TW201407815A - AC light-emitting device - Google Patents

Abstract

An alternating current (AC) light-emitting device includes light-emitting units located on a substrate. Each light-emitting unit includes a first light-emitting sub-unit, a second light-emitting sub-unit and a tunnel junction layer. The tunnel junction layer is located between the first light-emitting sub-unit and the second light-emitting sub-unit to electrically couple the first light-emitting sub-unit and the second light-emitting sub-unit. The AC light-emitting device also includes at least one conductive layer that electrically connects the light-emitting units to drive the first and the second light-emitting sub-units of the same light-emitting unit in turn for each positive/negative half-cycle of an AC power.

Description

AC illuminator

The present invention relates to an alternating current lighting device, and more particularly to an alternating current lighting device using a vertically stacked epitaxial structure.

The AC LED module can be directly driven by AC power without the need for a DC voltage converter. During the positive half cycle, part of the light-emitting diode will conduct light, while the other part of the light-emitting diode will not conduct; in the negative half cycle, the light-emitting diode will be turned on exactly the opposite.

The AC LED module is generally designed with a planar array, that is, all the LEDs are disposed adjacent to each other in the horizontal direction. At a certain point in time, only part of the light-emitting diodes are lit, and the other part is idle, so that the average light-emitting brightness cannot be increased, or the circuit area is wasted.

Therefore, it is urgent to propose a novel AC illuminating device for improving the illuminating brightness or reducing the circuit area.

In view of the above, embodiments of the present invention provide an alternating current illuminating device that uses a vertically stacked epitaxial structure of light emitting cells and uses a tunneling junction layer to electrically couple vertically adjacent epitaxial structures.

According to an embodiment of the invention, an alternating current lighting device includes a substrate, a plurality of light emitting units, and at least one conductive layer. The light emitting units are respectively disposed on the substrate, and each of the light emitting units includes a first light emitting sub-unit, a second light emitting sub-unit, and a tunneling junction layer. The tunneling junction layer is located between the first illuminating sub-unit and the second illuminating sub-unit for electrically coupling the first illuminating sub-unit and the second illuminating sub-unit. The conductive layer is electrically connected to the light-emitting units such that the first light-emitting sub-unit and the second light-emitting sub-unit of the same light-emitting unit are alternately driven to emit light according to the driving of the positive and negative half-cycle voltages of the alternating current power source.

1A through 1D show an AC illumination device 100 according to a first embodiment of the present invention, wherein the first A diagram and the first B diagram respectively show a cross section of the AC illumination device 100 when it is driven by a positive half cycle voltage of an AC power source. The figure and the equivalent circuit diagram, the first C picture and the first D picture respectively show a cross-sectional view and an equivalent circuit diagram when the AC light-emitting device 100 is driven by the negative half-cycle voltage of the AC power source.

As shown in FIG. A, the AC light-emitting device 100 includes a plurality of light-emitting units 1 (six shown) on the substrate 10 (either formed on the substrate 10 or replaced with a substrate). Each of the illuminating units 1 includes a first illuminating sub-unit 11 and a second illuminating sub-unit 12 that are vertically stacked, and a tunneling junction layer 13 between the first illuminating sub-unit 11 and the second illuminating sub-unit 12 for The first illuminating sub-unit 11 and the second illuminating sub-unit 12 are electrically coupled.

The first illuminating sub-unit 11 includes at least one epitaxial structure (ie, a light emitting diode), and each ㄧ epitaxial structure includes a first doping layer 111, a luminescent layer 112, and a second doping layer 113, wherein the luminescent layer 112 The first doped layer 111 is electrically opposite to the second doped layer 113 (for example, the first doped layer 111 is n-type doped, The two doped layer 113 is p-type doped, and may be the opposite case). In a similar manner, the second illuminating sub-unit 12 includes at least one epitaxial structure, and each ㄧ epitaxial structure includes a first doping layer 121, a luminescent layer 122, and a second doping layer 123, wherein the luminescent layer 122 is located in the first doping Between the impurity layer 121 and the second doping layer 123, and the electrical properties of the first doping layer 121 and the second doping layer 123 are opposite (for example, the first doping layer 121 is n-type doped, the second doping layer 123 is p-type doping, and the opposite can also be the case). Thereby, the tunnel junction layer 13 is electrically coupled to the second doping layer 113 of the first illuminating sub-unit 11 and the first doping layer 121 of the second illuminating sub-unit 12 .

