CN108196396A

CN108196396A - Backlight module and liquid crystal display device

Info

Publication number: CN108196396A
Application number: CN201711489012.5A
Authority: CN
Inventors: 张捷
Original assignee: Xian Zhisheng Ruixin Semiconductor Technology Co Ltd
Current assignee: Xian Zhisheng Ruixin Semiconductor Technology Co Ltd
Priority date: 2017-12-29
Filing date: 2017-12-29
Publication date: 2018-06-22

Abstract

The present invention relates to a kind of backlight module and liquid crystal display device, including LED light source 611, quantum dot film 612, dielectric layer 615 and wire grating polarization layer 616；Wherein, the quantum dot film 612 is set on the LED light source 611；The dielectric layer 615 is set on the quantum dot film 612；The wire grating polarization layer 616 is set to the dielectric layer 615.LED backlight module light conversion ratio provided by the invention is high, can improve light emission luminance while the characteristic of high colour gamut of LED light source is realized.

Description

Backlight module and liquid crystal display device

Technical Field

The invention relates to the field of liquid crystal display, in particular to a backlight module and a liquid crystal display device.

Background

A Liquid Crystal Display (LCD) is one of flat panel displays, and is widely used in products such as televisions, computers, smart phones, mobile phones, car navigation devices, electronic books, and the like. Liquid crystal display devices have the advantages of low power consumption, small size, and low radiation, and are gradually replacing Cathode Ray Tube (CRT) display devices.

The current LED backlight structure utilizes blue LEDs to excite yellow or red and green fluorescent powder to form a white light backlight source. However, the phosphor has low luminous efficiency and wide spectral bandwidth, so that the liquid crystal display has bottlenecks in brightness and color gamut. The nanometer quantum dot is a latest semiconductor fluorescent material, has the advantages of higher luminous efficiency, longer service life, better color purity and the like, and is applied to a backlight module of an LCD in the form of an optical film. The backlight module structure formed by matching the quantum dot material with the blue LED light source is applied to a liquid crystal display to replace the traditional fluorescent powder to improve the luminous efficiency.

In the prior art, the liquid crystal display device still needs to use an absorption polarizer and a color photoresist in the structure, the structure limits the thickness of the liquid crystal display device, and is difficult to be thinner and lighter.

Disclosure of Invention

In order to solve the technical defects and shortcomings of the prior art, the invention provides a backlight module and a liquid crystal display device. The backlight module comprises an LED light source 611, a quantum dot film 612, a medium layer 615 and a metal wire grid polarizing layer 616; wherein,

the quantum dot film 612 is disposed on the LED light source 611;

the dielectric layer 615 is disposed on the quantum dot thin film 612;

the metal wire grid polarizer layer 616 is disposed on the dielectric layer 615.

In one embodiment of the present invention, the protective layer 613 and the first substrate 614 are further included; wherein,

the protective layer 613 is disposed on the quantum dot film 612;

the first substrate 614 is disposed between the protection layer 613 and the dielectric layer 615.

In one embodiment of the invention, the wire grid polarizer layer 616 includes a plurality of metal wires 6161; the metal lines 6161 are arranged on the dielectric layer 615 at intervals.

In one embodiment of the present invention, the dielectric layer 615 is a transparent dielectric layer and comprises SiO₂、SiO、MgO、Si₃N₄、TiO₂、Ta₂O₅Any one or more of them.

In one embodiment of the present invention, the first substrate 614 is a transparent substrate for supporting the medium layer 615 and the metal wire grid polarizer layer 616.

In one embodiment of the present invention, the quantum dot film 612 includes red quantum dots 6121, green quantum dots 6122, blue quantum dots 6123 and transparent photoresist 6124.

In one embodiment of the present invention, the quantum dot thin film 612 further includes a black matrix 6125.

In one embodiment of the present invention, the LED light sources 611 are bi-color LED chips.

In one embodiment of the invention, the bi-color LED chip includes a blue light source and a yellow light source.

Another embodiment of the present invention provides a liquid crystal display device, which includes a first electrode 62, a liquid crystal molecular layer 63, a second electrode 64, a second substrate 65, a polarizer 66, and a backlight module 61 according to any of the above embodiments.

Compared with the prior art, the invention has the following beneficial effects:

1. the backlight module provided by the invention adopts the metal wire grating polarizing layer to replace a polarizer, and utilizes the reflection characteristic of the metal wire grating polarizing layer to repeatedly excite the quantum dot film to emit light, so that the luminous efficiency of the backlight module is improved;

2. the backlight module provided by the invention utilizes the double-color LED chip as the light source of the backlight module, and the double-color LED chip integrates the blue light source and the yellow light source, so that the backlight module has the advantages of high luminous efficiency, small area and low cost.

