TW202207491A - Light-emitting device and display device having the same - Google Patents

Abstract

A light-emitting device includes: a semiconductor stack; and a filter on the semiconductor stack, wherein the filter includes a first surface facing the semiconductor stack and a second surface opposite to the first surface; wherein: the light-emitting device emits a light; the light includes a first light within a first direction, and the first light has a first full width at half maximum (FWHM); and a second light within a second direction, and the second light has a second FWHM; the angle between the first direction and a normal vector of the second surface is between 45-90 degrees and the angle between the second direction and the a normal vector of the second surface is between 0-30 degrees; and the second FWHM is smaller than the first FWHM.

Description

Light-emitting element and display device

The present invention relates to a light-emitting element and a display device, and more particularly, to a light-emitting element having a filter layer and a display device having the light-emitting element.

Light-emitting diodes (LEDs) in solid-state light-emitting devices have the advantages of low power consumption, high brightness, high color rendering, and small size, and have been widely used in various lighting and display devices. For example, as a pixel of a display device, a light-emitting element can replace a traditional liquid crystal display device and achieve a higher-quality display effect. When a light-emitting element is applied to a display device, how to maintain the optoelectronic properties of the light-emitting element and improve the display effect of the display device is one of the research and development goals of those skilled in the art.

A light-emitting element, comprising: a semiconductor stack; and a filter layer, located on the semiconductor stack, comprising a first surface facing the semiconductor stack and a second surface opposite to the first surface; wherein: the light-emitting element emits a light; the light includes a first directional light, which has a first half-width; and a second directional light, which has a second half-width; the first direction and the normal direction of the second surface The included angle is 45-90 degrees, the included angle between the second direction and the normal direction of the second surface is 0-30 degrees; and the second half-height width is smaller than the first half-height width.

A light-emitting element, comprising: a semiconductor stack, emitting a first light; and a filter layer, located on the semiconductor stack, comprising a first surface facing the semiconductor stack and a second surface opposite to the first surface; Wherein: the first ray obtains a second ray through the filter layer; the first ray has a first half-height width, the second ray has a second half-height-width; and the second half-height-width is smaller than the first half-height-width, And/or the second light has a half height and width less than or equal to 25 nm.

A light-emitting element, comprising: a semiconductor stack, emitting a first light; and a filter layer, located on the semiconductor stack, comprising a first surface facing the semiconductor stack and a second surface opposite to the first surface; Wherein: the filter layer includes a first dielectric material layer and a second dielectric material layer stacked alternately; the first light obtains a second light through the filter layer; and the light-emitting element has a divergence angle ranging from 50 degrees to 110 degrees.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings, such that Those skilled in the art of the present invention can fully understand the spirit of the present invention. The present invention is not limited to the following example, but may be implemented in other forms. In this manual, there are some identical symbols No., which represents the components with the same or similar structure, function and principle, and is the industry's Those with ordinary knowledge can make inferences based on the teachings of this manual. Test the simplicity of the manual Quantities, elements with the same symbols will not be repeated.

FIG. 1 shows a cross-sectional view of a light-emitting device 1 according to a first embodiment of the present application. As shown in FIG. 1 , the light-emitting element 1 includes a substrate 10, and a semiconductor stack 12 is located on the first surface 10a of the substrate, wherein the semiconductor stack 12 includes a first semiconductor layer 121 and an active layer 123 on the first surface 10a of the substrate in sequence. And a second semiconductor layer 122 , the first semiconductor layer 121 has a first surface 121 a not covered by the active layer 123 and the second semiconductor layer 122 . The transparent conductive layer 18 is located on the second semiconductor layer 122 , the first electrode 20 is located on the first surface 121 a of the first semiconductor layer, and the second electrode 30 is located on the transparent conductive layer 18 . The filter layer 50 is on the semiconductor stack 12 . A reflection structure 16 is provided on the second surface 10b of the substrate 10 opposite to the first surface 10a.

The substrate 10 may be a growth substrate, including a gallium arsenide (GaAs) substrate for growing gallium indium phosphide (AlGaInP), and a gallium phosphide (GaP) substrate, or for growing indium gallium nitride (InGaN) or nitrogen Aluminum gallium (AlGaN) sapphire (Al ₂ O ₃ ) substrates, gallium nitride (GaN) substrates, silicon carbide (SiC) substrates, and aluminum nitride (AlN) substrates. The substrate 10 may be a patterned substrate, that is, the substrate 10 has a patterned structure on its first surface 10a (not shown). In one embodiment, the light emitted from the semiconductor stack 12 may be refracted by the patterned structure of the substrate 10, thereby increasing the brightness of the light-emitting element. In addition, the patterned structure slows down or suppresses the dislocation caused by lattice mismatch between the substrate 10 and the semiconductor stack 12 , thereby improving the epitaxial quality of the semiconductor stack 12 .

In one embodiment of the present application, the method of forming the semiconductor stack 12 on the substrate 10 includes metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE) Or ion plating, such as sputtering or evaporation, etc.

The semiconductor stack 12 further includes a buffer structure (not shown) between the first surface 10 a of the substrate and the first semiconductor layer 121 . The buffer structure, the first semiconductor layer 121 , the active layer 123 and the second semiconductor layer 122 constitute the semiconductor stack 12 . The buffer structure can reduce the above-mentioned lattice mismatch and suppress dislocation, thereby improving epitaxial quality. The material of the buffer layer includes GaN, AlGaN or AlN. In one embodiment, the buffer structure includes multiple sub-layers (not shown). The sublayers include the same material or different materials. In one embodiment, the buffer structure includes two sub-layers, wherein the growth method of the first sub-layer is sputtering, and the growth method of the second sub-layer is MOCVD. In one embodiment, the buffer layer further includes a third sublayer. The growth mode of the third sublayer is MOCVD, and the growth temperature of the second sublayer is higher or lower than the growth temperature of the third sublayer. In one embodiment, the first, second and third sublayers comprise the same material, eg, AlN, or different materials, eg, AN, GaN, AlGaN. In an embodiment of the present application, the first semiconductor layer 121 and the second semiconductor layer 122, such as a cladding layer or a confinement layer, have different conductivity types, electrical properties, and polarities Or doping elements used to provide electrons or holes. For example, the first semiconductor layer 121 is an n-type semiconductor, and the second semiconductor layer 122 is a p-type semiconductor. The active layer 123 is formed between the first semiconductor layer 121 and the second semiconductor layer 122 . Electrons and holes are combined in the active layer 123 under the driving of current, converting electrical energy into light energy to emit light. The wavelength of the light emitted by the light emitting element 1 or the semiconductor stack 12 can be adjusted by changing the physical properties and chemical composition of one or more layers in the semiconductor stack 12 .

The material of the semiconductor stack 12 includes a III-V semiconductor material of AlxInyGa(1- _{xy )} N or _AlxInyGa (1- _{xy )} P, where 0≤x, y≤1; x+ _y ≤1. Depending on the material of the active layer, when the material of the semiconductor stack 12 is AlInGaP series, red light with a wavelength between 570 nm and 780 nm or yellow light with a wavelength between 550 nm and 570 nm can be emitted. When the material of the semiconductor stack 12 is InGaN series, blue light or deep blue light with wavelengths between 380 nm and 490 nm or green light with wavelengths between 490 nm and 550 nm can be emitted. The active layer 123 may be a single heterostructure (SH), a double heterostructure (DH), a double-side double heterostructure (DDH), a multi-quantum well (MQW) ). The material of the active layer 123 may be an i-type, p-type or n-type semiconductor.

The transparent conductive layer 18 is in electrical contact with the second semiconductor layer 122 for laterally dispersing current. In another embodiment, the transparent conductive layer 18 may include an opening (not shown) under the second electrode 30 to expose the second semiconductor layer 122 , and the second electrode 30 may contact the second semiconductor layer through the opening of the transparent conductive layer 18 122. The transparent conductive layer 18 can be a metal or a transparent conductive material, wherein the metal can be selected from a thin metal layer with light transmittance, and the transparent conductive material is transparent to the light emitted by the active layer 123, including graphene, indium tin oxide ( ITO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), zinc oxide (ZnO) or indium zinc oxide (IZO).

