Miniature light-emitting element and light-emitting equipment
By setting a target epitaxial layer with a high resistivity edge above and/or below the active light emitting layer of the micro-luminous emitting element, the problem of low external quantum efficiency caused by the edge effect of the micro-luminous emitting element is solved, and higher luminous performance and smaller edge effect.
Patent Information
- Application Number
- CN202411724184.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-02-18
AI Technical Summary
The edge effect of the micro-luminescent element leads to low external quantum efficiency, and the prior art is difficult to effectively reduce the edge effect without reducing the light emitting region of the active light emitting layer.
A target epitaxial layer is arranged above and/or below the active light emitting layer of the micro-luminous emitting element. The resistivity of the edge region of the target epitaxial layer is greater than that of other regions. Through this structure, the current flows through the edge of the micro-luminous emitting element and limits the current flows only through the active The intermediate region of the luminescent layer.
It effectively reduces the edge effect of the micro-luminous emitting element, improves the luminous performance, and does not reduce the luminous area of the active luminous emitting layer too much.
Smart Images
Figure CN119486401A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of LED technology, and in particular to a micro light-emitting element and a light-emitting device. Background Art
[0002] As the size of light-emitting components continues to shrink, the proportion of edge effects increases, which is one of the main reasons for the low external quantum efficiency EQE% (External Quantum Efficiency) of current micro-light-emitting components.
[0003] Therefore, how to reduce the edge effect of micro-light-emitting elements is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention
[0004] In view of the above problems, the present application provides a micro light-emitting element and a light-emitting device, which reduces the edge effect of the micro light-emitting element and improves the light-emitting performance of the micro light-emitting element. The specific scheme is as follows:
[0005] In a first aspect, the present application provides a micro-light emitting element, the micro-light emitting element comprising:
[0006] A first semiconductor layer, an active light-emitting layer, and a second semiconductor layer are sequentially stacked in a first direction; one of the first semiconductor layer and the second semiconductor layer is N-type doped, and the other semiconductor layer is P-type doped;
[0007] a target epitaxial layer located between the first semiconductor layer and the active light-emitting layer, and / or located between the second semiconductor layer and the active light-emitting layer;
[0008] The resistivity of the edge region of the target epitaxial layer is greater than the resistivity of other regions of the target epitaxial layer.
[0009] Preferably, in the above-mentioned micro-light-emitting element, the width of the edge region is less than 2 microns.
[0010] Preferably, in the above-mentioned micro-light-emitting element, the material of the target epitaxial layer is Al x In 1-x P, 0.65>x>0.5.
[0011] Preferably, in the above-mentioned micro-light-emitting element, the target epitaxial layer includes N layers of sub-epitaxial layers stacked in sequence in the first direction, N≥2, and N is a positive integer;
[0012] Wherein, in two adjacent sub-epitaxial layers, the widths of the edge regions are different.
[0013] Preferably, in the above-mentioned micro-light-emitting element, in the direction in which the active light-emitting layer points to the semiconductor layer, in the N-layer sub-epitaxial layer, the width of the edge region gradually increases or decreases;
[0014] The semiconductor layer is the first semiconductor layer or the second semiconductor layer.
[0015] Preferably, in the above-mentioned micro-light-emitting element, in the direction in which the active light-emitting layer points to the semiconductor layer, in the N-layer sub-epitaxial layer, the width of the edge region first increases and then decreases or first decreases and then increases;
[0016] The semiconductor layer is the first semiconductor layer or the second semiconductor layer.
[0017] Preferably, in the above-mentioned micro-light-emitting element, the target epitaxial layer is immersed in a mixed solution of hydrofluoric acid and phosphoric acid so that the resistivity of the edge region of the target epitaxial layer is greater than the resistance of other regions of the target epitaxial layer.
[0018] Preferably, in the above-mentioned micro-light-emitting element, the ratio of hydrofluoric acid to phosphoric acid in the mixed solution is 10:1.
[0019] Preferably, in the above-mentioned micro-light-emitting element, the time for which the target epitaxial layer is immersed in the mixed solution is in the range of 10s-15s.
[0020] A second aspect of the present application provides a light-emitting device, which includes the micro-light-emitting element described in any one of the above items.