Drawings

The following detailed description of embodiments of the invention will be made with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a backlight module according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a structure of a metal wire grid polarizer according to an embodiment of the present invention;

fig. 3 is a schematic diagram of an LED light source and a quantum dot thin film structure according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a liquid crystal display device according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a bicolor LED chip according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a blue light epitaxial layer according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a first active layer according to an embodiment of the invention;

fig. 8 is a schematic structural diagram of a yellow epitaxial layer according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a second active layer according to an embodiment of the invention;

FIG. 10 is a schematic structural diagram of an electrode according to an embodiment of the present invention;

fig. 11a to 11g are schematic diagrams illustrating a method for manufacturing a dual-color LED chip according to an embodiment of the invention.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.

Example one

Referring to fig. 1 to 3, fig. 1 is a schematic structural diagram of a backlight module according to an embodiment of the present invention; fig. 2 is a schematic diagram of an LED light source and a quantum dot thin film structure according to an embodiment of the present invention; fig. 3 is a schematic structural diagram of a metal wire grid polarizer layer according to an embodiment of the present invention.

This embodiment provides a backlight module 61, which includes an LED light source 611, a quantum dot thin film 612, a protection layer 613, a first substrate 614, a dielectric layer 615, and a metal wire grid polarization layer 616, which are sequentially stacked, as shown in fig. 1.

The metal wire grid polarizing layer 616 includes a plurality of strip-shaped metal wires 6161 with the same size, the metal wires 6161 are periodically arranged on the dielectric layer 615 at intervals, the metal wire grid polarizing layer 616 is configured to transmit TM polarized light with a vibration direction perpendicular to the metal wires, and is configured to reflect TE polarized light with a polarization direction parallel to the metal wires 6161, and the reflected TE polarized light passes through the quantum dot film 612 to excite the quantum dot film 612 to emit light. The metal wire grid polarizer layer 616 may be made of aluminum, copper, gold, silver, or other metals. The period Pitch of the metal wire grid polarizing layer 616 is preferably 20-500 nm, the period of the metal wire grid polarizing layer 616 refers to the sum of the width of the dielectric layer 615 between two adjacent metal wires 6161 and the width of one metal wire 6161, the height High of the metal wire grid polarizing layer 616 is preferably 100-500 nm, the duty ratio of the metal wire grid polarizing layer 616 is preferably 0.1-0.9, and the metal wire grid polarizing layer 616 has polarization and reflection characteristics, so that the metal wire grid polarizing layer 616 can be well used for replacing a lower polarizer to achieve the same polarization effect. It should be explained that the duty cycle of the metal wire grid polarizing layer 616 is the Width of the metal wire grid polarizing layer 616 divided by the period Pitch of the metal wire grid polarizing layer 616, as shown in fig. 2.

The dielectric layer 615 is a transparent dielectric layer, on one hand, the dielectric layer 615 is used for forming a reflective polarizing layer of the backlight module 61 with the metal wire 6161 in the metal wire grid polarizing layer 616, and on the other hand, the dielectric layer 615 is used for isolating the quantum dot film 612 from being influenced by air and moisture, so that the phenomenon that the quantum dot fluorescent powder in the quantum dot film 612 loses water and oxygen is avoided. The dielectric layer 615 comprises SiO₂、SiO、MgO、Si₃N₄、TiO₂、Ta₂O₅Any one or more of them.

The first substrate 614 is a transparent substrate, and the first substrate 614 is used for supporting the medium layer 615 and the metal wire grid polarizing layer 616.

The protective layer 613 is used to isolate the quantum dot film 612 from air and moisture, so as to avoid the phenomenon that the quantum dot phosphor in the quantum dot film 612 is water-oxygen ineffective.

The quantum dot film 612 comprises red light quantum dots 6121, green light quantum dots 6122, blue light quantum dots 6123, transparent photoresist 6124 and a Black Matrix (Black Matrix)6125, wherein the red light quantum dots 6121 emit red light under excitation of the blue light source 6111 of the LED light source 611, the green light quantum dots 6122 emit green light under excitation of the blue light source 6111 of the LED light source 611, the blue light quantum dots 6123 emit blue light under excitation of the blue light source 6111 of the LED light source 611, the transparent photoresist 6124 can transmit a yellow light source 6112 of the LED light source 611, and the Black Matrix 6125 is arranged between two adjacent quantum dots with different colors and used for isolating the adjacent quantum dots and avoiding the phenomenon that light of different colors of the adjacent quantum dots is mixed with color to affect the definition of the liquid crystal display device.