The first illuminating sub-unit 11 and the second illuminating sub-unit 12 shown in FIG. 1A each include an epitaxial structure, but the first illuminating sub-unit 11 or the second illuminating sub-unit 12 may also include a plurality of epitaxial structures. Used to achieve the desired forward bias or desired illuminance. The second figure illustrates another illumination unit 1 of FIG. A, wherein the first illumination sub-unit 11 includes two epitaxial structures 11A and 11B, and the tunnel junction layer 11C is used between the two epitaxial structures 11A and 11B. Electrical coupling.

In this embodiment, as shown in FIG. A, there are two types of electrical connections between adjacent light-emitting units 1. The first type of electrical connection is a parallel electrical connection type for electrically connecting the adjacent intermediate nodes of the adjacent two illumination units 1 (such as the left and left illumination units shown in FIG. A). The term "intermediate node" as used herein refers to a region in which the first illuminating subunit 11 and the second illuminating subunit 12 are electrically coupled to each other, such as the second doping layer 113 and the second of the first illuminating subunit 11. The first doped layer 121 of the illuminating sub-unit 12 is electrically coupled to each other by the tunnel junction layer 13. The second electrical connection type is a crossover electrical connection type for electrically charging all external electrodes of the adjacent two illumination units 1 (such as the left and left illumination units shown in FIG. The term "external electrode" as used in this specification refers to an electrode that is in contact with the doped layer of the first/second illuminating subunit 11/12 closest to the outside (or farthest from the tunneling junction layer 13). For example, the electrode 124 that is in contact with the second doping layer 123 of the second illuminating subunit 12, or the electrode 114 that is in contact with the first doping layer 111 of the first illuminating subunit 11. As for the electrode in contact with other doped layers, it is referred to as "internal electrode" in this specification. The above-described parallel electrical connection type and interleaved electrical connection type are alternately used between adjacent light-emitting units 1, thereby forming the parallel alternating current light-emitting device 100 of the present embodiment.

The first electrical connection type (that is, the parallel electrical connection type) has the following implementation structures. As shown in FIG. 3A, the first conductive layer 14 is used to electrically connect the adjacent two light-emitting units 1 to the corresponding doped layers of the intermediate nodes (for example, the first doped layer 121 of the second light-emitting sub-unit 12 is illustrated). coupling. In another variant embodiment (as shown in FIG. 3B), the first conductive layer 14 is further electrically coupled by the internal electrodes of the first doped layer 121 of the adjacent second illuminating sub-units 12. A region between the adjacent two light-emitting units 1 under the first conductive layer 14 is filled with a first insulating layer 15, which may be made of a polymer, a ceramic material such as cerium oxide, or any combination thereof. In an example of the present embodiment, the first insulating layer 15 is a polymer, and has a gap filling property to form a uniform thickness (without voids). In addition, the cross-sectional shape of the first conductive layer 14 and the first insulating layer 15 is not necessarily rectangular, and may be a polygonal cross section, as shown in FIG. 3C. The third D diagram shows another implementation of the first electrical connection type. In the present embodiment, the first conductive layer 14 electrically couples the adjacent doped layers of the adjacent two light emitting units 1 at the intermediate nodes (for example, the second doped layer 113 of the first light emitting sub-unit 11).

The implementation structure of the second electrical connection type (that is, the interleaved electrical connection type) is as shown in FIG. 1A, and the second conductive layer 16 is used to connect the adjacent two light-emitting units 1 (as shown in FIG. All (four of the total) external electrodes 114 and 124 of the second and left third light-emitting units are electrically connected. Further, a second insulating layer 17 is included between the second conductive layer 16 and the sidewall of the light emitting unit 1.

In an example of this embodiment, the tunnel junction layer 13 comprises a group of four elements and a nitrogen element, that is, a compound composed of at least one group of four elements and a nitrogen element, and the group of elements and atoms of the nitrogen element The number accounts for more than 50% of the total atomic percentage of the tunneling junction layer. In another example of the embodiment, the tunnel junction layer 13 can be processed at a low temperature (for example, 400 to 1000 ° C), and the formation temperature is lower than the adjacent epitaxial structure (for example, the first illumination sub-unit 11 and the second illumination sub-unit). 12) Formation temperature.

In still another example of this embodiment, the tunnel junction layer 13 can be a defect-induced structure that provides a defect density greater than a defect of the growth layer (ie, the bottom of the tunnel junction layer 13). More than five times the density.