[0021] By means of the above technical scheme, the present application provides a micro-light-emitting element and a light-emitting device, in which a target epitaxial layer is arranged above and / or below the active light-emitting layer, and the resistivity of the edge area of the target epitaxial layer is greater than the resistivity of other areas of the target epitaxial layer, so as to effectively suppress the current from flowing through the edge of the micro-light-emitting element, thereby achieving the purpose of limiting the current to flow only through the middle area of the active light-emitting layer, thereby reducing the edge effect of the micro-light-emitting element and improving the luminescence performance of the micro-light-emitting element. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and the originals and elements are not necessarily drawn to scale.
[0023] Figure 1 It is a schematic diagram of processing an epitaxial layer based on an ion placement method in the prior art;
[0024] Figure 2A schematic diagram of a partial structure of a micro light-emitting element provided by an embodiment of the present invention;
[0025] Figure 3 A partial structural schematic diagram of another micro-light emitting element provided by an embodiment of the present invention;
[0026] Figure 4 A partial structural schematic diagram of another micro-light emitting element provided by an embodiment of the present invention;
[0027] Figure 5 A partial structural schematic diagram of another micro-light emitting element provided by an embodiment of the present invention;
[0028] Figure 6 A partial structural schematic diagram of another micro-light emitting element provided by an embodiment of the present invention;
[0029] Figure 7 A partial structural schematic diagram of another micro-light emitting element provided by an embodiment of the present invention;
[0030] Figure 8 A partial structural schematic diagram of another micro-light emitting element provided by an embodiment of the present invention;
[0031] Fig. 9 A partial structural schematic diagram of another micro-light-emitting element provided in an embodiment of the present invention. DETAILED DESCRIPTION
[0032] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application. The terms used in the implementation mode of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. It is known to those skilled in the art that with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.
[0033] It should be noted that the directional words appearing in the present invention are based on the relative position relationship shown in the drawings and cannot be used as an absolute limitation to the present application.
[0034] During the invention of this application, it was found that some existing technologies use ion distribution on the surface to form the top epitaxial layer into a reverse polarity semiconductor, so as to minimize the current from flowing through the edge of the micro-light-emitting element to reduce the edge effect. However, the ion distribution method affects too large an area of the epitaxial layer from top to bottom, which greatly reduces the light-emitting area of the active light-emitting layer.
[0035] The ion placement method is to diffuse the desired doping element onto the semiconductor layer using an ion beam. When the doping ions diffuse into the epitaxial layer, an epitaxial layer doped with the desired element is formed. Figure 1 , Figure 1 The schematic diagram of the processing of the epitaxial layer based on the ion layout method in the prior art. The previously grown epitaxial layer is ion-laying-typed to lay the semiconductor layer above the active light-emitting layer, and the surrounding area is laid into a semiconductor layer of reverse polarity by means of a mask (for example, a P-type semiconductor layer is laid into an N-type semiconductor layer, or an N-type semiconductor layer is laid into a P-type semiconductor layer).
[0036] This design will prevent the current from flowing through the reversed area after it is turned on, thereby achieving the purpose of limiting the current flowing through the edge. However, this method will affect more epitaxial layer areas, which will reduce the light-emitting area of the active light-emitting layer and reduce the light-emitting performance of the micro-light-emitting element.
[0037] Based on this, the embodiments of the present invention provide a micro-light-emitting element and a light-emitting device, which solve the technical problems existing in the prior art, reduce the edge effect of the micro-light-emitting element, and improve the light-emitting performance of the micro-light-emitting element.
[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0039] refer to Figure 2 , Figure 2 A schematic diagram of a part of the structure of a micro light-emitting element provided by an embodiment of the present invention, referring to Figure 3 , Figure 3 A partial structural diagram of another micro-light emitting element provided in an embodiment of the present invention, referring to Figure 4 , Figure 4 A schematic diagram of a part of the structure of another micro-light emitting element provided by an embodiment of the present invention. The micro-light emitting element provided by an embodiment of the present invention includes:
[0040] A first semiconductor layer 11, an active light-emitting layer 12 and a second semiconductor layer 13 are sequentially stacked in a first direction; one of the first semiconductor layer 11 and the second semiconductor layer 12 is N-type doped, and the other is P-type doped.
[0041] A target epitaxial layer 14 is located between the first semiconductor layer 11 and the active light-emitting layer 12 , and / or is located between the second semiconductor layer 13 and the active light-emitting layer 12 .