The LED light source 611 is a two-color LED chip, and includes a blue light source 6111 and a yellow light source 6112, as shown in fig. 3.

The blue light emitted by the blue light source 6111 in the LED light source 611 excites the red light quantum dot 6121, the green light quantum dot 6122 and the blue light quantum dot 6123 in the quantum dot film 612 to emit red light, green light and blue light respectively, the yellow light emitted by the yellow light source 6112 in the LED light source 611 is transmitted through the transparent photoresist 6124 in the quantum dot film 612, and finally, an RGBY four-color backlight source can be formed. Light rays in the quantum dot thin film 612 include TM polarized light with a vibration direction perpendicular to the metal line 6161 and TE polarized light with a polarization direction parallel to the metal line 6161. TM polarized light with a polarization direction perpendicular to the metal lines 6161 is transmitted through the metal wire grid polarizing layer 616, and TE polarized light with a polarization direction parallel to the metal lines 6161 is reflected by the metal lines 6161. When the TE polarized light reflected by the metal wire 6161 passes through the quantum dot thin film 612, the quantum dots are excited to emit light, so that the light emitting efficiency of the quantum dot thin film 612 is improved, as shown in fig. 3.

In this embodiment, since the metal wire grid polarizing layer 616 is a reflective polarizer, about 50% of light penetrates through the metal wire grid polarizing layer, 50% of light reflects, and has a single polarization state, the metal wire grid polarizing layer can be used as a polarizer, and the reflective property of the metal wire grid polarizing layer is utilized to continuously excite the quantum dot thin film 612 to emit light, so as to improve the light emitting efficiency of the backlight module;

in the embodiment, a double-color LED chip is used as a light source of the backlight module, and the double-color LED chip integrates a blue light source and a yellow light source, so that the light-emitting efficiency is high, the area is small, and the cost is low.

Example two

Referring to fig. 4, fig. 4 is a schematic structural diagram of a liquid crystal display device according to an embodiment of the invention. The present embodiment describes the liquid crystal display device in detail on the basis of the above-described embodiments. The display device includes a backlight module 61, a first electrode 62, a liquid crystal molecule layer 63, a second electrode 64, a second substrate 65, and a polarizer 66, wherein the structure of the backlight module 61 is described in the first embodiment, and details are not repeated herein.

The backlight module of the embodiment has the characteristic of high color gamut and has larger brightness, so that the display color gamut and the brightness of the display device can be improved;

the liquid crystal display device of the embodiment provides four-color light sources through the direct type backlight module, has larger brightness, and can further improve the display color gamut and the brightness of the display device;

the liquid crystal display device of the embodiment omits the use of a color film group, greatly reduces the thickness of the liquid crystal display device, and has the advantages that the light transmittance of the color film group is only about 30%, so that the liquid crystal display device of the embodiment can improve the light emitting efficiency and reduce the power consumption.

EXAMPLE III

Referring to fig. 5, fig. 5 is a schematic structural diagram of a bicolor LED chip according to an embodiment of the present invention, where the LED chip 10 includes: the LED comprises a conductive substrate 11, a reflective layer 12, a blue light epitaxial layer 13, a yellow light epitaxial layer 14, an isolation layer 15, an electrode 16 and a passivation layer 17; wherein,

the light reflecting layer 12 is arranged on the conductive substrate 11;

the blue light epitaxial layer 13, the yellow light epitaxial layer 14 and the isolation layer 15 are all arranged on the reflective layer 12, and the isolation layer 15 is located between the blue light epitaxial layer 13 and the yellow light epitaxial layer 14;

the electrodes 16 are respectively arranged on the blue light epitaxial layer 13 and the yellow light epitaxial layer 14;

the passivation layer 17 covers the blue light epitaxial layer 13, the yellow light epitaxial layer 14 and the isolation layer 15.

The conductive substrate 11 should be made of a material with high conductivity. Optionally, the conductive substrate 11 is a conductive Si sheet, an aluminum sheet, or a copper sheet. The conductive Si wafer should be a heavily doped silicon wafer to improve the conductivity. Further, the thickness of the conductive substrate 11 is 500 to 2500 nm.

The reflective layer 12 should be made of a material with good reflectivity. Optionally, the light reflecting layer 12 is made of Ni, Pb, Ni/Pb alloy or Al. Further, the thickness of the light reflecting layer 12 is 300nm to 1500 nm.

