US20160118546A1 - Light emitting device with anti-total-internal-reflection capability - Google Patents
Light emitting device with anti-total-internal-reflection capability Download PDFInfo
- Publication number
- US20160118546A1 US20160118546A1 US14/807,328 US201514807328A US2016118546A1 US 20160118546 A1 US20160118546 A1 US 20160118546A1 US 201514807328 A US201514807328 A US 201514807328A US 2016118546 A1 US2016118546 A1 US 2016118546A1
- Authority
- US
- United States
- Prior art keywords
- light emitting
- emitting device
- transparent electrode
- metal oxide
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/44—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the coatings, e.g. passivation layer or anti-reflective coating
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/005—Processes
- H01L33/0062—Processes for devices with an active region comprising only III-V compounds
- H01L33/0075—Processes for devices with an active region comprising only III-V compounds comprising nitride compounds
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/26—Materials of the light emitting region
- H01L33/30—Materials of the light emitting region containing only elements of group III and group V of the periodic system
- H01L33/32—Materials of the light emitting region containing only elements of group III and group V of the periodic system containing nitrogen
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/36—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes
- H01L33/40—Materials therefor
- H01L33/42—Transparent materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2933/00—Details relating to devices covered by the group H01L33/00 but not provided for in its subgroups
- H01L2933/0008—Processes
- H01L2933/0016—Processes relating to electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2933/00—Details relating to devices covered by the group H01L33/00 but not provided for in its subgroups
- H01L2933/0008—Processes
- H01L2933/0025—Processes relating to coatings
Definitions
- This invention relates to a light emitting device with anti-total-internal-reflection (ATIF) capability, more particularly to a light emitting device including a total-internal-reflection suppression material dispersed in a transparent electrode layer.
- ATF anti-total-internal-reflection
- FIG. 1 illustrates a conventional light emitting device 1 that includes a sapphire substrate 11 , a light emitting layered structure 12 , a transparent electrode layer 13 , a first electrode contact 14 , a second electrode contact 15 , and a reflective layer 16 .
- the light emitting layered structure 12 includes a n-GaN layer 121 , an active layer 122 and a p-GaN layer 123 .
- the transparent electrode layer 13 may be made of indium tin oxide (ITO), and serves to permit uniform spread of an electric current in the light emitting layered structure 12 .
- ITO indium tin oxide
- the combination of the transparent electrode layer 13 and the p-GaN layer 123 results in generation of undesired total internal reflection at an interface therebetween, which results in a decrease in the light emitting efficiency.
- total internal reflection may also occur within the transparent electrode layer 13 , which further decreases the light emitting efficiency.
- U.S. Patent Application Publication No. 2014/0167085 discloses a light emitting device that includes a transparent substrate, a transparent electrode formed on the substrate, a light extraction layer formed on the transparent electrode, a light emitting layer formed on the light extraction layer and areas of the transparent electrode which are exposed from the light extraction layer, and a reflective electrode formed on the light emitting layer.
- the substrate may be formed of glass or plastic materials.
- the transparent electrode may be formed of a transparent metal oxide, such as indium tin oxide or indium zinc oxide.
- the light extraction layer serves to emit a light from the light emitting layer to the outside through the substrate, and may be made from a material having a similar refractive index to that of the substrate or a material having a refractive index greater than that of the light emitting layer .
- the light extraction layer may be formed of SiO 2 , TiO 2 , or a photoresist, and may include a plurality of scatters distributed in a transparent medium.
- the contact area between the light emitting layer and the transparent electrode is considerably reduced, which may result in a poor spreading of the electric current in the light emitting layer.
- the inclusion of the light extraction layer increases an overall layer thickness of the light emitting device.
- an object of the present invention is to provide a light emitting device that can overcome at least one of the aforesaid drawbacks associated with the prior art.
- a light emitting device with anti-total-internal-reflection capability includes: a light emitting layered structure; an electrode unit connected to the light emitting layered structure for providing electrical power to the light emitting layered structure, the electrode unit including a transparent electrode layer of a primary metal oxide which is stacked on the light emitting layered structure along a stacking direction; and a total-internal-reflection suppression material dispersed in the transparent electrode layer and containing a secondary metal oxide that is different from the primary metal oxide.
- the secondary metal oxide has a concentration gradient within the transparent electrode layer along the stacking direction.
- a method of making a light emitting device includes: preparing a light emitting layered structure; forming a particle layer, which contains metal nanoparticles of a first metal, on the light emitting layered structure; and simultaneously forming a transparent electrode layer of a primary metal oxide and at least partially oxidizing the first metal to form a secondary metal oxide, such that the secondary metal oxide is dispersed in the transparent electrode layer.