The first electrode 20 is located on the first surface 121 a of the first semiconductor layer and is electrically connected to the first semiconductor layer 121 . The second electrode 30 is electrically connected to the second semiconductor layer 121 . The first electrode 20 and the second electrode 30 respectively include a pad electrode. In FIG. 1 , only the pad electrodes of the first electrode 20 and the second electrode 30 are exemplarily shown. In another embodiment, the first electrode 20 and/or the second electrode 30 further include finger electrodes (not shown) extending from the pad electrodes. The pad electrodes of the first electrode 20 and the second electrode 30 are used for wire bonding or welding to electrically connect the light-emitting element 1 with an external power source or an external electronic element. The materials of the first electrode 20 and the second electrode 30 include metals, such as chromium (Cr), titanium (Ti), gold (Au), aluminum (Al), copper (Cu), silver (Ag), tin (Sn), Metals such as nickel (Ni), rhodium (Rh) or platinum (Pt), or alloys or laminates of the above materials.

In one embodiment, the light-emitting element 1 may further include a current blocking layer (not shown) between the transparent conductive layer 18 and the second semiconductor layer 122 , and/or between the first electrode 20 and the first semiconductor layer 121 . between.

The filter layer 50 includes openings 501 and 502. In this embodiment, as shown in FIG. 1, the filter layer 50 covers the semiconductor stack 12, the transparent conductive layer 18 and part of the first electrode 20 and the second electrode 30. The first electrodes 20 and the second electrodes 30 are exposed through the openings 501 and 502 respectively, and more specifically, the pad electrodes of the first electrodes 20 and the second electrodes 30 are exposed. In another embodiment (not shown), the filter layer 50 does not cover the first electrode 20 and the second electrode 30 . In another embodiment (not shown), the filter layer 50 covers the semiconductor stack 12 and the transparent conductive layer 18 and extends to a part of the first electrode 20 and the second electrode 30 under the first electrode 20 and the second electrode. 30 is electrically connected to the semiconductor stack 12 through openings 501 and 502 thereunder, respectively.

The filter layer 50 is formed by alternately stacking a pair or a plurality of pairs of material layers with different refractive indices, and provides a filtering function for light in a specific wavelength range. When the light-emitting element 1 emits light of a single color, the light of a specific wavelength range can be filtered by the filter layer 50 to purify the light of a single color emitted by the light-emitting element 1 . In addition, in one embodiment, the filter layer 50 can also be used as a protection structure at the same time, and has the function of protecting the light-emitting element, such as blocking external moisture from entering the light-emitting element. In one embodiment, through the selection of different refractive index dielectric materials and their thickness design, an interference phenomenon is formed, so that the light emitted by the light-emitting element is selectively transmitted or reflected through the filter layer 50, and only has a specific wavelength. A range of light can pass through the filter layer 50 to achieve a filter effect. The filter layer 50 may have a band-pass filter function, a low-pass filter function or a high-pass filter function.

FIG. 2A shows an enlarged partial cross-sectional view of the filter layer 50. In this embodiment, as shown in FIG. 2A, the filter layer 50 includes a first set of material stacks, consisting of a first sub-layer 50a and a second sub-layer 50b stack. The first set of material stacks includes, for example, dielectric materials, and a first sub-layer 50a and a second sub-layer 50b form a pair of dielectric materials. The first sub-layer 50a has a higher refractive index than the second sub-layer 50b. Through the selection of different refractive index materials and their thickness design, light in a specific wavelength range can be filtered. In one embodiment, the first sub-layer 50a has a smaller thickness than the second sub-layer 50b. Dielectric materials include, for example, silicon oxide, silicon nitride, silicon oxynitride, niobium oxide, hafnium oxide, titanium oxide, magnesium fluoride, aluminum oxide, and the like. In one embodiment, the filter layer 50 is, for example, a distributed Bragg reflector (DBR).

In one embodiment, the filter layer 50 may further include layers other than the first sub-layer 50a and the second sub-layer 50b. For example, the filter layer 50 further includes a bottom layer (not shown) between the first sub-layer 50 a (and/or the second sub-layer 50 b ) and the semiconductor stack 12 . That is, the bottom layer is formed on the semiconductor stack 12 first, and then the first sub-layer 50a and the second sub-layer 50b are formed. In one embodiment, the bottom layer includes a dielectric material with a thickness greater than that of the first sub-layer 50a and the second sub-layer 50b. In one embodiment, the formation method of the bottom layer is different from that of the first sub-layer 50a and the second sub-layer 50b. For example, the formation method of the bottom layer is chemical vapor deposition (CVD). It is formed by plasma enhanced chemical vapor deposition (PECVD). The first sub-layer 50a and the second sub-layer 50b are formed by sputtering. In one embodiment, the bottom layer can provide a function of protecting the light-emitting element or protecting the semiconductor stack, such as blocking external moisture from entering the light-emitting element.

In another embodiment, as shown in FIG. 2B , the filter layer 50 includes a plurality of material stacks, the first material stack is composed of a stack of a first sublayer 50a and a second sublayer 50b, and the second material stack The stack consists of a stack of a third sub-layer 50c and a fourth sub-layer 50d. The second set of material stacks include, for example, dielectric materials, and a third sub-layer 50c and a fourth sub-layer 50d form a pair of dielectric materials. The third sub-layer 50c has a higher refractive index than the fourth sub-layer 50d. In one embodiment, the third sub-layer 50c has a smaller thickness than the fourth sub-layer 50d. The third sublayer 50c and the first sublayer 50a have different thicknesses, and the third sublayer 50c and the first sublayer 50a may be of the same material or different materials. The fourth sub-layer 50d and the second sub-layer 50b have different thicknesses, and the fourth sub-layer 50d and the second sub-layer 50b may be made of the same material or different materials.

In another embodiment, the filter layer 50 may further include an upper layer (not shown) on the first sub-layer 50 a (and/or the second sub-layer 50 b ), opposite to the other side of the second semiconductor layer 122 . That is, the first sub-layer 50a and the second sub-layer 50b are formed on the semiconductor stack 12 first, and then the upper layer is formed. The upper layer includes a dielectric material with a thickness greater than that of the first sub-layer 50a and the second sub-layer 50b. In one embodiment, the formation method of the upper layer is different from that of the first sub-layer 50a and the second sub-layer 50b. For example, the formation method of the upper layer is chemical vapor deposition (CVD), and more preferably, by plasma-assisted chemical vapor deposition. phase deposition (PECVD). The first sub-layer 50a and the second sub-layer 50b are formed by sputtering. In one embodiment, the upper layer can increase the strength of the entire filter layer 50 . For example, when the filter layer 50 is subjected to external force, the upper layer can prevent the filter layer 50 from being broken and damaged by the external force.

In another embodiment, the filter layer 50 includes a plurality of material stacks and a bottom layer and/or an upper layer.

In another embodiment, before the filter layer 50 is formed, a dense layer (not shown) is formed on the surface of the transparent conductive layer 18 and the semiconductor stack 20 by atomic deposition to directly cover the semiconductor stack 12 . The material of the dense layer includes silicon oxide, aluminum oxide, hafnium oxide, tantalum oxide, zirconium oxide, yttrium oxide, lanthanum oxide, tantalum oxide, silicon nitride, aluminum nitride or silicon oxynitride. In this embodiment, the interface between the dense layer and the semiconductor stack 12 includes metal elements and oxygen, wherein the metal elements include aluminum, hafnium, tantalum, zirconium, yttrium, lanthanum or tantalum. The dense layer comprises a thickness between 50 Å and 2000 Å, preferably between 100 Å and 1500 Å. In one embodiment, the dense layer can be formed on the semiconductor stack 12 by conformal covering, and can provide a better protection function for the semiconductor stack 12 by virtue of its film quality, such as preventing moisture from entering the semiconductor stack 12, and can protect the semiconductor stack 12. Adhesion between the filter layer 50 and the semiconductor stack 12 is aided.

