer of claim 1, wherein: the p-type Al_xGa_(1-x)The p-type doping element in the InP transition layer is Zn.

9. An infrared light emitting diode comprising the infrared light emitting diode epitaxial wafer as claimed in any one of claims 1 to 8.

10. A preparation method of an infrared light emitting diode epitaxial wafer is characterized by comprising the following steps:

1) providing a substrate;

2) growing an n-type ohmic contact layer on the substrate;

3) growing an n-type window layer on the n-type ohmic contact layer;

4) growing an n-type covering layer on the n-type window layer;

5) growing a light emitting layer on the n-type cladding layer;

6) growing a p-type cladding layer on the light emitting layer;

7) growing a p-type window layer on the p-type covering layer;

8) growing a p-type GaInP transition layer on the p-type window layer;

9) growing p-type Al on the p-type GaInP transition layer_xGa_(1-x)The value range of x of the InP transition layer satisfies that x is more than 0 and less than or equal to 0.7;

10) in the p-type Al_xGa_(1-x)And growing a p-type GaP ohmic contact layer on the InP transition layer.

11. The method for preparing an infrared light emitting diode epitaxial wafer according to claim 10, wherein the method comprises the following steps: in step 9), the p-type Al_xGa_(1-x)The content of Al component in the InP transition layer increases in a gradual mode during the growth process.

12. The method for preparing an infrared light emitting diode epitaxial wafer according to claim 11, wherein the method comprises the following steps: the p-type Al_xGa_(1-x)Al is formed in the InP transition layer in sequence during the growth process_0.15Ga_0.85Sublayer of InP, Al_0.35Ga_0.65Sublayer of InP, Al_0.55Ga_0.45An InP sublayer.

Technical Field

The invention relates to the technical field of light emitting diodes, in particular to an infrared light emitting diode epitaxial wafer, a preparation method thereof and an infrared light emitting diode.

Background

An infrared light emitting diode is an important light emitting device, and is widely applied to the fields of various photoelectric switches, remote control transmitting circuits, vehicle sensing and the like. The infrared light emitting diode epitaxial wafer is a basic structure for preparing an infrared light emitting diode, and the structural schematic diagram is shown in fig. 1, and the structure from bottom to top sequentially comprises: n-type ohmic contact layer 1, n-type window layer 2, n-type cladding layer 3, light-emitting layer 4, p-type cladding layer 5, p-type window layer 6, p-type GaInP transition layer 7 and p-type GaP ohmic contact layer 9.

Research shows that the band GaP difference between the AlGaAs structure and the GaP structure is large, so that the series resistance is quite high, the current is crowded at the GaInP transition layer, the operating voltage is further very high, the electro-optic conversion efficiency of the device is seriously reduced, and energy is wasted. Second, current crowding can cause the antistatic capability of the device to be greatly reduced. In addition, the increase of the series resistance increases the heat productivity of the device, thereby causing the increase of junction temperature, reducing the luminous brightness of the device and prolonging the service life.

Disclosure of Invention

In view of the above drawbacks of the prior art, an object of the present invention is to provide an infrared light emitting diode epitaxial wafer and a method for manufacturing the same, which are used to solve the problems of the prior art that there are many defects between a p-type GaInP transition layer and a p-type GaP ohmic contact layer and the band GaP difference is large.

In order to achieve the above and other related objects, the present invention provides an infrared light emitting diode epitaxial wafer, including: n-type ohmic contact layer and n-type capLayer, light-emitting layer, p-type cladding layer, p-type GaInP transition layer, p-type Al_xGa_(1-x)InP transition layer and p-type GaP ohmic contact layer, wherein the p-type Al_xGa_(1-x)The value range of x in the InP transition layer is more than 0 and less than or equal to 0.7.

Alternatively, the p-type Al_xGa_(1-x)The value range of x in the InP transition layer is more than 0 and less than or equal to 0.6.

Optionally, an n-type window layer is included between the n-type ohmic contact layer and the n-type cladding layer, and a p-type window layer is included between the p-type cladding layer and the p-type GaInP transition layer.

Optionally, the n-type ohmic contact layer is made of GaAs, the n-type window layer is made of n-type doped AlGaAs, the n-type cladding layer is made of n-type doped AlGaAs, the p-type cladding layer is made of p-type doped AlGaAs, and the p-type window layer is made of p-type doped AlGaAs.

Alternatively, the p-type Al_xGa_(1-x)The thickness of the InP transition layer is less than 500 nm.

Alternatively, the p-type Al_xGa_(1-x)The content of Al component in the InP transition layer is along the p-type Al_xGa_(1-x)The growth direction of the InP transition layer is increased in a gradual change mode.