- FIG. 1 is a schematic view of a conventional light emitting device
- FIG. 2 is a schematic view of the embodiment of a light emitting device according to the present invention.
- FIG. 3 is a High Resolution Transmission Electron Microscope (HR-TEM) image of an assembly of a second type semiconductor layer and a transparent electrode layer of the embodiment;
- HR-TEM High Resolution Transmission Electron Microscope
- FIG. 4 is an amplified HR-TEM image of Region I shown in FIG. 3 ;
- FIG. 5 is an amplified HR-TEM image of Region II shown in FIG. 3 ;
- FIG. 6 is an amplified HR-TEM image of Region III shown in FIG. 3 ;
- FIGS. 7A to 7D are schematic views illustrating consecutive steps of a method of making the light emitting device according to the present invention.
- FIG. 8 is a plot of photoluminescent (PL) relative intensity versus wavelength for an example of the light emitting device of the present invention and a comparative example of a conventional light emitting device;
- PL photoluminescent
- FIG. 9 is a plot of light output power versus working current for the example of the light emitting device of the present invention and the comparative example of the conventional light emitting device; and FIG. 10 is a plot of electric current versus voltage for examples of the light emitting devices of the present invention and the comparative example of the conventional light emitting device.
- FIG. 2 in combination with FIGS. 3 to 6 , illustrates the embodiment of a light emitting device with anti-total-internal-reflection (ATIF) capability according to the present invention.
- ATF anti-total-internal-reflection
- the light emitting device includes: a substrate 2 ; a light emitting layered structure 3 ; an electrode unit 5 connected to the light emitting layered structure 3 for providing electrical power to the light emitting layered structure 3 , the electrode unit 5 including a transparent electrode layer 51 of a primary metal oxide 513 (see FIG. 4 ) which is stacked on the light emitting layered structure 3 along a stacking direction (X), the transparent electrode layer 51 having opposite first and second surfaces 511 , 512 ; and a total-internal-reflection (TIF) suppression material 4 dispersed in the transparent electrode layer 51 and containing a secondary metal oxide 41 that is different from the primary metal oxide 513 .
- TEZ total-internal-reflection
- the secondary metal oxide 41 has a concentration gradient within the transparent electrode layer 51 along the stacking direction (X).
- FIGS. 3 to 6 show that the concentration of the secondary metal oxide 41 may gradually increase inwardly from the first surface 511 (the concentration of the secondary metal oxide 41 is substantially zero at the first surface 511 ) and then gradually decrease toward the second surface 512 (the concentration of the secondary metal oxide 41 is substantially zero at the second surface 512 and the vicinity of the second surface 512 ).
- the total-internal-reflection suppression material 4 may provide function(s), such as light scattering, in the transparent electrode layer 51 , and is capable of suppressing total-internal-reflection within the transparent electrode layer 51 and at an interface between the transparent electrode layer 51 and the light emitting layered structure 3 .
- the light emitting layered structure 3 includes a buffer layer 31 , first and second type semiconductor layers 32 , 35 , an active layer 33 disposed between the first and second type semiconductor layers 32 , 35 , and a current barrier layer 34 disposed between the active layer 33 and the second type semiconductor layer 35 .
- the transparent electrode layer 51 is formed on the second type semiconductor layer 35 .
- the substrate 2 may be made of sapphire.
- the first and second type semiconductor layers 32 , 35 may be made of n-type and p-type GaN, respectively.
- the active layer 33 may include a GaN-based multi-quantum well, such as InGaN/GaN.
- the current barrier 34 may be made of AlGaN.
- the electrode unit 5 further includes a first electrode contact 52 that is formed on the transparent electrode layer 51 , and a second electrode contact 53 that is formed on the first type semiconductor layer 32 .
- the primary metal oxide 513 may be selected from the group consisting of indium tin oxide, tin oxide, zinc oxide, indium oxide, indium zinc oxide, gallium oxide, indium gallium oxide, indium zinc gallium oxide, zinc germanium oxide, and combinations thereof.
- the secondary metal oxide 41 may contain an oxide of a first metal that is selected from the group consisting of silver, gold, aluminum, platinum, titanium, zirconium, palladium, and nickel.
- the total-internal-reflection suppression material 4 may further contain nano-structures 42 of the first metal and a bi-metal oxide 43 of the first metal and a second metal.
- the second metal may be selected from the group of indium, gallium, and germanium.
- the transparent electrode layer 51 has a layer thickness that is preferably greater than 50 nm and less than 250 nm.
- the first surface 511 is in contact with the second type semiconductor layer 35 of the light emitting layered structure 3 .
