AlGaN-based ultraviolet LED epitaxial structure
Technical Field
The application relates to the technical field of LED luminescence, in particular to an AlGaN-based ultraviolet LED epitaxial structure.
Background
An LED is a semiconductor solid-state light emitting device, which uses a semiconductor P-N junction as a light emitting structure, gallium nitride is currently considered as a third generation semiconductor material, and a gallium nitride-based light emitting diode having an InGaN/GaN active region is currently considered as the most potential light emitting source. At present, a GaN-based blue light LED epitaxial structure generally includes a substrate, a buffer layer, a first semiconductor layer, a multiple quantum well light emitting layer, a last barrier layer, an electronic barrier layer and a second semiconductor layer, the multiple quantum well light emitting layer generally has an InGaN/GaN superlattice structure, and the electronic barrier layer has a P-type AlGaN structure, but since the refractive index of AlGaN material is lower than that of GaN and InGaN, light emitted from the multiple quantum well light emitting layer is easily totally reflected at an interface between the last barrier layer and the electronic barrier layer, resulting in poor light output efficiency.
In view of the above problems, no effective technical solution exists at present.
Disclosure of Invention
An object of the embodiment of the application is to provide an AlGaN-based ultraviolet LED epitaxial structure, which improves light output efficiency.
In a first aspect, an embodiment of the present application provides an AlGaN-based ultraviolet LED epitaxial structure, including:
a substrate;
a nitride heterostructure layer disposed on the substrate;
a diamond/nitride heterostructure layer disposed on the nitride heterostructure layer;
a nitride heterogeneous active region light emitting structure layer arranged on the diamond/nitride heterogeneous structure layer;
and the p-type nitride heterostructure layer is arranged on the nitride heterogeneous active region light-emitting structure layer.
The AlGaN-based ultraviolet LED epitaxial structure provided by the embodiment of the application is provided with the diamond/nitride heterostructure layer which is a diamond/nitride superlattice structure layer, so that the reflection of photons in an ultraviolet waveband can be improved by utilizing the refractive index difference of a superlattice, and the light output power and the reliability of an LED device are improved.
Optionally, in the AlGaN-based ultraviolet LED epitaxial structure according to the embodiment of the present application, the substrate is an n-type doped C material diamond single crystal substrate.
Optionally, in the AlGaN-based ultraviolet LED epitaxial structure according to the embodiment of the present application, the thickness of the substrate is between 200nm and 1 mm.
Optionally, in the AlGaN-based ultraviolet LED epitaxial structure according to the embodiment of the present application, the doping impurities of the substrate include phosphorus, nitrogen, and sulfur, and the doping concentration is 1010 cm-3To 1020cm-3In the meantime.
Optionally, in the AlGaN-based ultraviolet LED epitaxial structure according to the embodiment of the present application, the nitride heterostructure layer is a group III nitride heterostructure layer.
Optionally, in the AlGaN-based ultraviolet LED epitaxial structure according to the embodiment of the present application, the nitride heterostructure layer is an AlGaN/GaN heterostructure layer, epitaxially grows on the upper surface of the substrate, and is located between the substrate and the diamond/nitride heterostructure layer.
Optionally, in the AlGaN-based ultraviolet LED epitaxial structure according to the embodiment of the present application, a composition of Al in the nitride heterostructure layer is between 0 and 1.
Optionally, in the AlGaN-based ultraviolet LED epitaxial structure according to the embodiment of the present application, the thickness of the nitride heterostructure layer is between 10nm and 10 μm.
Optionally, in the AlGaN-based ultraviolet LED epitaxial structure according to the embodiment of the present application, the diamond/nitride heterostructure layer is a diamond/nitride superlattice structure layer, and the diamond/nitride superlattice structure layer is epitaxially grown on the surface of the nitride heterostructure layer and located between the nitride heterostructure layer and the nitride heterostructure active region light emitting structure layer, where the diamond is doped in an n-type manner, and the doping elements include phosphorus, nitrogen, and sulfur.
Optionally, in the AlGaN-based ultraviolet LED epitaxial structure according to the embodiment of the present application, the nitride in the diamond/nitride heterostructure layer is doped n-type, the doping element is Si element or Zn element, and the doping concentration is 1010 cm-3To 1020cm-3In the meantime.