Further, the p-type Al_xGa_(1-x)The InP transition layer comprises three layers of p-type Al_xGa_(1-x)An InP sublayer of Al in the order of growth_0.15Ga_0.85Sublayer of InP, Al_0.35Ga_0.65Sublayer of InP, Al_0.55Ga_0.45An InP sublayer.

Alternatively, the p-type Al_xGa_(1-x)The p-type doping element in the InP transition layer is Zn.

The invention provides an infrared light-emitting diode which comprises the infrared light-emitting diode epitaxial wafer.

The invention also provides a preparation method of the infrared light-emitting diode epitaxial wafer, which comprises the following steps:

1) providing a substrate;

2) growing an n-type ohmic contact layer on the substrate;

3) growing an n-type window layer on the n-type ohmic contact layer;

4) growing an n-type covering layer on the n-type window layer;

5) growing a light emitting layer on the n-type cladding layer;

6) growing a p-type cladding layer on the light emitting layer;

7) growing a p-type window layer on the p-type covering layer;

8) growing a p-type GaInP transition layer on the p-type window layer;

9) growing p-type Al on the p-type GaInP transition layer_xGa_(1-x)The value range of x of the InP transition layer satisfies that x is more than 0 and less than or equal to 0.7;

10) in the p-type Al_xGa_(1-x)And growing a p-type GaP ohmic contact layer on the InP transition layer.

Optionally, in step 9), the p-type Al_xGa_(1-x)The content of Al component in the InP transition layer increases in a gradual mode during the growth process.

Further, the p-type Al_xGa_(1-x)Al is formed in the InP transition layer in sequence during the growth process_0.15Ga_0.85Sublayer of InP, Al_0.35Ga_0.65Sublayer of InP, Al_0.55Ga_0.45An InP sublayer.

As described above, the infrared light emitting diode epitaxial wafer, the preparation method thereof and the infrared light emitting diode of the present invention have the following beneficial effects: adding a layer of P-type Al between a P-type GaInP transition layer and a P-type GaP ohmic contact layer in an infrared light-emitting diode epitaxial wafer_xGa_(1-x)InP material, Al_xGa_(1-x)InP can play a role in lattice constant transition on one hand, and reduces band GaP steepness between GaInP and GaP on the other hand. Thus, inserted Al_xGa_(1-x)The InP layer can reduce a large number of defects caused by interface mismatch, thereby reducing current blocking in the infrared light-emitting diode, enhancing the antistatic capability of the infrared light-emitting diode and reducing the infrared light-emitting diodeThe junction temperature and the use voltage of the tube further improve the electro-optic conversion efficiency and the luminous brightness of the infrared light-emitting diode and prolong the service life of the device.

Drawings

Fig. 1 is a schematic structural diagram of an infrared light emitting diode epitaxial wafer in the prior art.

Fig. 2 is a schematic structural diagram of an infrared light emitting diode epitaxial wafer according to the present invention.

Fig. 3 is a schematic structural diagram of another infrared light emitting diode epitaxial wafer according to the present invention.

Fig. 4 is a flow chart of a method for preparing an infrared light emitting diode epitaxial wafer according to the present invention.

Description of the element reference numerals

1 n type ohmic contact layer

2 n-type window layer

3 n type cladding layer

4 luminescent layer

41 InGaAs well layer

42 AlGaAs barrier layer

5 p-type cladding layer

6 p type window layer

7 p-type GaInP transition layer

8 p type Al_xGa_(1-x)InP transition layer

9 p type GaP ohmic contact layer

S1-S10

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than the number, shape and size of the components in actual implementation, and the type, amount, position relationship and proportion of the components in actual implementation can be changed freely on the premise of implementing the technical solution, and the layout of the components may be more complicated.

As shown in fig. 2, the present invention provides an infrared light emitting diode epitaxial wafer, which includes, stacked in sequence: n-type ohmic contact layer 1, n-type cladding layer 3, light emitting layer 4, p-type cladding layer 5, p-type GaInP transition layer 7, p-type Al_xGa_(1-x)An InP transition layer 8 and a p-type GaP ohmic contact layer 9, wherein the p-type Al_xGa_(1-x)The value range of x (the content of Al component) in the InP transition layer 8 is more than 0 and less than or equal to 0.7. Preferably, Al_xGa_(1-x)The value range of x in InP is more than 0 and less than or equal to 0.6.