- the total-internal-reflection suppression material 4 may have a depth (d) (see FIG. 2 ) from the first surface 511 toward the second surface 512 that is less than the layer thickness of the transparent electrode layer 51 .
- the depth (d) of the total-internal-reflection suppression material is preferably greater than 20 nm and less than 200 nm.
- the light emitting device of the present invention may be made by a method which includes the steps of: preparing the light emitting layered structure 3 which is formed on the substrate 2 ; forming a coating layer 6 , which contains a solvent 62 and metal nanoparticles 61 of a first metal dispersed in the solvent 62 , on the light emitting layered structure 3 using spin coating techniques (see FIG. 7A ); drying the coating layer 6 to form a particle layer 60 of the metal nanoparticles 61 on the light emitting layered structure 3 (see FIG.
- the first metal is silver
- the nano-structures thus formed include Ag 2 O phase (serving as the secondary metal oxide), AgInO 2 phase (serving as the bi-metal oxide), and Ag phase (unreacted first metal).
- the solvent 62 used in the coating layer 6 may be isopropanone.
- the concentration of the metal nanoparticles 61 in the coating layer 6 may range from 5 ppm to 50 ppm. The suppression of the total internal reflection is poor when the concentration of the metal nanoparticles 61 is less than 5 ppm, while the conductivity and the transparency of the transparent electrode layer 51 are considerably reduced when the concentration of the metal nanoparticles 61 is greater than 50 ppm.
- the concentration of the metal nanoparticles 61 in the coating layer 6 ranges from 5 ppm to 10 ppm.
- the metal nanoparticles 61 may have an average diameter greater than 20 nm and less than 100 nm.
- FIG. 8 is a plot of photoluminescence (PL) relative intensity versus wavelength for an example of the light emitting device of the present invention (with the total-internal-reflection suppression material 4 in the transparent electrode layer 51 ) and a comparative example of a conventional light emitting device (which is similar to the example of the light emitting device of the present invention but without the total-internal-reflection suppression material 4 in the transparent electrode layer 51 ).
- the results show that the example of the light emitting device of the present invention has a PL relative intensity higher than that of the comparative example of the conventional light emitting device over a wavelength from about 400 nm to about 500 nm.
- the concentration of the metal nanoparticles 61 in the coating layer 6 used in the method of making the aforesaid example of the light emitting device is about 10 ppm.
- FIG. 9 is a plot of light output power versus working current for the aforesaid example of the light emitting device of the present invention and the comparative example of the conventional light emitting device. The results show that the example of the light emitting device of the present invention has a light output power much higher than that of the comparative example of the conventional light emitting device over a working current from about 20 mA to about 450 mA.
- the light output power is increased by about 36% (from about 110 mW to 150 mW) for the aforesaid example of the light emitting device as compared to the comparative example when the working current is operated at about 400 mA, and is increased by about 44% (from about 90 mW to 130 mW) as compared to the comparative example when the working current is operated at about 300 mA.
- FIG. 10 is a plot of electric current versus voltage for examples of the light emitting devices of the present invention and the comparative example of the conventional light emitting device.
- the examples of the light emitting devices differ from one another in the concentration of the total-internal-reflection suppression material 4 in the transparent electrode layer 51 , which depends on the concentration of the metal nanoparticles 61 in the coating layer 6 employed in the method of the present invention.
- the concentrations of the metal nanoparticles 61 in the coating layer 6 for forming the examples of the light emitting devices are respectively 1 ppm, 5 ppm, 10 ppm, and 20 ppm.
- the results show that the comparative example of the conventional light emitting device has a higher electric current under a fixed voltage than that of each of the examples of the light emitting device of the present invention, which indicates that the inclusion of the total-internal-reflection suppression material 4 in the transparent electrode layer 51 increases the resistance or decreases the conductivity of the light emitting device.
- the results show that although having a lower conductivity, the light emitting devices (particularly those from examples with the concentration of the metal nanoparticles 61 in the coating layer 6 not greater than 10 ppm) can still achieve a satisfactory and competitive conductivity under a fixed voltage as compared to the conventional light emitting device.
- the aforesaid drawback with respect to the generation of the total-internal-reflection in the light emitting device may be alleviated.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Led Devices (AREA)
- Laminated Bodies (AREA)
Abstract
A light emitting device includes: a light emitting layered structure; an electrode unit connected to the light emitting layered structure and including a transparent electrode layer of a primary metal oxide which is stacked on the light emitting layered structure along a stacking direction; and a total-internal-reflection suppression material dispersed in the transparent electrode layer and containing a secondary metal oxide that is different from the primary metal oxide. The secondary metal oxide has a concentration gradient within the transparent electrode layer along the stacking direction. The light output power of the light emitting device may be increased by about 44% as compared to a conventional light emitting device.