Further, please refer to fig. 6, fig. 6 is a schematic structural diagram of a blue light epitaxial layer according to an embodiment of the present invention, where the blue light epitaxial layer forms a blue light LED structure as a blue light source of an LED light source; specifically, the blue epitaxial layer 13 includes: a first GaN buffer layer 131, a first GaN stabilization layer 132, a first n-type GaN layer 133, a first active layer 134, a first AlGaN barrier layer 135, and a first p-type GaN layer 136;

the first p-type GaN layer 136, the first AlGaN blocking layer 135, the first active layer 134, the first n-type GaN layer 133, the first GaN stabilization layer 132, and the first GaN buffer layer 131 are sequentially stacked in a first designated region on the upper surface of the light reflecting layer 12.

The thickness of the first GaN buffer layer 131 is 3000-5000 nm, and is preferably 4000 nm;

the thickness of the first GaN stabilizing layer 132 is 500-1500 nm, preferably 1000 nm;

the first n-type GaN layer 133 has a thickness of 200 to 1000nm, preferably 400nm, and a doping concentration of 1 × 10¹⁸～5×10¹⁹cm^-3Preferably 1X 10¹⁹cm^-3；

Referring to fig. 7, fig. 7 is a schematic structural diagram of a first active layer according to an embodiment of the invention; the first active layer 134 is a first multi-structure formed by a first InGaN quantum well 1341 and a first GaN barrier 1342, and a period of alternately stacking the first InGaN quantum well 1341 and the first GaN barrier 1342 in the first multi-structure is 8 to 30, preferably 20; the thickness of the first InGaN quantum well 1341 is 1.5-3.5 nm, and preferably 2.8 nm; the thickness of the first GaN barrier 1342 is 5 to 10nm, preferably 5 nm; the In content In the first InGaN quantum well 1341 depends on the wavelength of light, and the higher the In content, the longer the wavelength of light is, generally 10 to 20%;

the thickness of the first AlGaN barrier layer 135 is 10-40 nm, preferably 20 nm;

the thickness of the first p-type GaN layer 136 is 100 to 300nm, preferably 200 nm.

Further, on the basis of the above embodiments, please refer to fig. 8, fig. 8 is a schematic structural diagram of a yellow epitaxial layer according to an embodiment of the present invention, where the yellow epitaxial layer forms a yellow LED structure as a yellow light source of an LED light source; specifically, the yellow epitaxial layer 14 includes: a second GaN buffer layer 141, a second GaN stabilization layer 142, a second n-type GaN layer 143, a second active layer 144, a second AlGaN blocking layer 145, and a second p-type GaN layer 146;

the second p-type GaN layer 146, the second AlGaN blocking layer 145, the second active layer 144, the second n-type GaN layer 143, the second GaN stabilization layer 142, and the second GaN buffer layer 141 are sequentially stacked on a second designated region on the upper surface of the light reflecting layer 12.

The thickness of the second GaN buffer layer 141 is 3000-5000 nm, preferably 4000 nm;

the thickness of the second GaN stabilizing layer 142 is 500-1500 nm, preferably 1000 nm;

the second n-type GaN layer 143 has a thickness of 200 to 1000nm, preferably 400nm, and a doping concentration of 1 × 10¹⁸～5×10¹⁹cm^-3Preferably 1X 10¹⁹cm^-3；

Referring to fig. 9, fig. 9 is a schematic structural diagram of a second active layer according to an embodiment of the invention; the second active layer 144 is a second multiple structure formed by a second InGaN quantum well 1441 and a second GaN barrier 1442, and a period of the second InGaN quantum well (1441) and the second GaN barrier (1442) in the second multiple structure in which the layers are alternately stacked is 8 to 30, preferably 20; the thickness of the second InGaN quantum well 1441 is 1.5-3.5 nm, and preferably 2.8 nm; the second GaN barrier 1442 is 5-10 nm, preferably 5 nm; the content of In the second InGaN quantum well 1441 depends on the wavelength of light, and the higher the content, the longer the wavelength of light is, generally 20 to 30%;

the thickness of the second AlGaN barrier layer 145 is 10-40 nm, preferably 20nm, wherein the component proportion of Al is more than 70%;

the thickness of the second p-type GaN layer 146 is 100 to 300nm, preferably 200 nm.

Preferably, the isolation layer 15 and the passivation layer 17 are made of silicon dioxide; wherein, the thickness of the isolation layer 15 is 50-150 nm, and the thickness of the passivation layer 17 is 300-800 nm.