In one embodiment, the filter layer 50 includes more than 4 pairs and less than 30 pairs of dielectric material pairs. When the dielectric material pairs are less than 4 pairs, the filtering effect is not good. When there are more than 30 pairs of dielectric materials, the fabrication cost will increase. Preferably, the filter layer 50 includes more than 8 pairs and less than 20 pairs of dielectric material pairs. Taking a filter layer 50 with a low-pass filter function as an example, the filter layer 50 has a transmittance of more than 95% for a light with a wavelength less than λ _on , and has a transmittance of less than 5% for a light with a wavelength greater than λ _off . penetration rate. For wavelengths between _λon and _λoff , depending on the number of pairs of dielectric material of the filter layer 50, the transmittance has a dramatic change. In one embodiment, when the filter layer 50 includes more than 8 pairs of dielectric materials, the difference between λ _off and λ _on can be less than or equal to 31 nm. When the filter layer 50 contains more than 12 pairs of dielectric material pairs, the difference between λ _off and λ _on can be less than or equal to 11 nm, that is to say, the filter layer 50 contains more than 12 pairs of dielectric material pairs can have A narrower light transition band can achieve a more effective filtering and purification effect. With the low-pass filter function of the filter layer 50 , the light emitted by the light-emitting element 1 can be filtered out in a specific wavelength range greater than λ _off , thereby further achieving the effect of light purification. Similarly, when the filter layer 50 has a high-pass filter function, it has a transmittance of more than 95% for a light with a wavelength greater than _λon , and a transmittance of less than 5% for a light with a wavelength less than _λoff . When the filter layer 50 has a band-pass filter function, it has a transmittance of more than 95% for a light with a wavelength between λ _on1 and λ _on2 , and a transmittance of less than 5% for a light with a wavelength less than λ _off1 . A light with a wavelength greater than λ _off2 has a transmittance of less than 5%, where λ _off1 <λ _on1 <λ _on2 <λ _off2 .

The reflection structure 16 is located on the second surface 10b of the substrate to reflect the light emitted by the semiconductor stack 12, so that the light is mainly extracted through the upper surface of the light emitting element 1 (ie, the surface where the filter layer 50 is located). In one embodiment, the reflective structure 16 includes a metal reflective layer, wherein the metal material can be selected from materials with high reflectivity for the light emitted by the semiconductor stack 12 , such as aluminum, silver, and the like. In another embodiment, the reflective structure 16 may include a stacked structure, wherein the stacked structure includes a pair or a plurality of pairs of sub-layers with different refractive indices stacked alternately. The material of each sub-layer of the laminated structure includes a material with light transmittance, such as a conductive material or an insulating material. The conductive material includes metal oxides such as indium tin oxide (ITO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), zinc oxide (ZnO), indium zinc oxide (IZO), and the like. The insulating material includes organic material or inorganic material, wherein the inorganic material includes silica gel, glass or dielectric material, etc. Through the selection of materials with different refractive indices and the thickness design, the reflective structure 16 can provide a reflection function for light in a specific wavelength range. In one embodiment, the reflection structure 16 is, for example, a distributed Bragg reflector (DBR). In another embodiment, the reflective structure 16 includes a dielectric material stack and a metal layer (not shown) to form an omnidirectional reflector (ODR). In another embodiment, the reflection structure 16 may be omitted.

The light emitted by the semiconductor stack 12, such as a first light, is a single color light, such as blue light, green light, blue-green light, yellow light or red light. A second light is obtained through the filter layer 50, and the color is the same as that of the first light. The second light is extracted from the upper surface of the light-emitting element 1 . The second ray has a smaller full width at half maximum (FWHM) than the first ray. In one embodiment, the second light obtained through the filter layer 50 has the same color as the first light, and its peak wavelength is consistent with or similar to the peak wavelength of the first light, or the wavelength range of the first light and the second light. overlap, and the second ray has a smaller half-height width than the first ray. In one embodiment, part of the first light emitted by the semiconductor stack 12 is extracted from the upper surface through the light filter layer 50 , that is, the second light; the other part of the first light is unfiltered from the side of the light-emitting element 1 . Layer 50 is extracted. The light extracted from the side surface of the light-emitting element 1 without the filter layer 50 has a peak wavelength and a half-width that are consistent with or similar to the first light. In one embodiment, for a light with a peak wavelength of λ _p nm, the filter layer 50 has a transmittance of more than 80% at λ _p nm, more preferably, a transmittance of more than 90%. The transmittance of the filter layer 50 for light with wavelengths above (λ _p +Δλ) nm is less than 50%, and/or the transmittance for light with wavelengths below (λ _p -Δλ) nm is less than 50%. The Δλ can be determined according to the user's requirements for the filter effect and the light intensity of the light-emitting element, and the filter layer 50 can be designed by selecting sub-layer materials with different refractive indices and their thicknesses.

FIG. 3 shows experimental results simulated according to an embodiment of the present application. In FIG. 3, the curve L1 represents the wavelength spectrum of the light actually emitted by the semiconductor stack 12, which is the first light; the curve F1 represents the transmittance of the filter layer 50 to light of different wavelengths; and the curve L2 represents the combination of the semiconductor stack 12 with the filter The simulated wavelength spectrum obtained by the layer 50 is the simulated wavelength spectrum of the second light obtained after the first light passes through the filter layer 50 . In this experiment, the first light emitted by the semiconductor stack 12 is green light with a peak wavelength of 532 nm. The filter layer 50 includes a plurality of pairs of dielectric material pairs composed of SiO ₂ and TiO ₂ , wherein, there are three sets of dielectric material stacks, the first set of dielectric material stacks is closer to the semiconductor stack 12 , and the second set of dielectric material stacks is closer to the semiconductor stack 12 . The dielectric material stack is further away from the semiconductor stack 12, and the third set of dielectric material stacks is interposed between the first and second sets of dielectric material stacks. Wherein, the optical thickness of the SiO _{2 and TiO 2 dielectric material pair of the first group is greater than that of the third group of SiO 2 and TiO 2 dielectric material} pairs; the optical thickness of the second group SiO ₂ and TiO ₂ dielectric material pair The optical thickness is greater and/or less than the optical thickness of the _SiO2 and _TiO2 dielectric material pair of the third group. The first group of _SiO2 and _TiO2 dielectric material pairs contains integer or non-integer pairs, the second group of _SiO2 and _TiO2 dielectric material pairs contains integer or non-integer pairs, and the third group of _SiO2 and TiO2 ₂ Dielectric material pairs include integer pairs or non-integer pairs. The number of dielectric material pairs in the third set of dielectric material stacks is greater than the number of dielectric material pairs in the first and second sets of dielectric material stacks, respectively. By adjusting the thicknesses of the first group and the second group of dielectric material stacks, the phenomenon of reducing the transmittance in a part of the wavelength range caused by the interference phenomenon can be reduced.

As shown in FIG. 3 , the filter layer 50 has a transmittance of over 80% for this peak wavelength; more preferably, the filter layer 50 has a transmittance of over 90% for this peak wavelength. The transmittance of the filter layer 50 for light with wavelengths above 550 nm is less than 50%, and the transmittance for light with wavelengths below 535 nm is greater than or equal to 80%. In addition, the first light passes through the light filter layer 50 to obtain a second light. The second light is also green light, but has a smaller half-height width than the first light. The filter layer 50 filters out the light of the first light in a specific wavelength band. In this experiment, by virtue of the low transmittance of the first light above 550 nm by the filter layer 50, most of the light above 550 nm is filtered out, so that the wavelength spectrum of the second light is higher than that of the first light. Symmetrical, with a half-height less than the first ray. In one embodiment, the width at half maximum of the second light is less than or equal to 25 nm. More preferably, the full width at half maximum of the second light is less than or equal to 20 nm. In this way, the color purity of the light emitted by the light-emitting element 1 can be improved.

In another embodiment, for light with a peak wavelength of λ _p nm, such as green light with a wavelength of 532 nm, the filter layer 50 has a band-pass filter function, and has a transmittance of more than 80% for this peak wavelength. The transmittance of light above 550 nm is less than 50%, and the transmittance of light with wavelength below 510 nm is less than 50%. Most of the light with wavelengths above 550 nm and the light with wavelengths below 510 nm are filtered out by the filter layer 50 .

FIG. 4 shows a cross-sectional view of the light-emitting element 2 according to the second embodiment of the present application. The difference from the light-emitting element 1 is that the light-emitting element 2 includes a plurality of light-emitting units electrically connected in series. This embodiment takes the light-emitting element 2 having two light-emitting units 11a and 11b as an example, and the light-emitting units 11a and 11b are located on the first surface 10a of the substrate separated from each other. The light-emitting units 11a and 11b respectively have a semiconductor stack 12 and a transparent conductive layer 18, an insulating layer 36 is located between the light-emitting units 11a and 11b, and covers the first surface 10a of the substrate, the sidewalls of the first semiconductor layer 121 of the light-emitting unit 11a, and the light-emitting unit 11b The sidewalls of the semiconductor stack 12 and a part of the upper surface of the second semiconductor layer 122 . The connection electrode 60 is located on the insulating layer 36, one end of which contacts the first semiconductor layer 121 of the light-emitting unit 11a, and the other end contacts the transparent conductive layer 18 of the light-emitting unit 11b. In this way, the light-emitting units 11a and 11b are electrically connected in series. In another embodiment, the connecting electrode 60 is electrically connected to the first semiconductor layer 121 on the light emitting units 11a and 11b, and/or the connecting electrode 60 is electrically connected to the second semiconductor layer 121 on the light emitting units 11a and 11b, so that light is emitted The units 11a and 11b form different light-emitting unit arrays such as parallel, series, or series-parallel.