Description
- This is a divisional application of U.S. patent application Ser. No. 14/602236, filed on Jan. 21, 2015, which claims the priority of Taiwanese Patent Application No. 103136799, filed on Oct. 24, 2014. This application claims the benefits and priority of all these prior applications and incorporates by reference the contents of these prior applications in their entirety.
- This invention relates to a light emitting device with anti-total-internal-reflection (ATIF) capability, more particularly to a light emitting device including a total-internal-reflection suppression material dispersed in a transparent electrode layer.
-
FIG. 1 illustrates a conventional light emitting device 1 that includes asapphire substrate 11, a light emitting layeredstructure 12, atransparent electrode layer 13, afirst electrode contact 14, asecond electrode contact 15, and areflective layer 16. The light emittinglayered structure 12 includes a n-GaN layer 121, anactive layer 122 and a p-GaN layer 123. Thetransparent electrode layer 13 may be made of indium tin oxide (ITO), and serves to permit uniform spread of an electric current in the light emittinglayered structure 12. However, the combination of thetransparent electrode layer 13 and the p-GaN layer 123 results in generation of undesired total internal reflection at an interface therebetween, which results in a decrease in the light emitting efficiency. - In addition, total internal reflection may also occur within the
transparent electrode layer 13, which further decreases the light emitting efficiency. - U.S. Patent Application Publication No. 2014/0167085 discloses a light emitting device that includes a transparent substrate, a transparent electrode formed on the substrate, a light extraction layer formed on the transparent electrode, a light emitting layer formed on the light extraction layer and areas of the transparent electrode which are exposed from the light extraction layer, and a reflective electrode formed on the light emitting layer. The substrate may be formed of glass or plastic materials. The transparent electrode may be formed of a transparent metal oxide, such as indium tin oxide or indium zinc oxide. The light extraction layer serves to emit a light from the light emitting layer to the outside through the substrate, and may be made from a material having a similar refractive index to that of the substrate or a material having a refractive index greater than that of the light emitting layer . For example, the light extraction layer may be formed of SiO2, TiO2, or a photoresist, and may include a plurality of scatters distributed in a transparent medium.
- Since a significant portion of the light emitting layer is covered by the light extraction layer, the contact area between the light emitting layer and the transparent electrode is considerably reduced, which may result in a poor spreading of the electric current in the light emitting layer. In addition, the inclusion of the light extraction layer increases an overall layer thickness of the light emitting device.
- Therefore, an object of the present invention is to provide a light emitting device that can overcome at least one of the aforesaid drawbacks associated with the prior art.
- According to one aspect of this invention, there is provided a light emitting device with anti-total-internal-reflection capability. The light emitting device includes: a light emitting layered structure; an electrode unit connected to the light emitting layered structure for providing electrical power to the light emitting layered structure, the electrode unit including a transparent electrode layer of a primary metal oxide which is stacked on the light emitting layered structure along a stacking direction; and a total-internal-reflection suppression material dispersed in the transparent electrode layer and containing a secondary metal oxide that is different from the primary metal oxide. The secondary metal oxide has a concentration gradient within the transparent electrode layer along the stacking direction.
- According to another aspect of this invention, there is provided a method of making a light emitting device. The method includes: preparing a light emitting layered structure; forming a particle layer, which contains metal nanoparticles of a first metal, on the light emitting layered structure; and simultaneously forming a transparent electrode layer of a primary metal oxide and at least partially oxidizing the first metal to form a secondary metal oxide, such that the secondary metal oxide is dispersed in the transparent electrode layer.