[0042] The resistivity of the edge region AA of the target epitaxial layer 14 is greater than the resistivity of the other regions BB of the target epitaxial layer 14 .
[0043] Specifically, in the embodiment of the present invention, a target epitaxial layer 14 is arranged above and / or below the active light-emitting layer 12, and the resistivity of the edge region AA of the target epitaxial layer 14 is greater than the resistivity of other regions BB of the target epitaxial layer 14, that is, the edge region AA of the target epitaxial layer 14 is a high resistivity region, so as to effectively suppress the current from flowing through the edge of the micro-light-emitting element, thereby achieving the purpose of limiting the current to flow only through the middle region of the active light-emitting layer 12, thereby reducing the edge effect of the micro-light-emitting element and improving the luminous performance of the micro-light-emitting element. When the target epitaxial layer 14 is arranged above and below the active light-emitting layer 12, the technical effect that can be achieved by the technical solution of the present application can be made more significant.
[0044] It should be noted that in the embodiment of the present invention, the upper side of the active light-emitting layer 12 can be understood as the side of the active light-emitting layer 12 facing the second semiconductor layer 13 , and the lower side of the active light-emitting layer 12 can be understood as the side of the active light-emitting layer 12 facing the first semiconductor layer 11 .
[0045] In an optional embodiment of the present invention, the target epitaxial layer 14 is immersed in a mixed solution of hydrofluoric acid and phosphoric acid so that the resistivity of the edge region AA of the target epitaxial layer 14 is greater than the resistance of other regions BB of the target epitaxial layer 14 .
[0046] The ratio of hydrofluoric acid to phosphoric acid in the mixed solution is 10:1. The target epitaxial layer 14 is immersed in the mixed solution for a time range of 10s-15s. The width of the edge area AA is less than 2 microns.
[0047] Specifically, in the embodiment of the present invention, the material of the target epitaxial layer 14 includes but is not limited to Al x In 1-x P, 0.65>x>0.5, the thickness range of the target epitaxial layer 14 is 50 angstroms-200 angstroms. In the chip manufacturing process, the target epitaxial layer 14 can be immersed in a mixed solution of a specific proportion for a certain period of time, and the target epitaxial layer 14 reacts with the mixed solution, and a material with high resistivity will be formed from the outside to the inside. In other words, the edge area AA of a certain width of the target epitaxial layer 14 is a high resistivity area. Based on this structure, after the voltage is applied and turned on, the current can be effectively suppressed from flowing through the edge of the micro-light-emitting element, thereby achieving the purpose of limiting the current to flow only through the middle area of the active light-emitting layer 12, thereby reducing the edge effect of the micro-light-emitting element and improving the luminescence performance of the micro-light-emitting element.
[0048] Optionally, the ratio of hydrofluoric acid to phosphoric acid in the mixed solution is 10:1, and the material of the target epitaxial layer 14 is Al x In 1-xWhen the time range of immersion of P and the target epitaxial layer 14 in the mixed solution is 10s-15s, the width of the edge area AA with high resistivity can be less than 2 microns. Compared with the prior art, the technical solution of the present application does not reduce the light-emitting area of the active light-emitting layer 12 too much. While the edge effect of the micro-light-emitting element can be reduced, the light-emitting area of the active light-emitting layer 12 will not be reduced too much, thereby improving the light-emitting performance of the micro-light-emitting element.
[0049] It should be noted that the width of the high-resistivity edge region AA can be controlled by adjusting the ratio of hydrofluoric acid to phosphoric acid in the mixed solution, and / or the material of the target epitaxial layer 14, and / or the immersion time of the target epitaxial layer 14 in the mixed solution.
[0050] In an optional embodiment of the present invention, Figure 2-Figure 4 As shown, the micro-light emitting element further includes:
[0051] The first window layer 15 is located on a side of the first semiconductor layer 11 away from the active light-emitting layer 12 . The first window layer 15 and the first semiconductor layer 11 have the same doping type.
[0052] The second window layer 16 is located on a side of the second semiconductor layer 13 away from the active light emitting layer 12 . The second window layer 16 and the second semiconductor layer 13 have the same doping type.