The first electrode 20 is located on the first semiconductor layer 121 of the light emitting unit 11b, and the second electrode 30 is located on the second semiconductor layer 122 of the light emitting unit 11a. The filter layer 50 covers the light emitting units 11a and 11b, the connection electrodes 60, and the first surface 10a of the substrate between the light emitting units 11a and 11b. Similar to the light-emitting element 1 of the first embodiment, the filter layer 50 of the light-emitting element 2 has openings 501 and 502 to expose the first electrode 20 and the second electrode 30, respectively. The function, structure and material of the filter layer 50 are the same as those described above, and will not be repeated here. The first light emitted by the semiconductor stack 12 in the light-emitting element 2 passes through the filter layer 50 to obtain the second light, which is extracted from the upper surface of the light-emitting element 2 (ie, the surface where the filter layer 50 is located). Wherein, the second light ray has the same color as the first light ray, and has a smaller half-height width than the first light ray. In this way, the color purity of the light emitted by the light-emitting element 2 can be improved. In one embodiment, the second light is green light, and its full width at half maximum is less than or equal to 25 nm. More preferably, the full width at half maximum of the second light is less than or equal to 20 nm.

FIG. 5 shows a cross-sectional view of the light-emitting element 3 according to the third embodiment of the present application. Different from the light-emitting element 1 and the light-emitting element 2, the light-emitting element 3 is a flip-chip element, and the first electrode 20' and the second electrode 30' of the light-emitting element 3 are connected to a carrier in a flip-chip manner (not shown in the figure), the light-emitting element 3 is connected with the circuit (not shown in the figure) on the carrier board, so as to achieve the connection with external electronic components or external power supply. In addition, unlike the light emitting element 1 and the light emitting element 2, the light filter layer 50 of the light emitting element 3 is formed on the semiconductor stack 12 and located on the second surface 10b of the substrate. The functions, structures and materials of the filter layer 50 are the same as those in the previous embodiments, and are not described in detail here.

The light-emitting element 3 includes a reflective structure 28 covering the transparent conductive layer 18 . The reflective structure 28 may include a metal reflective layer, such as a single layer of metal or a stack of multiple layers of metal. In one embodiment, the reflective structure 28 includes a barrier layer (not shown) and a reflective layer (not shown). The barrier layer is formed and covers the reflective layer. The barrier layer can prevent the migration of metal elements in the reflective layer. , diffusion or oxidation. The material of the reflective layer includes a metal material having high reflectivity for the light emitted by the semiconductor stack 12, such as silver (Ag), gold (Au), aluminum (Al), titanium (Ti), chromium (Cr), copper ( Cu), nickel (Ni), platinum (Pt), ruthenium (Ru) or alloys or stacks of the above materials. The material of the barrier layer includes chromium (Cr), platinum (Pt), titanium (Ti), tungsten (W), zinc (Zn) or alloys or stacks of the above materials. The light emitted by the semiconductor stack 12 is extracted from the upper surface of the light-emitting element 3 (ie, the surface on which the filter layer 50 is located) through the reflection of the reflective structure 28 , thereby increasing the brightness of the light-emitting element 3 .

The light-emitting element 3 includes a protective layer 26 covering the semiconductor stack 12 and sidewalls of the semiconductor stack 12 . In one embodiment, the protective layer 26 can further cover the first surface 10 a of the substrate. The protective layer 26 includes openings 261 and 262 to expose the first semiconductor layer 121 and the reflective structure 28, respectively. The material of the protective layer 26 is a non-conductive material, including organic materials, such as Su8, benzocyclobutene (BCB), perfluorocyclobutane (PFCB), epoxy resin (Epoxy), acrylic resin (Acrylic Resin), ring Olefin polymer (COC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide (Polyetherimide) or fluorocarbon polymer ( Fluorocarbon Polymer), or inorganic materials, such as Silicone, Glass, or dielectric materials, such as silicon oxide (SiO _x ), silicon nitride (SiN _x ), silicon oxynitride ( SiO _x N _y ), niobium oxide (Nb ₂ O ₅ ), hafnium oxide (HfO ₂ ), titanium oxide (TiO _x ), magnesium fluoride (MgF ₂ ), aluminum oxide (Al ₂ O ₃ ), and the like. In one embodiment, the protective layer 26 is formed by alternately stacking a pair or a plurality of pairs of materials with different refractive indices. By selecting and designing the thicknesses of the materials with different refractive indices, the protective layer 26 forms a reflective structure that responds to a specific wavelength range. The light provided by the reflection function, such as a distributed Bragg reflector. When the protective layer 26 forms a reflective structure, the light emitted by the semiconductor stack 12 is extracted from the upper surface of the light-emitting element 3 (ie, the surface on which the filter layer 50 is located) through the reflection of the protective layer 26 , thereby increasing the number of light-emitting elements. 3 brightness.

In one embodiment, when the protective layer 26 is a reflective structure, the reflective structure 28 may be omitted.

The light-emitting element 3 includes a first electrode 20' and a second electrode 30'. The first electrode 20' is electrically connected to the first semiconductor layer 121 through the opening 261, and the second electrode 30' is electrically connected to the reflective structure 28, the transparent conductive layer 18 and the second semiconductor layer 122 through the opening 262. The first electrode 20' and the second electrode 30' include metal materials, such as chromium (Cr), titanium (Ti), tungsten (W), gold (Au), aluminum (Al), indium (In), tin (Sn) , nickel (Ni), rhodium (Rh), platinum (Pt) and other metals or a laminate or alloy of the above materials. The first electrode 20' and the second electrode 30' may be composed of a single layer or multiple layers. For example, the first electrode 20' and the second electrode 30' may include Ti/Au, Ti/Pt/Au, Cr/Au, Cr/Pt/Au, Ni/Au, Ni/Pt/Au or Cr/Al/Cr /Ni/Au etc.

In another embodiment, the light-emitting element 3 may include a plurality of light-emitting units formed on the substrate 10. Similar to the light-emitting element 2, an insulating layer is formed between adjacent light-emitting units to electrically connect the plurality of light-emitting units with connecting electrodes. Then, the protective layer 26 , the first electrode 20 ′ and the second electrode 30 ′ are formed again.

The first light emitted by the semiconductor stack 12 in the light-emitting element 3 passes through the substrate 10 and passes through the filter layer 50 to obtain the second light, which is emitted from the upper surface of the light-emitting element 3 (ie, the surface on which the filter layer 50 is located). pick out. Wherein, the second light ray has the same color as the first light ray, and has a smaller half-height width than the first light ray. In this way, the color purity of the light emitted by the light-emitting element 3 can be improved. In one embodiment, the second light is green light, and its full width at half maximum is less than or equal to 25 nm. More preferably, the full width at half maximum of the second light is less than or equal to 20 nm.

FIG. 6 shows a cross-sectional view of the light-emitting element 4 according to the fourth embodiment of the present application. The light-emitting element 4 is similar to the light-emitting element 3, except that the light-emitting element 4 does not have the substrate 10, and the filter layer 50 of the light-emitting element 4 is located on the second surface 121b of the first semiconductor layer 121, wherein the second surface 121b and the first surface 121a relatively. The functions, structures and materials of the filter layer 50 are the same as those in the previous embodiments, and are not described in detail here. The first light emitted by the semiconductor stack 12 in the light-emitting element 4 passes through the filter layer 50 to obtain the second light, which is extracted from the upper surface of the light-emitting element 4 (ie, the surface where the filter layer 50 is located). Wherein, the second light ray has a half-height width smaller than that of the first light ray. In this way, the color purity of the light emitted by the light-emitting element 4 can be improved. In one embodiment, the second light is green light, and its full width at half maximum is less than or equal to 25 nm. More preferably, the full width at half maximum of the second light is less than or equal to 20 nm.