- In drawings which illustrate an embodiment of the invention,
-
FIG. 1 is a schematic view of a conventional light emitting device; -
FIG. 2 is a schematic view of the embodiment of a light emitting device according to the present invention; -
FIG. 3 is a High Resolution Transmission Electron Microscope (HR-TEM) image of an assembly of a second type semiconductor layer and a transparent electrode layer of the embodiment; -
FIG. 4 is an amplified HR-TEM image of Region I shown inFIG. 3 ; -
FIG. 5 is an amplified HR-TEM image of Region II shown inFIG. 3 ; -
FIG. 6 is an amplified HR-TEM image of Region III shown inFIG. 3 ; -
FIGS. 7A to 7D are schematic views illustrating consecutive steps of a method of making the light emitting device according to the present invention; -
FIG. 8 is a plot of photoluminescent (PL) relative intensity versus wavelength for an example of the light emitting device of the present invention and a comparative example of a conventional light emitting device; -
FIG. 9 is a plot of light output power versus working current for the example of the light emitting device of the present invention and the comparative example of the conventional light emitting device; andFIG. 10 is a plot of electric current versus voltage for examples of the light emitting devices of the present invention and the comparative example of the conventional light emitting device. -
FIG. 2 , in combination withFIGS. 3 to 6 , illustrates the embodiment of a light emitting device with anti-total-internal-reflection (ATIF) capability according to the present invention. - The light emitting device includes: a
substrate 2; a light emittinglayered structure 3; anelectrode unit 5 connected to the light emittinglayered structure 3 for providing electrical power to the light emittinglayered structure 3, theelectrode unit 5 including atransparent electrode layer 51 of a primary metal oxide 513 (seeFIG. 4 ) which is stacked on the light emittinglayered structure 3 along a stacking direction (X), thetransparent electrode layer 51 having opposite first andsecond surfaces suppression material 4 dispersed in thetransparent electrode layer 51 and containing asecondary metal oxide 41 that is different from theprimary metal oxide 513. Thesecondary metal oxide 41 has a concentration gradient within thetransparent electrode layer 51 along the stacking direction (X).FIGS. 3 to 6 show that the concentration of thesecondary metal oxide 41 may gradually increase inwardly from the first surface 511 (the concentration of thesecondary metal oxide 41 is substantially zero at the first surface 511) and then gradually decrease toward the second surface 512 (the concentration of thesecondary metal oxide 41 is substantially zero at thesecond surface 512 and the vicinity of the second surface 512). The total-internal-reflection suppression material 4 may provide function(s), such as light scattering, in thetransparent electrode layer 51, and is capable of suppressing total-internal-reflection within thetransparent electrode layer 51 and at an interface between thetransparent electrode layer 51 and the light emittinglayered structure 3. - In this embodiment, the light emitting
layered structure 3 includes abuffer layer 31, first and second type semiconductor layers 32, 35, anactive layer 33 disposed between the first and second type semiconductor layers 32, 35, and acurrent barrier layer 34 disposed between theactive layer 33 and the secondtype semiconductor layer 35. Thetransparent electrode layer 51 is formed on the secondtype semiconductor layer 35. - The
substrate 2 may be made of sapphire. The first and second type semiconductor layers 32, 35 may be made of n-type and p-type GaN, respectively. Theactive layer 33 may include a GaN-based multi-quantum well, such as InGaN/GaN. Thecurrent barrier 34 may be made of AlGaN. - The
electrode unit 5 further includes afirst electrode contact 52 that is formed on thetransparent electrode layer 51, and asecond electrode contact 53 that is formed on the firsttype semiconductor layer 32. - The
primary metal oxide 513 may be selected from the group consisting of indium tin oxide, tin oxide, zinc oxide, indium oxide, indium zinc oxide, gallium oxide, indium gallium oxide, indium zinc gallium oxide, zinc germanium oxide, and combinations thereof. - The
secondary metal oxide 41 may contain an oxide of a first metal that is selected from the group consisting of silver, gold, aluminum, platinum, titanium, zirconium, palladium, and nickel. - The total-internal-
reflection suppression material 4 may further contain nano-structures 42 of the first metal and abi-metal oxide 43 of the first metal and a second metal. The second metal may be selected from the group of indium, gallium, and germanium. - The
transparent electrode layer 51 has a layer thickness that is preferably greater than 50 nm and less than 250 nm. Thefirst surface 511 is in contact with the secondtype semiconductor layer 35 of the light emittinglayered structure 3. The total-internal-reflection suppression material 4 may have a depth (d) (seeFIG. 2 ) from thefirst surface 511 toward thesecond surface 512 that is less than the layer thickness of thetransparent electrode layer 51. The depth (d) of the total-internal-reflection suppression material is preferably greater than 20 nm and less than 200 nm. The light emitting device of the present invention may be made by a method which includes the steps of: preparing the light emittinglayered structure 3 which is formed on thesubstrate 2; forming a coating layer 6, which contains a solvent 62 andmetal nanoparticles 61 of a first metal dispersed in the solvent 62, on the light emittinglayered structure 3 using spin coating techniques (seeFIG. 7A ); drying the coating layer 6 to form aparticle layer 60 of themetal nanoparticles 61 on the light emitting layered structure 3 (seeFIG. 7B ); subjecting an assembly of theparticle layer 60 and the light emittinglayered structure 3 to an e-beam evaporation deposition process under the presence of oxygen to simultaneously form atransparent electrode layer 51 of aprimary metal oxide 513 on thesubstrate 2 and at least partially oxidize the first metal of themetal nanoparticles 61 to form nano-structures, such that the nano-structures thus formed are dispersed in the transparent electrode layer 51 (seeFIG. 7C ); subjecting thetransparent electrode layer 51 to an annealing process; and forming first andsecond electrode contacts transparent electrode layer 51 and the firsttype semiconductor layer 32, respectively (seeFIG. 7D ). In one embodiment, the first metal is silver, and the nano-structures thus formed include Ag2O phase (serving as the secondary metal oxide), AgInO2 phase (serving as the bi-metal oxide), and Ag phase (unreacted first metal). - The solvent 62 used in the coating layer 6 may be isopropanone. The concentration of the