In still another example of this embodiment, the tunnel junction layer 13 may have a multi-layer structure, preferably having a thickness of less than or equal to 30 nm. The tunneling junction layer 13 may be undoped or have a doping concentration that is less than a doping concentration of adjacent epitaxial structures (eg, the first illuminating sub-element 11 and the second illuminating sub-element 12). In still another example of this embodiment, the tunnel junction layer 13 may be doped with carbon, and its doping concentration is greater than 10 ¹⁷ atoms/cm 3 , and preferably ranges from 10 ¹⁸ to 10 ²⁰ atoms/cm 3 .

4A to 4D are diagrams showing an AC illumination device 400 according to a second embodiment of the present invention, wherein the fourth A diagram and the fourth B diagram respectively show a cross section of the AC illumination device 400 when it is driven by a positive half cycle voltage of an AC power source. The figure and the equivalent circuit diagram, the fourth C picture and the fourth D picture respectively show a cross-sectional view and an equivalent circuit diagram when the AC light-emitting device 400 is driven by the negative half-cycle voltage of the AC power source.

As shown in FIG. 4A, the AC light-emitting device 400 includes a plurality of light-emitting units 1 (three shown) which are respectively disposed on the substrate 10 (either epitaxially formed on the substrate 10 or replaced with a substrate). The structure of each of the light-emitting units 1 is similar to that of the first embodiment, and therefore the same reference numerals are used, and the details thereof will not be described again.

In this embodiment, as shown in FIG. 4A, the electrical connection between the adjacent light-emitting units 1 is a series/parallel electrical connection type for using a light-emitting unit 1 (as shown in FIG. 4A). The external electrodes 114 and 124 of the first and second illuminating sub-units 11 and 12 of the left second illuminating unit are connected in series, and are adjacent to the adjacent illuminating unit 1 (such as the left illuminating unit shown in FIG. 4A). The internal electrodes 125 of the nodes are connected in parallel. As shown in FIG. 4A, the external electrodes 114 and 124 are connected in series and are connected in parallel to the internal electrodes 125 which are in contact with the first doping layer 121 of the second illuminating sub-unit 12. The fifth figure shows another variant embodiment in which the external electrodes 114 and 124 are connected in series and the internal electrodes 115 in contact with the second doping layer 113 of the first illuminating sub-unit 11 are connected in parallel.

In the present embodiment, as shown in FIG. 4A or FIG. 5, the external electrodes 114, 124 of one light-emitting unit 1 are electrically coupled to the internal electrodes 125 or 115 of the adjacent light-emitting units 1 using the conductive layer 18. In other words, there are (only) three electrodes (ie, two external electrodes and one internal electrode) electrically coupled to each other between adjacent light-emitting units 1. Further, an insulating layer 19 is included between the conductive layer 18 and the sidewall of the light emitting unit 1.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention; all other equivalent changes or modifications which are not departing from the spirit of the invention should be included in the following Within the scope of the patent application.

100. . . AC illuminator

400. . . AC illuminator

1. . . Light unit

10. . . Substrate

11. . . First illuminating subunit

11A. . . Epitaxial structure

11B. . . Epitaxial structure

11C. . . Tunneling layer

111. . . First doped layer

112. . . Luminous layer

113. . . Second doped layer

114. . . electrode

115. . . electrode

12. . . Second illuminating subunit

121. . . First doped layer

122. . . Luminous layer

123. . . Second doped layer

124. . . electrode

125. . . electrode

13. . . Tunneling layer

14. . . First conductive layer

15. . . First insulating layer

16. . . Second conductive layer

17. . . Second insulating layer

18. . . Conductive layer

19. . . Insulation

The first to first D diagrams show the alternating current illumination device of the first embodiment of the present invention.
The second figure illustrates another illumination unit of the first A diagram.
The third to third figures D show the implementation structure of the parallel electrical connection type of the first embodiment.
4A to 4D are views showing an alternating current light emitting device according to a second embodiment of the present invention.
The fifth figure shows a variation of the second embodiment of the present invention.

