CN204257687U - A kind of light emitting diode construction - Google Patents

Abstract

The utility model proposes a light-emitting diode structure, which is provided with a rough groove structure in the N electrode area, thereby increasing the light-emitting area, changing the critical angle of total reflection, and reducing the occurrence of total reflection, so as to improve the light extraction of the light-emitting diode Efficiency: By forming the N electrode on the groove structure with rough surface, the contact area between the electrode and the groove structure can be increased, thereby increasing the adhesion of the electrode and improving the reliability of the light emitting diode.

Description

A light emitting diode structure

technical field

The utility model relates to the technical field of semiconductors, in particular to a light emitting diode structure which can increase the light output area and improve the light extraction efficiency.

Background technique

Light Emitting Diode (English for Light Emitting Diode, LED for short) is a kind of semiconductor diode, which can convert electrical energy into light energy, and emit visible light of various colors such as yellow, green, and blue, as well as infrared and ultraviolet invisible light.

As shown in FIG. 1 , in a conventional front-mount light-emitting diode structure, it includes a substrate 100, an N-type layer 101 stacked from bottom to top, a light-emitting region 102, a P-type layer 103, a current spreading layer 105, a P-electrode 106, and an exposed N-electrode 106 on the surface of N-type layer 107 . Since the N electrode region 107 has a planar structure, it is not conducive to light extraction, and a smooth surface will increase the probability of total reflection, which limits the light extraction efficiency.

Contents of the invention

In order to solve the above-mentioned problems in the prior art, the utility model proposes a light emitting diode structure.

The technical solution adopted by the utility model to solve the technical problem is: a light-emitting diode structure, including: a light-emitting epitaxial layer composed of a first semiconductor layer, a second semiconductor layer and a quantum well layer sandwiched between the two layers, and The P electrode on the second semiconductor layer and the N electrode on the first semiconductor layer are characterized in that: the N electrode region is provided with a rough groove structure.

Preferably, the groove structure is wide at the top and narrow at the bottom.

Preferably, the rough surface of the groove structure is composed of several concave/convex lenses.

Preferably, the concave/convex lenses are distributed regularly or randomly.

Preferably, the groove structure penetrates down to the inside of the first semiconductor layer along the surface of the second semiconductor layer.

Preferably, the groove structure is only formed on the first semiconductor layer.

Preferably, a current spreading layer is formed between the P electrode and the light emitting epitaxial layer.

Preferably, the light-emitting epitaxial layer is a gallium nitride-based semiconductor layer, and the wavelength of light emitted by it is less than 500nm.

Compared with the prior art, the beneficial effects of the utility model include and are not limited to:

The utility model is provided with a rough groove structure in the N electrode area, thereby increasing the luminous area, changing the critical angle of total reflection, and reducing the occurrence of total reflection, so as to improve the light extraction efficiency of the light-emitting diode; Forming the N electrode on the groove structure can increase the contact area between the electrode and the groove structure, thereby increasing the adhesion of the electrode and improving the reliability of the light emitting diode.

Other features and advantages of the present invention will be set forth in the following description, and, in part, will be apparent from the description, or can be learned by practicing the present invention. The objectives and other advantages of the utility model can be realized and obtained by the structures particularly pointed out in the specification, claims and accompanying drawings.

Description of drawings

The accompanying drawings are used to provide a further understanding of the utility model, and constitute a part of the description, and are used to explain the utility model together with the embodiments of the utility model, and do not constitute a limitation to the utility model. In addition, the drawing data are descriptive summaries and are not drawn to scale.

FIG. 1 is a schematic cross-sectional view of a conventional front-mounted gallium nitride-based light-emitting diode structure.

FIG. 2 is a schematic cross-sectional view of the structure of a GaN-based light-emitting diode according to Embodiment 1 of the present invention.

FIG. 3 is an enlarged schematic view of the groove structure in FIG. 2 .

FIG. 4 is a schematic diagram of the groove structure of the GaN-based light-emitting diode structure according to Embodiment 2 of the present invention.

The symbols in the figure indicate: 100, 200: substrate; 101, 201: N-type layer; 102, 202: quantum well layer; 103, 203: P-type layer; 104, 204: current spreading layer; 105, 205: P electrode ; 106, 206: N-electrode; 107, 207: N-electrode region; 208: groove structure.

Detailed ways

The implementation of the utility model will be described in detail below in conjunction with the accompanying drawings and examples, so as to fully understand and implement the implementation process of how to apply technical means to solve technical problems and achieve technical effects in the utility model. It should be noted that, as long as there is no conflict, each embodiment and each feature in each embodiment of the utility model can be combined with each other, and the formed technical solutions are all within the protection scope of the utility model.

The implementation of the utility model will be described in detail below in conjunction with the accompanying drawings and examples, so as to fully understand and implement the implementation process of how to apply technical means to solve technical problems and achieve technical effects in the utility model.