The AlGaN-based ultraviolet LED epitaxial structure provided by the embodiment of the application is provided with the diamond/nitride heterostructure layer which is a diamond/nitride superlattice structure layer, so that the reflection of photons in an ultraviolet waveband can be improved by utilizing the refractive index difference of a superlattice, and the light output power and the reliability of an LED device are improved.
Additional features and advantages of the present application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the embodiments of the present application. The objectives and other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.
Fig. 1 is a schematic structural diagram of an AlGaN-based ultraviolet LED epitaxial structure according to an embodiment of the present disclosure.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present application without making any creative effort, shall fall within the protection scope of the present application.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Meanwhile, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance.
Referring to fig. 1, fig. 1 is a schematic structural diagram of an AlGaN-based ultraviolet LED epitaxial structure according to some embodiments of the present application, where the AlGaN-based ultraviolet LED epitaxial structure includes: a substrate 10, a nitride heterostructure layer 20, a diamond/nitride heterostructure layer 30, a nitride heterostructure active region light emitting structure layer 40, and a p-type nitride heterostructure layer 50. Wherein the nitride heterostructure layer 20 is disposed on the substrate 10; a diamond/nitride heterostructure layer 30 disposed on the nitride heterostructure layer 20; the nitride hetero-active region light emitting structure layer 40 is disposed on the diamond/nitride hetero-structure layer 30. The p-type nitride heterostructure layer 50 is disposed on the nitride hetero-active region light emitting structure layer 40.
Specifically, the substrate 10 is a diamond substrate, which may be, for example, an n-type doped C material diamond single crystal substrate. The thickness of the substrate 10 is between 200nm and 1mm, and may be, for example, 300nm or 500 nm. Of course, it is not limited thereto. Wherein the doping impurities of the substrate 10 comprise phosphorus, nitrogen and sulfur, and the doping concentration is 1010 cm-3To 1020cm-3In the meantime.
Wherein the nitride heterostructure layer 20 is a III-nitride heterostructure layer. Specifically, the nitride heterostructure layer 20 is an AlGaN/GaN heterostructure layer epitaxially grown on the upper surface of the substrate 10 between the substrate 10 and the diamond/nitride heterostructure layer 30. It is understood that the composition of Al in the nitride heterostructure layer is between 0 and 1. Wherein the thickness of the nitride heterostructure layer 20 is between 10nm and 10 μm. Of course, it is not limited thereto.
Wherein the diamond/nitride heterostructure layer 30 is a diamond/nitride superlattice structure layer that is epitaxially grown on the surface of the nitride heterostructure layer 20 between the nitride heterostructure layer 20 and the nitride hetero-active region light emitting structure layer 40. Wherein, the superlattice is doped with n-type impurities. The layer has the function of improving the reflection of photons in an ultraviolet band by utilizing the refractive index difference of the superlattice, so that the light output power and the reliability of the LED device are improved, and the application of the AlGaN-based ultraviolet LED device is finally promoted. Wherein, the diamond is doped in an n type, and the doping elements comprise phosphorus element, nitrogen element and sulfur element. Of course, it is not limited thereto, and other elements may be employed. Wherein the nitride in the diamond/nitride heterostructure layer 30 is doped n-type, and the doping element is Si element or Zn element, or both. With a doping concentration of 1010 cm-3To 1020cm-3In the meantime.
The nitride hetero-active region light emitting structure 40 is a group III nitride hetero-active region light emitting structure layer, and for example, an AlGaN/GaN hetero-active region light emitting structure may be used. Wherein the group III nitride in the AlGaN/GaN hetero-active region light-emitting structure is a p-type group III nitride hetero-structure in which the Al composition is 0 to 25%.
The AlGaN-based ultraviolet LED epitaxial structure provided by the embodiment of the application is provided with the diamond/nitride heterostructure layer which is a diamond/nitride superlattice structure layer, so that the reflection of photons in an ultraviolet waveband can be improved by utilizing the refractive index difference of a superlattice, and the light output power and the reliability of an LED device are improved.
In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.
The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.