FIG. 7A shows a cross-sectional view of the light-emitting element 5 according to the fifth embodiment of the present application. The light-emitting element 5 includes a first electrode 20'' and a second electrode 30'' respectively disposed on two opposite surfaces 121b and 122a of the semiconductor stack 12, and electrically connected to the first semiconductor layer 121 and the second semiconductor layer 122, respectively. The filter layer 50 covers the side surface of the semiconductor stack 12 and the second surface 121b of the first semiconductor layer, including the opening 501 to expose the first electrode 20''. In another embodiment (not shown), the filter layer 50 further covers On the side surface of the first electrode 20 ″, the opening 501 exposes the upper surface of the first electrode 20 ″. In another embodiment, the first electrode 20 ″ is located in the opening 501 and covers part of the surface 50e of the filter layer 50 . In one embodiment, the light-emitting element 5 further includes a conductive adhesive layer and/or a conductive substrate (not shown) located between the second semiconductor layer 122 and the second electrode 30 ″, and the semiconductor stack 12 uses the conductive adhesive layer and the conductive substrate. In another embodiment, as shown in Fig. 7B, the sequence of the semiconductor stack 12 is reversed from that of Fig. 7A. The filter layer 50 covers the side surface of the semiconductor stack 12 and the second semiconductor layer surface 122a, including the opening 501 exposed The second electrode 30". The first light emitted by the semiconductor stack 12 in the light-emitting element 5 passes through the filter layer 50 to obtain the second light, which is extracted from the top and side surfaces of the light-emitting element 5 (ie, the surface where the filter layer 50 is located). Wherein, the second light ray has the same color as the first light ray, and has a smaller half-height width than the first light ray. In this way, the color purity of the light emitted by the light-emitting element 5 can be improved. In one embodiment, the second light is green light, and its full width at half maximum is less than or equal to 25 nm. More preferably, the full width at half maximum of the second light is less than or equal to 20 nm. In another implementation (not shown), the filter layer 50 covers the surface 121 b or 122 a of the semiconductor stack 12 and does not cover the side surface of the semiconductor stack 12 . In one embodiment, when measuring the light-emitting elements of the above embodiments, in order to avoid light that does not pass through the filter layer 50, such as light interference extracted from the side of the light-emitting element that is not covered with the filter layer 50, the measurement is performed. In this case, an optical measuring sleeve can be used to collect and measure the light, so as to collect and measure the second light extracted by the filter layer 50 .

In the technical field, the wavelength with the highest light intensity in the wavelength spectrum of the light-emitting element is defined as the peak wavelength, and when measuring the color characteristics of a light, especially the color characteristics of visible light, the dominant wavelength of the color can be used. wavelength) or chromaticity coordinates. Those skilled in the art can understand that light with the same peak wavelength does not necessarily have the same dominant wavelength, that is, does not necessarily have the same color characteristics. When the dominant wavelength of a color light is closer to the peak wavelength, it means that the color purity of the color light is higher. Compared with the prior art, according to the light-emitting element of any embodiment of the present application, the dominant wavelength and the peak wavelength of the light emitted are closer, for example, the difference between the dominant wavelength and the peak wavelength of the light emitted by the light-emitting element is less than 3 nm, more preferably, less than 2 nm. 8A to 8C show experimental comparisons between the light-emitting element 3 according to the third embodiment of the present application and a light-emitting element of a comparative example. The difference between the light-emitting element 3 and the light-emitting element of the comparative example is that the light-emitting element of the comparative example does not have the filter layer 50 . In this experiment, the filter layer 50 includes a laminated structure as used in the simulation experiment of FIG. 3 . As shown in FIG. 8A , both the light-emitting element of the comparative example and the light-emitting element 3 emit green light with similar peak wavelengths, but compared with the light-emitting element of the comparative example, the light emitted by the light-emitting element 3 according to the third embodiment is half the Smaller height and width. In addition, the difference between the main wavelength and the peak wavelength of the light emitted by the light-emitting element 3 is 2.46 nm, which is smaller than the difference between the main wavelength and the peak wavelength of the light-emitting element of the comparative example 8.63 nm. In other words, the color purity of the light emitted by the light-emitting element 3 is high.

Figure 8B shows the color gamut distribution of the color gamut specification BT.2020 (also known as Rec. 2020) on the CIE 1931 chromaticity coordinates, and the forward light distribution of the comparative example light-emitting element and light-emitting element 3 on the CIE 1931 chromaticity coordinates . In FIGS. 8B and 8C , the light rays of the light-emitting element of the comparative example and the light-emitting element 3 are received and measured by an optical measurement sleeve. In order to clearly show the measured chromaticity coordinate values, FIG. 8C shows a partial enlarged view of the region R in FIG. 8B. 8B, the color gamut specification BT.2020 is defined on the CIE 1931 chromaticity coordinates, with pure red at (0.708, 0.292), pure green at (0.17, 0.797), and pure blue at (0.131, 0.046). Compared with the prior art, according to the light-emitting element of any embodiment of the present application, the color purity of the light emitted is higher, that is, closer to the coordinates of the pure color point in the above-mentioned color gamut specification. Generally speaking, when a light source to be measured is closer to the boundary of the color gamut on the chromaticity coordinates (ie, the horseshoe-shaped spectral locus as shown in FIG. 8B ), the higher the color purity is. Color purity can be expressed as a percentage, defined on the CIE chromaticity coordinates, the linear distance between the chromaticity coordinates of the light source to be measured and the chromaticity coordinates of the energy white point and the spectral locus from the white point light source to the dominant wavelength of the light source to be measured Percentage of chromaticity coordinate distance. Taking the green light with a peak wavelength between 525 nm and 535 nm emitted by the light-emitting element of any embodiment of the present application as an example, the green light has a chromaticity coordinate value (X1, Y1) based on the CIE 1931 chromaticity coordinate, wherein X1 ≦ 0.2, Y1 ≧ 0.75. Referring to FIG. 8C , Group_Ref_1 is the data point measured by the light-emitting element of the comparative example with the peak wavelength of light emitted at 530 nm, Group_Ref_2 is the data point measured by the light-emitting element of the comparative example with the peak wavelength of light emitted at 532 nm, and Group_Exp_1 is The data points measured by the light-emitting element 3 whose peak wavelength of emitted light is 530 nm, and Group_Exp_2 are the data points measured by the light-emitting element 3 whose peak wavelength of emitted light is 532 nm. Compared with the light-emitting element of the comparative example with the same peak wavelength of light, the green light emitted by the light-emitting element 3 according to the third embodiment is closer to the pure green coordinate (0.17, 0.797) and has higher color purity. Taking the green light with a peak wavelength between 525 nm and 535 nm emitted by the light-emitting element of any embodiment of the present application as an example, the color purity is greater than or equal to 92%. More preferably, greater than or equal to 93%.

FIG. 9 shows the wavelengths and light intensities of the light-emitting element 3 according to the third embodiment of the present application measured at different angles. In this experiment, the light-emitting element 3 is as described in the above-mentioned embodiment, the filter layer 50 is located on the second surface 10b of the substrate, and the light emitted by the light-emitting element 3 includes forward light and side light, wherein the light intensity of the forward light is The light intensity is greater than the light intensity of the lateral light, and the full width at half maximum of the forward light is smaller than that of the lateral light. The light emitted by the light-emitting element 3 includes the light emitted in a first direction, which includes the light emitted through the lateral light, and has a first half-height width and a first light intensity; the light emitted by the light-emitting element 3 includes a second The light emitted in the direction includes the light emitted through the forward direction, and has a second half width and a second light intensity. In one embodiment, since the filter layer 50 is located on the second surface 10b of the substrate, the sidewall between the second surface 10b of the substrate and the first surface 10a is not covered with the filter layer 50, so the difference between the first direction and the light extraction surface is not covered by the filter layer 50. The light in the first direction measured when the angle between the normal directions is in the range of 45-90 degrees includes the light that is not extracted from the side surface of the light-emitting element 3 (eg, the sidewall of the substrate) through the filter layer 50 . The light in the second direction measured when the angle between the second direction and the normal direction of the light extraction surface is in the range of 0-30 degrees includes the light exiting through the forward direction. In this experiment, relative to the light in the first direction, the second half width of the light in the second direction is smaller than the first half width and less than or equal to 25 nm, and the second light intensity is greater than the first light intensity. The light extraction surface here is the surface 50e of the filter layer 50 relative to the semiconductor stack 12 . The above experiment takes a green light-emitting element as an example. However, according to any embodiment of the present application, the semiconductor stack of the light-emitting element can emit red light, yellow light, blue light or blue-green light, and the filter is designed according to these colors. The layered structure of the layer 50 can obtain purified red light, yellow light, blue light or blue-green light, and achieve the same effect as described above. The color purity of the light-emitting element, especially the color purity of the forward light, is improved by the filter layer 50, which is helpful for specific product applications. For example, applying the light-emitting element according to any embodiment of the present application to a display device can achieve high color saturation, high contrast, and wide color gamut.