metal nanoparticles 61 in the coating layer 6 may range from 5 ppm to 50 ppm. The suppression of the total internal reflection is poor when the concentration of themetal nanoparticles 61 is less than 5 ppm, while the conductivity and the transparency of thetransparent electrode layer 51 are considerably reduced when the concentration of themetal nanoparticles 61 is greater than 50 ppm. Preferably, the concentration of themetal nanoparticles 61 in the coating layer 6 ranges from 5 ppm to 10 ppm. In addition, themetal nanoparticles 61 may have an average diameter greater than 20 nm and less than 100 nm. -
FIG. 8 is a plot of photoluminescence (PL) relative intensity versus wavelength for an example of the light emitting device of the present invention (with the total-internal-reflection suppression material 4 in the transparent electrode layer 51) and a comparative example of a conventional light emitting device (which is similar to the example of the light emitting device of the present invention but without the total-internal-reflection suppression material 4 in the transparent electrode layer 51). The results show that the example of the light emitting device of the present invention has a PL relative intensity higher than that of the comparative example of the conventional light emitting device over a wavelength from about 400 nm to about 500 nm. Note that the concentration of themetal nanoparticles 61 in the coating layer 6 used in the method of making the aforesaid example of the light emitting device is about 10 ppm. -
FIG. 9 is a plot of light output power versus working current for the aforesaid example of the light emitting device of the present invention and the comparative example of the conventional light emitting device. The results show that the example of the light emitting device of the present invention has a light output power much higher than that of the comparative example of the conventional light emitting device over a working current from about 20 mA to about 450 mA. For instance, the light output power is increased by about 36% (from about 110 mW to 150 mW) for the aforesaid example of the light emitting device as compared to the comparative example when the working current is operated at about 400 mA, and is increased by about 44% (from about 90 mW to 130 mW) as compared to the comparative example when the working current is operated at about 300 mA. -
FIG. 10 is a plot of electric current versus voltage for examples of the light emitting devices of the present invention and the comparative example of the conventional light emitting device. The examples of the light emitting devices differ from one another in the concentration of the total-internal-reflection suppression material 4 in thetransparent electrode layer 51, which depends on the concentration of themetal nanoparticles 61 in the coating layer 6 employed in the method of the present invention. - The concentrations of the
metal nanoparticles 61 in the coating layer 6 for forming the examples of the light emitting devices are respectively 1 ppm, 5 ppm, 10 ppm, and 20 ppm. The results show that the comparative example of the conventional light emitting device has a higher electric current under a fixed voltage than that of each of the examples of the light emitting device of the present invention, which indicates that the inclusion of the total-internal-reflection suppression material 4 in thetransparent electrode layer 51 increases the resistance or decreases the conductivity of the light emitting device. The results also show that although having a lower conductivity, the light emitting devices (particularly those from examples with the concentration of themetal nanoparticles 61 in the coating layer 6 not greater than 10 ppm) can still achieve a satisfactory and competitive conductivity under a fixed voltage as compared to the conventional light emitting device. - With the inclusion of the total-internal-
reflection suppression material 4 in thetransparent electrode layer 51 of the light emitting device of the present invention, the aforesaid drawback with respect to the generation of the total-internal-reflection in the light emitting device may be alleviated. - While the present invention has been described in connection with what is considered the most practical embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation and equivalent arrangements.
Claims (6)
1. A method of making a light emitting device comprising:
preparing a light emitting layered structure;
forming a particle layer, which contains metal nanoparticles of a first metal, on the light emitting layered structure; and
simultaneously forming a transparent electrode layer of a primary metal oxide and at least partially oxidizing the first metal to form a secondary metal oxide, such that the secondary metal oxide is dispersed in the transparent electrode layer,
wherein formation of the particle layer is conducted by forming a coating layer containing a solvent and the metal nanoparticles on a surface of the light emitting layered structure, followed by drying,
wherein the concentration of the metal nanoparticles in the coating layer ranges from 5 ppm to 50 ppm.
2. The method of claim 1 , wherein formation of the primary metal oxide and the secondary metal oxide is conducted under the presence of oxygen.