[0053] Specifically, in the embodiment of the present invention, when the first semiconductor layer 11 is a P-type semiconductor layer, the first window layer 15 is a P-type window layer; when the second semiconductor layer 13 is an N-type semiconductor layer, the second window layer 16 is an N-type window layer.
[0054] In an optional embodiment of the present invention, reference Figure 5 , Figure 5 A partial structural diagram of another micro light-emitting element provided by an embodiment of the present invention. In the embodiment of the present invention, the target epitaxial layer 14 comprises N sub-epitaxial layers stacked in sequence in the first direction, where N≥2 and N is a positive integer.
[0055] Wherein, in two adjacent sub-epitaxial layers, the widths of the edge regions are different.
[0056] Specifically, in the embodiment of the present invention, N=2 is taken as an example for explanation (i.e., including the sub-epitaxial layer 141 and the sub-epitaxial layer 142). By adjusting the width of the edge area AA in different sub-epitaxial layers, the structural diversity of the micro-light-emitting elements is improved. The width of the edge area AA in the sub-epitaxial layer at different distances from the active light-emitting layer 12 is adjusted to minimize the edge effect of the micro-light-emitting elements, and the light emission angle of the micro-light-emitting elements can be controlled.
[0057] In an optional embodiment of the present invention, reference Figure 6 , Figure 6 A partial structural diagram of another micro-light emitting element provided in an embodiment of the present invention, referring to Figure 7 , Figure 7 A partial structural diagram of another micro light-emitting element provided by an embodiment of the present invention. In the embodiment of the present invention, in the direction where the active light-emitting layer 12 points to the semiconductor layer, in the N-layer sub-epitaxial layer, the width of the edge region AA gradually increases or decreases.
[0058] The semiconductor layer is the first semiconductor layer 11 or the second semiconductor layer 13 .
[0059] Specifically, in the embodiment of the present invention, N=3 is used as an example for description (ie, including the sub-epitaxial layer 141, the sub-epitaxial layer 142 and the sub-epitaxial layer 143). Figure 6 As shown in FIG. 1 , in the direction in which the active light-emitting layer 12 points to the first semiconductor layer 11, the width of the edge region AA in the three-layer sub-epitaxial layer gradually increases. Figure 6 As shown, in the direction from the active light emitting layer 12 to the second semiconductor layer 13 , the width of the edge region AA in the three-layer sub-epitaxial layer gradually increases.
[0060] like Figure 7 As shown, in the direction in which the active light-emitting layer 12 points to the first semiconductor layer 11, the width of the edge region AA in the three-layer sub-epitaxial layer gradually decreases. Figure 7 As shown, in the direction from the active light-emitting layer 12 to the second semiconductor layer 13 , the width of the edge region AA in the three-layer sub-epitaxial layer gradually decreases.
[0061] By adjusting the width of the edge area AA in different sub-epitaxial layers, the structural diversity of the micro-light-emitting elements is improved. The width of the edge area AA in the sub-epitaxial layer at different distances from the active light-emitting layer 12 is adjusted to minimize the edge effect of the micro-light-emitting elements, and the light output angle of the micro-light-emitting elements can also be controlled.
[0062] In an optional embodiment of the present invention, reference Figure 8 , Figure 8 A partial structural diagram of another micro-light emitting element provided in an embodiment of the present invention, referring to Fig. 9 , Fig. 9 A partial structural diagram of another micro-light emitting element provided by an embodiment of the present invention. In the embodiment of the present invention, in the direction in which the active light emitting layer 12 points to the semiconductor layer, in the N-layer sub-epitaxial layer, the width of the edge region AA increases first and then decreases or decreases first and then increases.
[0063] The semiconductor layer is the first semiconductor layer 11 or the second semiconductor layer 13 .
[0064] Specifically, in the embodiment of the present invention, N=3 is used as an example for description (ie, including the sub-epitaxial layer 141, the sub-epitaxial layer 142 and the sub-epitaxial layer 143). Figure 8 As shown, in the direction in which the active light-emitting layer 12 points to the first semiconductor layer 11, the width of the edge region AA in the three-layer sub-epitaxial layer first increases and then decreases. Figure 8 As shown, in the direction in which the active light-emitting layer 12 points to the second semiconductor layer 13 , the width of the edge region AA in the three-layer sub-epitaxial layer increases first and then decreases.