The p-type GaInP transition layer 7 has a forbidden bandwidth of 1.87ev, the p-type GaP ohmic contact layer 9 has a forbidden bandwidth of 2.26ev, and the difference between the two gaps is large, so that direct contact with each other can generate a large number of defects due to interface mismatch, and the p-type Al transition layer_xGa_(1-x)The band gap range of the InP transition layer 8 is between 1.87ev and 2.26ev, and the p-type Al is ensured_xGa_(1-x)The InP transition layer 8 may be used to reduce the band GaP steepness between the p-type GaInP transition layer 7 and the p-type GaP ohmic contact layer 9, while reducing a large number of defects generated due to interface mismatch. Specifically, the p-type Al_xGa_(1-x)The content of Al component in the InP transition layer 8 is increased from bottom to top, and the p-type Al is_xGa_(1-x)The InP transition layer 8 can grow well on the p-type GaInP transition layer 7, and the p-type Al is ensured_xGa_(1-x)The InP transition layer 8 has fewer defects; the p-type GaP ohmic contact layer 9 is arranged on the p-type Al_xGa_(1-x)The InP transition layer 8 can also be grown on and ensure that the p-GaP ohmic contact layer 9 has fewer defects. Thereby reducingThe series resistance in the small infrared light-emitting diode reduces current blocking, enhances the antistatic capability of the infrared light-emitting diode, reduces the junction temperature and the service voltage of the infrared light-emitting diode, further improves the electro-optic conversion efficiency and the luminous brightness of the infrared light-emitting diode, and prolongs the service life of the device.

As an example, as shown in fig. 3, an n-type window layer 2 is included between the n-type ohmic contact layer 1 and the n-type cladding layer 3, and a p-type window layer 6 is included between the p-type cladding layer 5 and the p-type GaInP transition layer 7. The n-type window layer 2 and the p-type window layer 6 play a role in current expansion in the infrared light-emitting diode epitaxial wafer, and are beneficial to uniform distribution of current in the epitaxial wafer.

As an example, the p-type Al_xGa_(1-x)The thickness of the InP transition layer 8 is less than 500 nm. Preferably, the p-type Al_xGa_(1-x)The thickness of the InP transition layer 8 is 90 nm.

As an example, the p-type Al_xGa_(1-x)The content of Al component in the InP transition layer 8 is along the p-type Al_xGa_(1-x)The growth direction of the InP transition layer 8 increases in a gradual manner. Specifically, in the p-type Al_xGa_(1-x)In the InP transition layer 8, the content of Al component is along the p-type Al_xGa_(1-x)The growth direction of the InP transition layer 8 is gradually increased from 0 to x, wherein x is more than 0 and less than or equal to 0.7. Preferably, in said p-type Al_xGa_(1-x)In the InP transition layer 8, the content of Al component is along the p-type Al_xGa_(1-x)The growth direction of the InP transition layer 8 is increased gradually from 0 to 0.6. The p-type Al_xGa_(1-x)The InP transition layer 8 can be divided into a plurality of p-type Al layers which are sequentially laminated_xGa_(1-x)InP sublayer, preferably of said p-type Al_xGa_(1-x)The InP transition layer 8 comprises three layers of the p-type Al_xGa_(1-x)An InP sublayer of Al in the order of growth_0.15Ga_0.85Sublayer of InP, Al_0.35Ga_0.65Sublayer of InP, Al_0.55Ga_0.45An InP sublayer. Preferably, the p-type Al_xGa_(1-x)The thickness of the three sublayers of the InP transition layer 8 is 30 nm.

As an example, the p-type Al_xGa_(1-x)The p-type doping element in the InP transition layer 8 is Zn, and the doping concentration is preferably 2.00E 18.

As an example, as shown in fig. 3, the light emitting layer 4 includes an InGaAs well layer 41 and an AlGaAs barrier layer 42, and the AlGaAs barrier layer 42 is grown on the InGaAs well layer 41.

In the present invention, the n-type ohmic contact layer 1 may use GaAs, the n-type window layer 2 may use n-type doped AlGaAs, the n-type clad layer 3 may use n-type doped AlGaAs, and the AlGaAs in the n-type window layer 2 and the AlGaAs in the n-type clad layer 3 may have different relative proportions of Al and Ga; the p-type cladding layer 5 may use p-type doped AlGaAs, the p-type window layer 6 may use p-type doped AlGaAs, and the AlGaAs in the p-type cladding layer 5 and the AlGaAs in the p-type window layer 6 have different relative proportions of Al and Ga. The following table details the preferred values of the main materials and their related parameters of each layer in the structure of the infrared light emitting diode epitaxial wafer shown in fig. 2.

Function(s)	Material	Thickness (nm)	Doping concentration	Energy band width (ev)
					P-type ohmic contact layer	GaP:C	50	1.00E19	2.26
P-type transition layer 2	(Al0.34Ga0.66)0.46In0.54P:Zn	90	2.00E18	2.06
					P-type transition layer 1	Ga0.46In0.54P:Zn	30	2.00E18	1.87
P-type window layer	Al0.25Ga0.75As:C	3000	5.00E17	1.74
					P-type cladding layer	Al0.45Ga0.55As:C	400	1.00E18	1.98
Barrier layer of luminescent layer	Al0.25Ga0.75As	25	-	1.74
					Well layer of light emitting layer	InGaAs	6	-	1.29
N-type cladding layer	Al0.45Ga0.55As:Te	400	1.00E18	1.98
					N-type window layer	Al0.25Ga0.75As:Te	7000	5.00E17	1.74
N-type ohmic contact layer	GaAs:Si	60	2.00E18	1.42