3. The method of claim 1 , wherein the first metal is selected from the group consisting of silver, gold, aluminum, platinum, titanium, zirconium, palladium, and nickel.
4. (canceled)
5. The method of claim 4 , wherein the metal nanoparticles have an average diameter greater than 20 nm and less than 100 nm.
6. (canceled)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/807,328 US20160118546A1 (en) | 2014-10-24 | 2015-07-23 | Light emitting device with anti-total-internal-reflection capability |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
TW103136799A TWI581452B (en) | 2014-10-24 | 2014-10-24 | High light extraction rate of light-emitting diodes, conductive films, and conductive films |
TW103136799 | 2014-10-24 | ||
US14/602,236 US9331250B1 (en) | 2014-10-24 | 2015-01-21 | Light emitting device with anti-total-internal-reflection capability |
US14/807,328 US20160118546A1 (en) | 2014-10-24 | 2015-07-23 | Light emitting device with anti-total-internal-reflection capability |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/602,236 Division US9331250B1 (en) | 2014-10-24 | 2015-01-21 | Light emitting device with anti-total-internal-reflection capability |
Publications (1)
Publication Number | Publication Date |
---|---|
US20160118546A1 true US20160118546A1 (en) | 2016-04-28 |
Family
ID=55792655
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/602,236 Active US9331250B1 (en) | 2014-10-24 | 2015-01-21 | Light emitting device with anti-total-internal-reflection capability |
US14/807,328 Abandoned US20160118546A1 (en) | 2014-10-24 | 2015-07-23 | Light emitting device with anti-total-internal-reflection capability |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/602,236 Active US9331250B1 (en) | 2014-10-24 | 2015-01-21 | Light emitting device with anti-total-internal-reflection capability |
Country Status (3)
Country | Link |
---|---|
US (2) | US9331250B1 (en) |
CN (1) | CN105845802B (en) |
TW (1) | TWI581452B (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2019071160A1 (en) * | 2017-10-06 | 2019-04-11 | Glo Ab | Light emitting diode containing oxidized metal contacts |
US10276752B2 (en) * | 2015-07-16 | 2019-04-30 | Osram Opto Semiconductors Gmbh | Optoelectronic semiconductor component and method of producing an optoelectronic semiconductor component |
US11362238B2 (en) | 2017-10-06 | 2022-06-14 | Nanosys, Inc. | Light emitting diode containing oxidized metal contacts |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9391232B1 (en) * | 2014-12-19 | 2016-07-12 | Intermolecular, Inc. | Variable composition transparent conductive oxide layer and methods of forming thereof |
Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7507447B2 (en) | 2002-02-26 | 2009-03-24 | Fujifilm Corporation | Transparent conductive film, method for producing same and method for forming pattern |
KR100580634B1 (en) * | 2003-12-24 | 2006-05-16 | 삼성전자주식회사 | light emitting device and method of manufacturing thereof |
JP4254681B2 (en) | 2004-09-30 | 2009-04-15 | 豊田合成株式会社 | Electrode formation method |
TW200742117A (en) * | 2006-04-27 | 2007-11-01 | Genesis Photonics Inc | Light-emitting diode having forward light-guide structure and method manufacturing the same |
KR100993074B1 (en) * | 2009-12-29 | 2010-11-08 | 엘지이노텍 주식회사 | Light emitting device, method for fabricating the same and light emitting device package |
KR101134191B1 (en) * | 2010-04-26 | 2012-04-09 | 전북대학교산학협력단 | Surface Plasmon Resonance-based Light Emitting Diode Using Core-Shell Nanoparticles |
US8309185B2 (en) * | 2010-05-04 | 2012-11-13 | National Tsing Hua University | Nanoparticle film and forming method and application thereof |
JP5852022B2 (en) * | 2011-02-09 | 2016-02-03 | 新日鉄住金化学株式会社 | Metal fine particle dispersed composite, method for producing the same, and localized surface plasmon resonance generating substrate |
TWI462334B (en) * | 2011-08-01 | 2014-11-21 | Lextar Electronics Corp | Light emitting diode structure and manufacture method thereof |
KR101283538B1 (en) * | 2011-11-07 | 2013-07-15 | 삼성전자주식회사 | Enhanced luminescence light emitting device using surface plasmon resonance |
KR101559194B1 (en) * | 2012-09-14 | 2015-10-12 | 한양대학교 산학협력단 | Surface plasmon resonance optical materials using conductive oxide nanoparticles, method for fabricating the same and optical devices comprising the same |