[0065] like Fig. 9 As shown, in the direction in which the active light-emitting layer 12 points to the first semiconductor layer 11, the width of the edge region AA in the three-layer sub-epitaxial layer first decreases and then increases. Fig. 9 As shown, in the direction in which the active light-emitting layer 12 points to the second semiconductor layer 13 , the width of the edge region AA in the three-layer sub-epitaxial layer first decreases and then increases.
[0066] By adjusting the width of the edge area AA in different sub-epitaxial layers, the structural diversity of the micro-light-emitting elements is improved. The width of the edge area AA in the sub-epitaxial layer at different distances from the active light-emitting layer 12 is adjusted to minimize the edge effect of the micro-light-emitting elements, and the light output angle of the micro-light-emitting elements can also be controlled.
[0067] In summary, the technical solution of the present application can improve the luminescence performance of micro-light-emitting elements with minimal impact on the epitaxial layer while reducing the edge effect. Taking into account the problem of reduced chip luminescence efficiency due to non-radiative recombination effects of chip sidewall process material defects, the technical solution of the present application forms voids near the sidewalls so that electrons cannot flow to the sidewalls, thereby blocking the electron flow path, thereby achieving the performance of luminescence in the effective area of the electrons and limited path. Unlike other methods, the process involved in the technical solution of the present application is simple, and has mass production and process flexibility.
[0068] Based on the above embodiment of the present invention, a light-emitting device is provided in another embodiment of the present invention. The light-emitting device includes the micro-light-emitting element described in the above embodiment.
[0069] The above is a detailed introduction to a micro-light-emitting element and a light-emitting device provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technicians in this field, according to the idea of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.
[0070] It should be noted that each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.
[0071] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device that includes a series of elements is inherent to the elements, or also includes elements inherent to these processes, methods, articles or devices. In the absence of further restrictions, the elements defined by the sentence "including a..." do not exclude the presence of other identical elements in the process, method, article or device that includes the elements.
[0072] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A micro light-emitting element, characterized in that: The micro-light emitting element comprises: A first semiconductor layer, an active light-emitting layer, and a second semiconductor layer are sequentially stacked in a first direction; one of the first semiconductor layer and the second semiconductor layer is N-type doped, and the other semiconductor layer is P-type doped; a target epitaxial layer located between the first semiconductor layer and the active light-emitting layer, and / or located between the second semiconductor layer and the active light-emitting layer; The resistivity of the edge region of the target epitaxial layer is greater than the resistivity of other regions of the target epitaxial layer.
2. The micro-light emitting element according to claim 1, characterized in that: The width of the edge region is less than 2 microns.
3. The micro-light emitting element according to claim 1, characterized in that: The material of the target epitaxial layer is Al x In 1- x P, 0.65>x>0.
5.
4. The micro-light emitting element according to claim 1, characterized in that: The target epitaxial layer includes N sub-epitaxial layers stacked in sequence in the first direction, where N≥2 and N is a positive integer; Wherein, in two adjacent sub-epitaxial layers, the widths of the edge regions are different.
5. The micro-light emitting element according to claim 4, characterized in that: In the direction from the active light-emitting layer to the semiconductor layer, in the N-layer epitaxial layer, the width of the edge region gradually increases or decreases; The semiconductor layer is the first semiconductor layer or the second semiconductor layer.
6. The micro-light emitting element according to claim 4, characterized in that: In the direction from the active light-emitting layer to the semiconductor layer, in the N-layer sub-epitaxial layer, the width of the edge region first increases and then decreases, or first decreases and then increases; The semiconductor layer is the first semiconductor layer or the second semiconductor layer.
7. The micro-light emitting element according to any one of claims 1 to 6, characterized in that: The target epitaxial layer is immersed in a mixed solution of hydrofluoric acid and phosphoric acid, so that the resistivity of the edge region of the target epitaxial layer is greater than the resistance of other regions of the target epitaxial layer.
8. The micro-light emitting element according to claim 7, characterized in that: The ratio of hydrofluoric acid to phosphoric acid in the mixed solution is 10:
1.
9. The micro-light emitting element according to claim 8, characterized in that: The target epitaxial layer is immersed in the mixed solution for a time ranging from 10s to 15s.
10. A light emitting device, characterized in that: The light emitting device comprises the micro-light emitting element according to any one of claims 1-9.