100. . . AC illuminator

1. . . Light unit

10. . . Substrate

11. . . First illuminating subunit

111. . . First doped layer

112. . . Luminous layer

113. . . Second doped layer

114. . . electrode

12. . . Second illuminating subunit

121. . . First doped layer

122. . . Luminous layer

123. . . Second doped layer

124. . . electrode

13. . . Tunneling layer

14. . . First conductive layer

15. . . First insulating layer

16. . . Second conductive layer

17. . . Second insulating layer

Claims (17)

An AC lighting device comprising:
a substrate;
A plurality of light emitting units are respectively disposed on the substrate, and each of the light emitting units comprises:
a first illuminating subunit;
a second illuminating subunit; and a tunneling junction layer;
The tunneling junction layer is located between the first illuminating sub-unit and the second illuminating sub-unit for electrically coupling the first illuminating sub-unit and the second illuminating sub-unit; and at least one conductive layer, The light-emitting units are connected to each other such that the first light-emitting sub-unit and the second light-emitting sub-unit of the same light-emitting unit are alternately driven to emit light according to the driving of the positive and negative half-cycle voltages of the alternating current power source. The illuminating device of claim 1, wherein the first illuminating subunit or the second illuminating subunit comprises at least one epitaxial structure, and each epitaxial structure comprises:
a first doped layer;
a light emitting layer; and a second doped layer;
Wherein the light emitting layer is located between the first doped layer and the second doped layer, and the first doped layer and the second doped layer are electrically opposite, whereby the tunneling junction layer is electrically The second doped layer of the first illuminating subunit and the first doped layer of the second illuminating subunit are coupled. The illuminating device of claim 2, wherein the adjacent two illuminating units have a parallel electrical connection mechanism for electrically connecting the intermediate nodes of the adjacent two illuminating units. The intermediate node refers to a region in which the first illuminating subunit and the second illuminating subunit are electrically coupled to each other. The illuminating device of claim 3, wherein the electrically coupled region of the intermediate node comprises a second doping layer of the first illuminating subunit or a first doping of the second illuminating subunit Floor. The AC lighting device of claim 3, wherein the parallel electrical connection mechanism comprises:
a first conductive layer electrically coupled to the corresponding doped layer of the adjacent two light emitting units; and a first insulating layer between the adjacent two light emitting units and located at the first conductive layer Below. The illuminating device of claim 5, wherein the corresponding doped layer comprises a first doped layer of the second illuminating subunit of the adjacent two illuminating units, or the second illuminating unit a second doped layer of an illuminating subunit. The illuminating device of claim 5, wherein the first insulating layer comprises a polymer, a ceramic material, or any combination thereof. The illuminating device of claim 2, wherein the adjacent two illuminating units have a crossover electrical connection mechanism for electrically connecting all external electrodes of the adjacent two illuminating units. Wherein the external electrode refers to an electrode that is in contact with the doped layer of the first and second illuminating sub-units that is farthest from the tunneling junction layer. The illuminating device of claim 8, wherein the external electrode comprises an electrode contacting the second doping layer of the second illuminating subunit or is in contact with the first doping layer of the first illuminating subunit Electrode. The AC lighting device of claim 8, wherein the interleaved electrical connection mechanism comprises:
a second conductive layer electrically connecting all the external electrodes of the adjacent two light emitting units; and a second insulating layer between the second conductive layer and the sidewall of the light emitting unit. The illuminating device of claim 10, wherein the external electrode comprises an electrode contacting the first doping layer of the first illuminating subunit of the adjacent illuminating unit, and the second illuminating subunit An electrode that is in contact with the doped layer. The illuminating device of claim 2, wherein the adjacent two illuminating units have a series/parallel electrical connection mechanism, comprising:
a conductive layer for connecting the external electrodes of the first and second illuminating sub-units of one of the illuminating units in series, and then connected in parallel with the internal electrodes of the adjacent one of the illuminating units at the intermediate node; and an insulating layer located at The conductive layer is between the sidewall of the light emitting unit. The illuminating device of claim 12, wherein the internal electrode of the intermediate node comprises an electrode contacting the first doped layer of the second illuminating subunit, or a second doping of the first illuminating subunit The electrode in contact with the hetero layer. The illuminating device of claim 1, wherein the tunneling junction layer comprises a group of four elements and a nitrogen element, and the atomic number of the group of elements and the nitrogen element accounts for the total atom of the tunneling interface layer. More than 50% of the percentage. The alternating current illuminating device of claim 1, wherein the tunneling junction layer comprises a defect-induced structure, the defect inducing structure providing a defect density greater than a growth plane of the tunnel junction layer More than five times the defect density. The AC illuminating device of claim 1, wherein the tunneling junction layer comprises a multilayer structure, and the thickness of the multilayer structure is less than or equal to 30 nm, the tunneling junction layer is undoped, or The doping concentration is less than the doping concentration of the adjacent first illuminating subunit and the second illuminating subunit. The alternating current illuminating device of claim 1, wherein the tunneling junction layer is doped with carbon, and the doping concentration of the carbon element is greater than 10 ¹⁷ atoms/cm 3 .