CN103840056A (en) * | 2012-11-22 | 2014-06-04 | 海洋王照明科技股份有限公司 | LED light source enhanced by fluorescence and surface plasmas |
KR101715843B1 (en) | 2012-12-14 | 2017-03-14 | 삼성전자주식회사 | Light emitting device having improved light extraction efficiency |
TWM474261U (en) * | 2013-06-07 | 2014-03-11 | Cheng-Sheng Zong | Composite three-dimensional surface plasma structure |
TWI472059B (en) * | 2013-10-09 | 2015-02-01 | Cheng Sheng Tsung | A method of forming a surface plasma using a microstructure |
-
2014
- 2014-10-24 TW TW103136799A patent/TWI581452B/en active
-
2015
- 2015-01-14 CN CN201510017716.7A patent/CN105845802B/en active Active
- 2015-01-21 US US14/602,236 patent/US9331250B1/en active Active
- 2015-07-23 US US14/807,328 patent/US20160118546A1/en not_active Abandoned
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10276752B2 (en) * | 2015-07-16 | 2019-04-30 | Osram Opto Semiconductors Gmbh | Optoelectronic semiconductor component and method of producing an optoelectronic semiconductor component |
WO2019071160A1 (en) * | 2017-10-06 | 2019-04-11 | Glo Ab | Light emitting diode containing oxidized metal contacts |
US10804436B2 (en) | 2017-10-06 | 2020-10-13 | Glo Ab | Light emitting diode containing oxidized metal contacts |
US11362238B2 (en) | 2017-10-06 | 2022-06-14 | Nanosys, Inc. | Light emitting diode containing oxidized metal contacts |
US11710805B2 (en) | 2017-10-06 | 2023-07-25 | Nanosys, Inc. | Light emitting diode containing oxidized metal contacts |
Also Published As
Publication number | Publication date |
---|---|
TW201616670A (en) | 2016-05-01 |
TWI581452B (en) | 2017-05-01 |
US9331250B1 (en) | 2016-05-03 |
CN105845802B (en) | 2018-08-03 |
US20160118545A1 (en) | 2016-04-28 |
CN105845802A (en) | 2016-08-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9859468B2 (en) | Small-sized light-emitting diode chiplets and method of fabrication thereof | |
US20070029561A1 (en) | Omni-directional reflector and light emitting diode adopting the same | |
US9214595B2 (en) | Semiconductor light emitting device | |
US20120009705A1 (en) | Techniques of Forming Ohmic Contacts on GaN Light Emitting Diodes | |
US9331250B1 (en) | Light emitting device with anti-total-internal-reflection capability | |
JP2011187658A (en) | Semiconductor light-emitting element | |
US11005007B2 (en) | Light-emitting device and manufacturing method thereof | |
JP5165254B2 (en) | Flip chip type light emitting device | |
TW201637240A (en) | Semiconductor light emitting element and method of manufacturing the same | |
US10475961B2 (en) | Optoelectronic semiconductor chip | |
JP2010272592A (en) | Semiconductor light emitting element | |
Lee et al. | Impact of tin-oxide nanoparticles on improving the carrier transport in the Ag/p-GaN interface of InGaN/GaN micro-light-emitting diodes by originating inhomogeneous Schottky barrier height | |
JP2011505073A (en) | Optoelectronic semiconductor body and method of manufacturing optoelectronic semiconductor body | |
JP5378131B2 (en) | Nitride semiconductor light emitting diode device | |
CN108565319A (en) | Nitride semiconductor structure and semiconductor light-emitting elements | |
TWI699906B (en) | Semiconductor light-emitting device | |
KR101805301B1 (en) | Ultraviolet Light-Emitting Diode with p-type ohmic contact electrode pattern to enhance the light extraction | |
Lin et al. | GaN-Based LEDs With Omnidirectional Metal Underneath an Insulating ${\rm SiO} _ {2} $ Layer | |
KR101280501B1 (en) | Light emitting diodes using a transparent electrode | |
TW201543710A (en) | Semiconductor light emitting element | |
TWI258228B (en) | Light emitting semiconductor device | |
JP5158813B2 (en) | Nitride-based semiconductor light-emitting device and manufacturing method thereof | |
Noh et al. | High Efficiency Flip Chip-Based UV Emitter with Indium Tin Oxide Nano Grains/Al Reflector and Periodic Microhole Arrays | |
KR101675020B1 (en) | Light emitting diode and Method for manufacturing for the same | |
TWI535062B (en) | LED components |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: NATIONAL CHUNG HSING UNIVERSITY, TAIWAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:WUU, DONG-SING;CHUANG, SHIH-HAO;HORNG, RAY-HUA;REEL/FRAME:036166/0004 Effective date: 20150112 |
|
STCB | Information on status: application discontinuation |
Free format text: EXPRESSLY ABANDONED -- DURING EXAMINATION |