The light emitted in the forward direction is the light extracted by the filter layer 50 , which purifies the light generated by the semiconductor stack 12 through the filter properties of the filter layer 50 . In this embodiment, the light emitted from the side, such as the light in the first direction, includes the light that is not extracted by the filter layer 50 , such as the light extracted from the side of the light-emitting element, which is close to the light generated by the original semiconductor stack 12 . characteristics, such as having a half-height width close to that of the light generated by the original semiconductor stack 12 . However, this application is not limited to this. In order to further reduce the effect of the lateral light not extracted by the filter layer 50 on the light purification, in one embodiment, a modulation structure (not shown) can also be formed on the side surface of the light-emitting element according to any embodiment of the present application. In one embodiment, the modulation structure includes a reflective layer, which reflects or changes the direction of the light emitted to the side of the light-emitting element to become the light emitted in the forward direction. In another embodiment, the modulation structure includes a light absorbing layer for absorbing light emitted to the side of the light-emitting element. In another embodiment, the modulation structure includes a filter layer, which is similar in function to the filter layer 50 to allow only light in a specific wavelength band to pass through. In another embodiment, the modulation structure includes a light blocking layer to block light from being extracted from the side of the light-emitting element. In one embodiment, the modulation structure can be used in conjunction with the application end of the back-end packaging module. For example, the modulation structure is arranged on the side surface of the light-emitting element in the package. The structure of the light-emitting element package will be described in detail later.

FIG. 10A is a schematic top view of a display device 101 according to an embodiment of the present application. As shown in FIG. 10 , the display device 101 includes a display substrate 200 , wherein the display substrate 200 includes a display area 210 and a non-display area 220 , and a plurality of pixels PX are arranged in the display area 210 in the display substrate 200 . PX respectively includes a first sub-pixel PX_A, a second sub-pixel PX_B and a third sub-pixel PX_C. The data line driving circuit 130 and the scanning line driving circuit 140 are disposed in the non-display area 220 . The data line driving circuit 130 is connected to a data line (not shown) of each pixel PX, so as to transmit data signals to each pixel PX. The scan line driving circuit 140 is connected to a scan line (not shown) of each pixel PX, so as to transmit a scan signal to each pixel PX. The pixel PX includes the light-emitting element of any of the foregoing embodiments, and the surface 50e of the filter layer 50 opposite to the semiconductor stack 12 is used as the main light extraction surface. In one embodiment, in order to realize a high-resolution display device, it is usually necessary to provide small-sized and high-density pixels, so the diagonal length of the light-emitting element of any sub-pixel is less than 300 μm.

Each sub-pixel emits light of different colors. In one embodiment, the first sub-pixel PX_A, the second sub-pixel PX_B and the third sub-pixel PX_C are, for example, red sub-pixels, green sub-pixels and blue sub-pixels, respectively. Dice pixel. Light-emitting elements that emit light of different wavelengths can be selected as sub-pixels respectively, so that each sub-pixel presents different colors. The display device 101 emits a full-color image through the combination of red, green, and blue light emitted by each sub-pixel. Referring to FIG. 8B again, when the color light emitted by the light-emitting elements in each sub-pixel is closer to the solid color point coordinates formulated by the color gamut specification based on the chromaticity coordinates, the wider the color gamut range that the pixel can present, that is, it can be A display device that realizes a wide color gamut. In the conventional display device, in order to achieve high color saturation, high contrast, or wide color gamut, it is necessary to provide filter elements or wavelength conversion elements in addition to the light-emitting elements in the pixels, which may increase the process complexity of the overall display device. , production cost and structural complexity. Furthermore, the use of filter elements or wavelength conversion elements may lose the brightness or light intensity of the light emitting element. The display device fabricated according to the light-emitting element of any embodiment of the present application can improve the above-mentioned problems.

In this embodiment, the number, area and arrangement of sub-pixels of a single pixel PX are not limited to this, and different implementations can be implemented according to different requirements of users such as color and resolution. According to a display device (not shown) according to another embodiment of the present application, the pixel PX further includes a fourth sub-pixel, and the fourth sub-pixel includes the light-emitting element of any of the foregoing embodiments. The light wavelengths of the light-emitting elements included in the fourth sub-pixel are different from the light-emitting elements in the first to third sub-pixels. For example, the fourth sub-pixel is a blue-green sub-pixel, and the light-emitting element in the fourth sub-pixel emits light with a peak wavelength ranging from 495 nm to 520 nm. More preferably, between 500 nm and 510 nm. Similarly, the light-emitting element in the fourth sub-pixel purifies the blue-green light emitted by the semiconductor stack through the filter layer 50 to obtain blue-green light with higher color purity, thereby improving the color rendering capability of the display device.

In one embodiment, FIG. 10B is a schematic cross-sectional view of one pixel PX in FIG. 10A . Any sub-pixel includes a light-emitting element package 6, and the light-emitting element package 6 encapsulates the light-emitting element 3 of the third embodiment or the light-emitting element 4 of the fourth embodiment. The light emitting element package 6 is bonded to the display substrate 200 . The circuit layer 110 and the circuit bonding pads 8 a and 8 b are disposed on the display substrate 200 . The circuit layer 110 and the circuit bonding pads are electrically connected, and the circuit layer 110 may include active electronic components, such as transistors. The electrodes 81 and 83 of the light-emitting element package 6 are respectively bonded to the circuit bonding pads 8 a and 8 b by, for example, soldering, and are electrically connected to the display driving circuit (ie, the data line driving circuit 130 and the scanning line driving circuit 140 ) through the circuit layer 110 . sexual connection. In this way, the light-emitting elements in the pixels PX can be controlled by the data line driving circuit 130 , the scanning line driving circuit 140 and the circuit layer 110 .

FIG. 10C shows a light-emitting element package 6 according to an embodiment of the present application. As mentioned above, the light-emitting element package 6 encapsulates the light-emitting element 3 of the third embodiment. The light emitting element package 6 includes the encapsulation material 90 covering the side surfaces of the light emitting element 3 . In one embodiment, the packaging material 90 includes a matrix, such as silicone, epoxy, acrylic or a mixture thereof. In another embodiment, the packaging material 90 includes a substrate and other materials to form the aforementioned modulation structure. For example, the encapsulation material 90 includes a base material and a light-absorbing material to form a light-absorbing layer, wherein the light-absorbing material includes a black material, such as carbon black. For example, the packaging material 90 includes a base material and a reflective material to form a reflective layer, wherein the reflective material includes titanium oxide (TiO _x ), silicon oxide (SiO _x ) or a mixture thereof. In another embodiment, the encapsulation material 90 includes a plurality of modulation structures with different functions. For example, the encapsulation material 90 includes a reflective layer covering the light-emitting element, and a light absorbing layer covering the reflective layer.

In another embodiment (not shown), the pixel PX includes a light-emitting element package 6, and a single light-emitting element package 6 simultaneously encapsulates a plurality of light-emitting elements, and each light-emitting element constitutes a sub-pixel. In one embodiment, the encapsulation material 90 of the light-emitting element package 6 forms a modulation structure and is filled between a plurality of light-emitting elements. FIG. 10B exemplarily shows that the light-emitting element package 6 is encapsulated with a flip-chip light-emitting element according to an embodiment of the present application, but the light-emitting element package of the present application is not limited thereto. In other embodiments (not shown), any sub-pixel includes the light-emitting element according to any embodiment of the present application, and the light-emitting element is bonded to the light-emitting element in a wire bonding method, soldering method or die-bonding method suitable for the light-emitting element of different embodiments. The first electrode 20 (20' or 20") and the second electrode 30 (30' or 30") are electrically connected to the circuit bonding pads 8a and 8b on the display substrate 200, respectively.