Example 1

As shown in Figure 2, a positive light-emitting diode structure includes a substrate 200, a first semiconductor layer (N-type layer) 201, a second semiconductor layer (P-type layer) 203, and a quantum well sandwiched between the two layers. Layer 202 consists of a light emitting epitaxial layer, a current spreading layer 204 on the P-type layer 203 , a P electrode 205 on the current spreading layer 204 , and an N electrode 206 on the N-type layer 201 .

The above-mentioned light-emitting epitaxial layer can be deposited on the growth substrate 200 by using metal organic compound chemical vapor deposition (MOCVD for English abbreviation) or bonded on the heat-dissipating substrate 200 by flip-chip technology. The above-mentioned light-emitting diode is a blue-light light-emitting diode, and the material of the light-emitting epitaxial layer is a GaN-based compound. Generally, the electrodes can be directly formed on the light-emitting epitaxial layer or formed on the current spreading layer on the light-emitting epitaxial layer, and are used to connect to an external power source to stimulate the P-N junction to emit light.

In this embodiment, the substrate 200 is preferably sapphire, and the current spreading layer 204 is preferably ITO (indium tin oxide compound); on the sapphire substrate 200 and the N-type layer 201, a buffer layer known in the prior art and an undoped nitrogen layer can also be formed. Gallium oxide layer, etc.; the SiO ₂ current blocking layer commonly used in the prior art can also be formed on the P-type layer 203 and the current spreading layer 204 .

As shown in FIG. 3, in this embodiment, the N electrode region 207 is provided with a groove structure 208 with a wide top and a narrow bottom. The surface of the groove structure is rough and consists of several irregular (randomly distributed) concave lenses. , which is formed by etching down the surface of the second semiconductor layer into the interior of the first semiconductor layer.

After the groove structure 208 is formed, a P electrode 205 and an N electrode 206 are respectively formed on the current spreading layer 204 and the N-type layer 201 on the groove structure 208, so as to realize electrical coupling between the P and N electrodes and the light-emitting epitaxial layer.

As shown in the schematic diagram of the optical path in Figure 2, since the N electrode area is provided with a rough groove structure, that is, the area of several concave lenses is increased compared with the conventional flat smooth structure, so when the light emitting epitaxial layer emits the light source, the light source passes through each of the The surface of the concave lens emits light to increase the light-emitting area; in addition, due to the rough groove structure on the surface, the critical angle of total reflection is changed, which reduces the occurrence of total reflection, so as to improve the light extraction efficiency of the light-emitting diode; moreover, through the rough surface Forming the N electrode on the groove structure can increase the contact area between the electrode and the groove structure, thereby increasing the adhesion of the electrode and improving the reliability of the light emitting diode.

Example 2

As shown in Figure 4, different from Embodiment 1, the groove structure 208 of this embodiment is only formed on the first semiconductor layer (N-type layer) 101, and the surface of the groove structure consists of several periodic arrays (regularly distributed ) Concave lens composition.

To sum up, the design spirit of the light emitting diode structure of the present invention lies in: by providing a rough groove structure in the N electrode area, the light emitting area is increased, the critical angle of total reflection is changed, and light loss is reduced, so as to improve light emission. The light extraction efficiency of the diode; by forming the N electrode on the groove structure with rough surface, the contact area between the electrode and the groove structure can be increased, thereby increasing the adhesion of the electrode and improving the reliability of the light emitting diode.

Obviously, the description of the present utility model should not be construed as only being limited to the above-mentioned embodiments, but includes all implementations utilizing the concept of the present utility model.

Claims (8)

1. A light-emitting diode structure, comprising: a light-emitting epitaxial layer composed of a first semiconductor layer, a second semiconductor layer and a quantum well layer sandwiched between the two layers, and a P electrode positioned on the second semiconductor layer, positioned on the second semiconductor layer An N electrode on a semiconductor layer is characterized in that: the N electrode region is provided with a rough groove structure. 2 . The LED structure according to claim 1 , wherein the groove structure is wide at the top and narrow at the bottom. 3. The light emitting diode structure according to claim 1, wherein the rough surface of the groove structure is composed of several concave/convex lenses. 4 . The LED structure according to claim 3 , wherein the concave/convex lenses are distributed regularly or randomly. 5 . The light emitting diode structure according to claim 1 , wherein the groove structure penetrates downwardly from the surface of the second semiconductor layer to the inside of the first semiconductor layer. 5 . 6 . The light emitting diode structure according to claim 1 , wherein the groove structure is only formed in the first semiconductor layer. 7 . The light emitting diode structure according to claim 1 , wherein a current spreading layer is formed between the P electrode and the light emitting epitaxial layer. 8 . The light emitting diode structure according to claim 1 , wherein the light emitting epitaxial layer is a GaN-based semiconductor layer, and the wavelength of light emitted by it is less than 500 nm.