In the table, the materials of the layers other than the light-emitting layer 4 are doped, and the doping element is represented by the chemical formula of the main material of each layer. In addition, the transition layer is used for realizing the transition of the lattice constant, and the invention adds (Al) between the p-type GaInP transition layer 7 and the p-type GaP ohmic contact layer 9_xGa_(1-x))_yIn_(1-y)The P transition layer reduces the stress between layers and does not influence the performance of the device. Of P-type transition layer 2 (Al)_xGa_(1-x))_yIn_(1-y)The value of y in P varies with the P-type doping concentration and type, with (Al)_xGa_(1-x))_yIn_(1-y)Growth of P with a change in y value, theVariation can ensure (Al)_xGa_(1-x))_yIn_(1-y)The lattice constant of P changes in the direction of the lattice constant of GaP, and preferably the inventors confirmed by xrd test (Al)_0.34Ga_0.66)_0.46In_0.54The diffraction peak of the P material is at the position of 300arcsec at the right side of the diffraction peak of the GaAs substrate layer. By adopting the infrared light-emitting diode epitaxial wafer of the embodiment, when the test current is 350mA, the forward voltage of the device is reduced by about 0.02V compared with the prior device.

The infrared light-emitting diode of the invention comprises the infrared light-emitting diode epitaxial wafer.

The present invention further provides a method for preparing an infrared light emitting diode epitaxial wafer, which can be used for preparing the infrared light emitting diode epitaxial wafer, and the beneficial effects achieved by the method can be seen from the above description, and are not described in detail below. As shown in fig. 4, the preparation method includes the steps of:

1) providing a substrate (for epitaxial growth);

2) growing an n-type ohmic contact layer on the substrate;

3) growing an n-type window layer on the n-type ohmic contact layer;

4) growing an n-type covering layer on the n-type window layer;

5) growing a light emitting layer on the n-type cladding layer;

6) growing a p-type cladding layer on the light emitting layer;

7) growing a p-type window layer on the p-type covering layer;

8) growing a p-type GaInP transition layer on the p-type window layer;

9) growing p-type Al on the p-type GaInP transition layer_xGa_(1-x)The value range of x of the InP transition layer satisfies that x is more than 0 and less than or equal to 0.7;

10) in the p-type Al_xGa_(1-x)And growing a p-type GaP ohmic contact layer on the InP transition layer.

It should be noted that the n-type window layer and the p-type window layer need to be matched with a chip manufacturing process, for example, by roughening the window layer, so as to improve the light extraction efficiency and improve the device performance.

As an example, in the above step 5), the light emitting layer 4 includes an InGaAs well layer 41 and an AlGaAs barrier layer 42, the InGaAs well layer 41 is grown on the n-type AlGaAs cladding layer 3, and the AlGaAs barrier layer 42 is grown on the InGaAs well layer 41.

As an example, in step 9), the p-type Al_xGa_(1-x)The InP transition layer 8 may be grown in a gradual increase in the Al content. The specific gradation method is discussed above and will not be described herein.

The preparation method of the infrared light-emitting diode comprises the preparation method of the infrared light-emitting diode epitaxial wafer.

In summary, the present invention provides an infrared light emitting diode epitaxial wafer, a method for manufacturing the same, and an infrared light emitting diode, wherein the infrared light emitting diode epitaxial wafer includes: n-type ohmic contact layer, n-type cladding layer, light emitting layer, p-type cladding layer, p-type GaInP transition layer, and p-type Al_xGa_(1-x)InP transition layer and p-type GaP ohmic contact layer, wherein the p-type Al_xGa_(1-x)The value range of x (the content of Al component) in the InP transition layer is more than 0 and less than or equal to 0.7. The infrared light-emitting diode epitaxial wafer, the preparation method thereof and the infrared light-emitting diode have the following beneficial effects: adding a layer of P-type Al between a P-type GaInP transition layer and a P-type GaP ohmic contact layer in an infrared light-emitting diode epitaxial wafer_xGa_(1-x)InP material, Al_xGa_(1-x)InP can play a role in lattice constant transition on one hand, and reduces band GaP steepness between GaInP and GaP on the other hand. Thus, inserted Al_xGa_(1-x)The InP layer can reduce a large number of defects caused by interface mismatch, so that current blocking in the infrared light-emitting diode is reduced, the antistatic capacity of the infrared light-emitting diode is enhanced, the junction temperature and the service voltage of the infrared light-emitting diode are reduced, the electro-optic conversion efficiency and the light-emitting brightness of the infrared light-emitting diode are improved, and the service life of the device is prolonged. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.