FIG. 11 is a cross-sectional view of a light-emitting element 9 according to a sixth embodiment of the present application. The light-emitting element 9 in FIG. 11 is only taken as an example similar to the light-emitting element 1 in FIG. 1. The main structure of the light-emitting element 9 and the light-emitting element 1 are similar, and the difference lies in the filter layer 50'. However, the main structure of the light-emitting element 9 may be the same as any of the light-emitting elements in the foregoing embodiments. The light-emitting element 9 includes a filter layer 50', which is formed by alternately stacking one or more pairs of material layers with different refractive indices. The filter layer 50 ′ has a similar structure to the aforementioned filter layer 50 , by selecting different refractive index dielectric materials as the first sub-layer and the second sub-layer (not shown) in the filter layer 50 ′, and matching them The thickness is designed to form an interference phenomenon, so that the light emitted by the light emitting element 9 can be selectively transmitted or reflected through the filter layer 50 ′. The difference is that the filter layer 50' provides a filtering function for light in a specific angle range, that is, only light in a specific angle range can penetrate the filter layer 50'. Specifically, as shown in the light-emitting element 9 shown in FIG. 11 , the semiconductor stack 12 emits a light with a specific peak wavelength and is incident on the filter layer 50 ′. And reflect most of the large angle incident light. In another example, the structure of the light-emitting element 9 is similar to that of the light-emitting element 3 in the foregoing embodiment, and the light emitted by the semiconductor stack 12 passes through the substrate 10 and enters the filter layer 50 ′. Small-angle incident light penetrates, and most large-angle incident light is reflected. The angle of the incident light here refers to the angle between the direction of the incident light and the normal direction of the incident surface. In one embodiment, FIG. 12 shows a schematic diagram of the light path of the light emitting element 9 . The light path of the incident light at a small angle is the same as P1, and the light emitted from the active layer 123 passes through the filter layer 50' and is extracted from the surface 50e' of the filter layer. The light path of the large-angle incident light is the same as P2, and the light emitted from the active layer 123 is totally reflected at the interface between the semiconductor stack 12 and the filter layer 50', toward the substrate 10, and the patterned structure ( Not shown) to produce refraction and/or scattering, and change the direction, forming a small angle incident light at the interface between the semiconductor stack 12 and the filter layer 50', and extracting from the filter layer surface 50e'. In this way, the filter layer 50' can make the light-emitting angle of the light emitted by the light-emitting element 9 converge, so as to achieve the effect of converging the light-emitting angle.

The light emitted by the light-emitting element 9 includes forward light and side light, wherein the light intensity of the forward light is greater than the light intensity of the side light. In one embodiment, the light transmittance of the filter layer 50' is greater than 90% when the incident angle is less than 10 degrees; and the light transmittance is less than 10% when the incident angle is greater than 20 degrees. According to the light-emitting element 9 of the sixth embodiment, the divergence angle (or also called the beam angle) is less than or equal to 120 degrees; in another embodiment, the divergence angle of the light-emitting element 9 is less than or equal to 110 degrees. In another embodiment, the divergence angle of the light-emitting element 9 ranges from 50 degrees to 110 degrees. In another embodiment, the divergence angle of the light-emitting element 9 is between 50 degrees and 100 degrees. Divergence angle means that in the light distribution curve of the light source, that is, in the spatial distribution of the luminous intensity of the light-emitting element at each angle, the light intensity reaches half of the light intensity in the normal direction of the light-emitting surface, and the angle formed by the two sides .

FIG. 13 shows the spatial distribution of the luminous intensity at various angles of the light-emitting element 9 of the sixth embodiment and the light-emitting element of the comparative example. The structure of the light-emitting element 9 of the sixth embodiment is similar to that of the light-emitting element 1. The filter layers 50 and 50' are formed by alternately stacking a first sub-layer and a second sub-layer composed of a pair or a plurality of pairs of materials with different refractive indices. The optical layer 50', like the optical filter layer 50, can selectively reflect and transmit certain incident light. The refractive index and thickness of the first sub-layer and the second sub-layer in the filter layer 50 are set to allow light in a specific wavelength range to penetrate, providing a filtering function. large light intensity. The refractive indices and thicknesses of the first sub-layer and the second sub-layer in the filter layer 50' are set to allow light in a specific incident angle range to penetrate. greater light intensity. In one embodiment, the transmittance of the incident light is more than 90% at the incident angle less than 10 degrees, and the transmittance is less than 10% (or the reflectivity reaches more than 80%) at the incident angle greater than 20 degrees. . In one embodiment, the filter layer 50 ′ includes a plurality of pairs of dielectric material pairs composed of SiO ₂ and TiO ₂ , wherein there are three sets of dielectric material stacks, and the first set of dielectric material stacks is closer to the semiconductor. For the stack 12, the second set of dielectric material stacks is further away from the semiconductor stack 12, and the third set of dielectric material stacks is interposed between the first and second sets of dielectric material stacks. Wherein, the optical thickness of the SiO _{2 and TiO 2 dielectric material pair of the first group is greater than that of the third group of SiO 2 and TiO 2 dielectric material} pairs; the optical thickness of the second group SiO ₂ and TiO ₂ dielectric material pair The optical thickness is greater and/or less than the optical thickness of the _SiO2 and _TiO2 dielectric material pair of the third group. The first group of _SiO2 and _TiO2 dielectric material pairs contains integer or non-integer pairs, the second group of _SiO2 and _TiO2 dielectric material pairs contains integer or non-integer pairs, and the third group of _SiO2 and TiO2 ₂ Dielectric material pairs include integer pairs or non-integer pairs. The number of dielectric material pairs in the third set of dielectric material stacks is greater than the number of dielectric material pairs in the first and second sets of dielectric material stacks, respectively. By adjusting the thicknesses of the first group and the second group of dielectric material stacks, it is possible to reduce the phenomenon that the transmittance in a part of the angle range decreases due to the interference phenomenon. The structure of the light-emitting element of the comparative example is similar to that of the light-emitting element 9, except that it does not have the filter layer 50'. It can be seen from FIG. 13 that, compared with the comparative example, the light-emitting element 9 of the sixth embodiment has higher light intensity at 60 degrees to 120 degrees, and has higher forward light; The normal direction of 50e' is within about plus or minus 30 degrees, the light-emitting element 9 of the sixth embodiment has a high light intensity and can concentrate the light in the positive direction. In addition, the divergence angle of the light-emitting element 9 of the sixth embodiment is 101 degrees, which is smaller than the divergence angle of the light-emitting element 9 of the comparative example, which is 139 degrees.

As in the previous embodiment, in another embodiment, a modulation structure (not shown) can also be formed on the side surface of the light-emitting element 9 of the sixth embodiment. In one embodiment, the modulation structure includes a reflective layer, which reflects or changes the direction of the light emitted to the side of the light-emitting element to become the light emitted in the forward direction. In another embodiment, the modulation structure includes a light absorbing layer for absorbing light emitted to the side of the light-emitting element. In another embodiment, the modulation structure includes a filter layer, which functions similarly to the filter layer 50' to allow only light at a specific angle to penetrate. In another embodiment, the modulation structure includes a light blocking layer to block light from being extracted from the side of the light-emitting element.

FIG. 14 is a schematic diagram of a sensing module 201 . As shown in FIG. 14 , the sensing module 201 includes a carrier board 400 , a light-emitting element package 6 ′ in which the light-emitting element 9 according to any embodiment of the present application is encapsulated, and a light-sensing element 40 is located between the carrier board 400 . On the surface, the light-emitting element 9 and the light-sensing element 40 are electrically connected to a circuit (not shown) on the carrier board 400 . The structure of the light-emitting element package 6' is similar to that of the aforementioned light-emitting element package 6, and is not repeated here. The light emitting element package 6 ′ and the light emitting element 9 in FIG. 14 are bonded to the carrier board 400 by flip chip with a structure similar to the light emitting element 3 as an example. However, different wire bonding methods can be selected according to the light emitting elements of different embodiments. The light-emitting element 9 is fixed on the carrier board 400 by a soldering method or a die-bonding method, and is electrically connected to the circuit on the carrier board 400 . The light sensing element 40 includes a photodiode. A light blocking element 80 can be further arranged between the light sensing element 40 and the light emitting element package 6' or the light emitting element 9 to avoid interference between the two, for example, to prevent the light emitted by the light emitting element 9 from being directly affected by the light sensing element 40 received.

