This application claims priority to Chinese Patent Application No. 201410510986.7 filed on Sep. 29, 2014, the contents of which are incorporated by reference herein.
The subject matter herein generally relates to a light emitting diode (LED), and also relates to a method for manufacturing the same.
A light emitting diode generally includes a substrate, an N semiconductor layer, a light emitting layer, and a P semiconductor layer arranged on the substrate in series. An N electrode is mounted on the N semiconductor layer, and a P electrode is mounted on the P semiconductor layer. While the LED is manufactured, a plurality of protrusions is firstly formed on the substrate, the N semiconductor layer, a light emitting layer and a P semiconductor layer are formed on the substrate.
Implementations of the present technology will now be described, by way of example only, with reference to the attached figures.
It will be appreciated that for simplicity and clarity of illustration, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure. The description is not to be considered as limiting the scope of the embodiments described herein.
The term “comprising” means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series and the like.
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The microstructure 11 can be a strip bended continuously, and includes a plurality of protruding portions 110 and a plurality of connecting portions 120 connecting to the protruding portions 110. A thickness of the strip along a length direction thereof can be uniform. The thickness of the strip along a length direction thereof is between 80 nm and 180 nm, in one example, the thickness of the strip along a length direction thereof is 120 nm. A plurality of void gaps 150 are sandwiched between the microstructure 11 and the substrate 10. Each void gap is surrounded by a corresponding protruding portion 110 and the substrate 10. Each protruding portion 110 includes a top wall 111 and two side walls 112 extending outward and downward from the top wall 111. Each void gap is defined by the top wall 111 and the two sides walls 112. A size of the protruding portion 110 gradually decreases from the first surface 101 of the substrate 10 to the connecting portion 120. Each bottom end of one of side walls 112 connects with a corresponding connecting portion 120. Two adjacent side walls 112 of each protruding portion 110 and one connecting portion 120 therebetween define a groove 130. Each top wall 111 is a flat plate.
In the illustrated embodiment, the microstructure 11 is made of Aluminum nitride (AlN). The top walls 111 of the protruding portion 110 are coplanar with each other. The connecting portions 120 of the microstructure 11 are also coplanar with each other. The microstructure 11 completely covers the first surface 101 of the substrate 10. The top walls 111 are parallel plate for reducing the stress between the microstructure 11 and the semiconductor layer 200 and improving quality of the LED. Further, the protruding portion 110 can reflect light emitted from the semiconductor layer 200 to improve the luminous efficiency of the LED.
A buffer layer 20 is filled in the groove 130 to cover the microstructure 11. The buffer layer 20 can reduce the lattice defects of an N semiconductor layer 30. A refractive index of the buffer 20 is greater than that of the microstructure 11.
The semiconductor layer 200 includes an N semiconductor layer 30, a light emitting layer 40 and a P semiconductor layer 50 mount on the buffer layer 20 of the base 100. An N electrode 31 is mounted on the N semiconductor layer 30, and a P electrode 51 is mounted on the P semiconductor layer 50. The P semiconductor layer 50 is made of Gallium nitride (GaN) and provides holes. The N semiconductor layer 30 is made of doped Gallium nitride (GaN) and provides electrons. The light emitting layer 40 gathers holes from the P semiconductor layer 50 and electrons from the N semiconductor layer 30 together to emit light.
In the illustrated embodiment, the microstructure 11 of the LED avoids the lattice defect density between the base 100 and the semiconductor layer 200. Also, the refractive index of the buffer layer 20 is greater than that of the microstructure 11 such that the light emitted from the light emitting layer 40 towards the base 100 can be totally reflected at the microstructure 11 to emit towards the direction away the base 100. Thus, the light exit from the second surface 102 of the base 100 is limited, and the light exit towards the P semiconductor layer 50 is increased to improve the luminous efficiency of the LED.
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The embodiments shown and described above are only examples. Many details are often found in the art such as the other features of a light emitting diode and method for manufacturing the same. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes can be made in the detail, including in matters of shape, size and arrangement of the parts within the principles of the present disclosure up to, and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above can be modified within the scope of the claims.
Number | Date | Country | Kind |
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201410510986.7 | Sep 2014 | CN | national |