The sensing module 201 is applied to a physiological sensing device. For example, the light emitted by the light-emitting element 9 is irradiated on the user's body to generate a reflection signal. The light-sensing element 40 receives the reflection signal to obtain a measurement signal, and then obtains the physiological information of the user through the operation of the circuit. , such as heartbeat, blood oxygen, blood pressure, blood sugar, water, or sweat. In order to measure accurate physiological information, the light emitted by the light-emitting element 9 is preferably concentrated and has a certain light intensity. According to the sensing module 201 of the embodiment of the present application, the light-emitting element 9 having the filter layer 50' is used, because the filter layer 50' can converge the light-emitting angle of the light-emitting element, without the assistance of additional optical elements such as lenses , a more concentrated light source can be obtained. In addition, the lack of additional optical elements also enables the sensing module 201 to have a lighter and thinner volume, which is suitable for users to wear.

In another embodiment, the light-emitting element 9 can also be applied to the display device 101 as shown in FIG. 10A and the pixel PX as shown in FIG. 10B . By converging the light-emitting angles of the light-emitting elements by the filter layer 50', the light-emitting angles of the light-emitting elements in the plurality of pixels PX of the overall display device 101 are uniform, thereby improving the uniformity of the display device 101 screen.

However, the above-mentioned embodiments are merely illustrative to illustrate the principles and effects of the present application, and are not intended to limit the present application. Anyone with ordinary knowledge in the technical field to which this application pertains can make modifications and changes to the above embodiments without departing from the technical principles and spirit of this application. All equivalent changes and modifications made in accordance with the shape, structure, feature and spirit described in the scope of the patent application of the present application shall be included in the scope of the patent application of the present application.

1, 2, 3, 4, 5, 9: light-emitting elements 6, 6': Light emitting element package 8a, 8b: circuit bond pads 10: Substrate 10a: the first surface of the substrate 10b: The second surface of the substrate 11a, 11b: light-emitting unit 101: Display device 201: Sensing module 110: circuit layer 130: Data line driver circuit 140: Scan line driver circuit 12: Semiconductor stack 121: the first semiconductor layer 121a: first surface 121b: Second surface 122: the second semiconductor layer 122a: the surface of the second semiconductor layer 123: Active layer 16: Reflective Structure 18: Transparent conductive layer 20, 20', 20": the first electrode 30, 30', 30": the second electrode 26: Protective layer 261, 262: protective layer opening 36: Insulation layer 40: Light sensing element 50, 50': filter layer 50a: first sublayer 50b: Second sublayer 50c: Third sublayer 50d: Fourth sublayer 50e, 50e': filter layer surface 501, 502: Opening 60: Connect electrodes 80: Light blocking element 81, 83: Electrodes 90: Encapsulation material 200: Display substrate 210: Display area 220: non-display area 400: carrier board PX: pixel PX_A, PX_B, PX_C: Subpixels P1, P2: light path

﹝ FIG. 1 ﹞ shows the light-emitting element 1 according to the first embodiment of the present application. ﹝ FIG. 2A and FIG. 2B ﹞ show a partial enlarged view of a cross-section of a filter layer in a light-emitting element according to an embodiment of the present application. ﹝ FIG. 3 ﹞ shows the experimental results simulated according to an embodiment of the present application ﹝ FIG. 4 ﹞ shows the light-emitting element 2 of the second embodiment of the present application. ﹝ FIG. 5 ﹞ shows the light-emitting element 3 according to the third embodiment of the present application. ﹝ FIG. 6 ﹞ shows the light-emitting element 4 according to the fourth embodiment of the present application. ﹝ FIG. 7A and FIG. 7B ﹞ show the light-emitting element 5 according to the fifth embodiment of the present application. ( FIGS. 8A to 8C ) show the experimental comparison of the light-emitting element 3 according to the third embodiment of the present application and a light-emitting element of a comparative example. ﹝ FIG. 9 ﹞ shows the wavelength and light intensity measured at different angles of the light-emitting element 3 according to the third embodiment of the present application. ﹝ FIG. 10A ﹞ shows a schematic top view of a display device 101 according to an embodiment of the present application. ﹝ FIG. 10B ﹞ shows a schematic cross-sectional view of a pixel PX according to an embodiment of the present application. ﹝ FIG. 10C ﹞ shows a schematic cross-sectional view of a light-emitting device package according to an embodiment of the present application. ﹝ FIG. 11 ﹞ shows the light-emitting element 9 according to the sixth embodiment of the present application. ﹝ FIG. 12 ﹞ shows a schematic diagram of the light path of the light-emitting element 9 according to the sixth embodiment of the present application. (Fig. 13) shows the light intensity distribution of the light-emitting element 9 of the sixth embodiment and the light-emitting element of the comparative example. ﹝ FIG. 14 ﹞ shows a schematic cross-sectional view of a sensing module according to an embodiment of the present application.

3: Light-emitting element

10: Substrate

10a: First surface

10b: Second surface

12: Semiconductor stack

121: the first semiconductor layer

122: the second semiconductor layer

123: Active layer

18: Transparent conductive layer

26: Protective layer

261, 262: Opening

28: Reflective Structure

20': first electrode

30': second electrode

50: filter layer

50e: filter layer surface

Claims (20)

A light-emitting element, comprising: a semiconductor stack; and a filter layer on the semiconductor stack, comprising a first surface facing the semiconductor stack and a second surface opposite to the first surface; Wherein: the light-emitting element emits a light; The light includes a first directional light with a first half-width, and a second directional light with a second half-width; The included angle between the first directional light and a normal direction of the second surface is 45-90 degrees, and the included angle between the second directional light and the normal direction of the second surface is 0-30 degrees; and The second half-height width is smaller than the first half-height width. The light-emitting element of claim 1, wherein the light has a main wavelength and a peak wavelength, and the difference between the main wavelength and the peak wavelength is less than 3 nm. The light-emitting element of claim 1, wherein the light has a peak wavelength ranging from 525 nm to 535 nm, and the light has a chromaticity coordinate value (X1, Y1) based on CIE 1931 chromaticity coordinates, wherein X1 ≦ 0.2, Y1 ≧ 0.75. The light-emitting element of claim 1, wherein the filter layer has a transmittance of more than 80% for a peak wavelength of the light. The light-emitting element of claim 1, wherein the second half width is less than or equal to 25 nm. The light-emitting element of claim 1, wherein the light intensity of the light in the second direction is greater than the light intensity of the light in the first direction. The light-emitting element of claim 1, wherein the filter layer comprises a first dielectric material layer and a second dielectric material layer which are alternately stacked. The light-emitting device of claim 1, further comprising a substrate between the semiconductor stack and the first surface, and the first surface faces the substrate. The light-emitting element of claim 1, further comprising a reflective structure located under the semiconductor stack and covering the semiconductor stack; and an electrode located under the reflective structure. The light-emitting element of claim 9, wherein the reflective structure comprises a metal reflective layer, and the electrode is electrically connected to the metal reflective layer. The light-emitting device of claim 9, wherein the reflective structure includes a dielectric material stack, the dielectric material stack includes an opening, and the electrode is electrically connected to the semiconductor stack through the opening. As in the light-emitting element of claim 1, it further includes: a substrate under the semiconductor stack; and an electrode on the semiconductor stack; Wherein, the filter layer includes an opening to expose the electrode. According to the light-emitting element of claim 1, the diagonal length of the light-emitting element is less than 300 μm. The light-emitting element of claim 1, wherein the light has a peak wavelength ranging from 525 nm to 535 nm, and the light has a color purity greater than or equal to 92%. A light-emitting element, comprising: a semiconductor stack emitting a first light; and a filter layer on the semiconductor stack, comprising a first surface facing the semiconductor stack and a second surface opposite to the first surface; Wherein: the first light obtains a second light through the filter layer; The first ray has a first half-width, the second ray has a second half-height; and The second half-width is smaller than the first half-width, and/or the second light has a half-width less than or equal to 25 nm. A display device includes a plurality of pixels, wherein one of the plurality of pixels includes any light-emitting element according to claim 1 to claim 15. A light-emitting element package comprising any light-emitting element according to claim 1 to claim 15. The light-emitting element package of claim 17, further comprising a modulation structure covering one side surface of the light-emitting element. The light-emitting element package of claim 18, wherein the modulation structure comprises a reflection layer, a light absorption layer, a light blocking layer or a light filter layer. A light-emitting element, comprising: a semiconductor stack emitting a first light; and a filter layer on the semiconductor stack, comprising a first surface facing the semiconductor stack and a second surface opposite to the first surface; Wherein: the filter layer includes a first dielectric material layer and a second dielectric material layer alternately stacked; The first light obtains a second light through the filter layer; and The light-emitting element has a divergence angle ranging from 50 degrees to 110 degrees.

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