Further, on the basis of the above embodiments, please refer to fig. 10, fig. 10 is a schematic structural diagram of an electrode according to an embodiment of the present invention; the electrode 16 comprises a metal silicide 161 and a metal 162; wherein,

the metal silicide 161 is disposed on the upper surfaces of the blue epitaxial layer 13 and the yellow epitaxial layer 14; specifically, the metal silicide 161 is disposed on the surfaces of the first GaN buffer layer 131 and the second GaN buffer layer 141;

the metal 162 is disposed on the upper surface of the metal silicide 161;

the metal silicide 161 and the metal 162 jointly form an electrode structure, wherein the contact potential barrier of the metal silicide 161 and the semiconductor material is small, ohmic contact is formed, and the contact resistance can be reduced;

in the scheme, the conductive substrate 11 forms an anode commonly connected with the blue LED and the yellow LED; the metal silicide 161 and the metal 162 on the surfaces of the first GaN buffer layer 131 and the second GaN buffer layer 141 form the cathodes of the blue LED and the yellow LED, respectively.

In practical applications, the number and size of the blue LEDs and the yellow LEDs can be determined according to practical requirements.

According to the blue-yellow double-color LED chip provided by the embodiment, the blue light source and the yellow light source are formed on the single chip, so that the using amount of fluorescent powder in later-stage packaging can be reduced, and the color temperature can be adjusted more flexibly; in addition, the conductive substrate is used as the anode of the LED, so that the heat dissipation effect of the LED can be improved.

Example four

Referring to fig. 11a to 11g, fig. 11a to 11g are schematic diagrams illustrating a method for manufacturing a bi-color LED according to an embodiment of the present invention. In this embodiment, a detailed description is given to a manufacturing process of the LED chip structure based on the above embodiments. Specifically, the preparation method comprises the following steps:

step 1, selecting a sapphire substrate 700 with the thickness of 4000nm, as shown in FIG. 11 a.

Step 2, growing a first GaN buffer layer 701 with the thickness of 4000nm on the upper surface of the sapphire substrate 700 at the temperature of 500 ℃; growing a first GaN stabilizing layer 702 with the thickness of 1000nm on the upper surface of the first GaN buffer layer 701 at the temperature of 1000 ℃; growing 400nm thick and 1 × 10 doping concentration on the upper surface of the first GaN stable layer 702 at 1000 deg.C¹⁹cm^-3The first n-type GaN layer 703; growing a first multi-structure formed of a first InGaN quantum well and a first GaN barrier as a first active layer 704 on the upper surface of the first n-type GaN layer 703; wherein the growth temperature of the first InGaN quantum well is 750 ℃, and the thickness of the first InGaN quantum well is 2.8 nm; the growth temperature of the first GaN barrier is 850 ℃, and the thickness of the first GaN barrier is 5 nm; the period of the first InGaN quantum well and the first GaN barrier which are alternately stacked is 20; growing a first AlGaN barrier layer 705 with the thickness of 20nm on the upper surface of the first active layer 704 at the temperature of 400 ℃; at a temperature of 400 ℃, a first p-type GaN layer 706 with a thickness of 200nm is grown on the upper surface of the first AlGaN blocking layer 705, as shown in fig. 11b, wherein the first GaN buffer layer 701, the first GaN stabilization layer 702, the first n-type GaN layer 703, the first active layer 704, the first AlGaN blocking layer 705 and the first p-type GaN layer 706 form a blue LED structure.

Step 3, depositing a first silicon dioxide layer with the thickness of 500nm on the upper surface of the first p-type GaN contact layer 706; selectively etching the first silicon dioxide layer by using a wet etching process to form a first region to be etched on the first silicon dioxide layer; etching the first p-type GaN layer 706, the first p-type AlGaN barrier layer 705, the first active layer 704, the first n-type GaN layer 703, the first GaN stabilizing layer 702 and the first GaN buffer layer 701 in the first region to be etched by using a dry etching process to form a first groove; the first silicon dioxide layer is removed and a second silicon dioxide layer is deposited in the first recess as an isolation layer 800, and the inner region of the silicon dioxide isolation layer is used as the yellow light lamp core groove, as shown in fig. 11 c.

Step 4, growing a second GaN buffer layer 801 with the thickness of 4000nm at the bottom of the yellow lampwick groove at the temperature of 500 ℃; growing a second GaN stabilizing layer 802 with the thickness of 1000nm on the upper surface of the second GaN buffer layer 801 at the temperature of 1000 ℃; growing 400nm thick and 1 × 10 doping concentration on the upper surface of the second GaN stable layer 802 at 1000 deg.C¹⁹cm^-3The second n-type GaN layer 803; growing a second multiple structure formed of a second InGaN quantum well and a second GaN barrier on the upper surface of the second n-type GaN layer 803 as a second active layer 804; wherein the growth temperature of the second InGaN quantum well is 750 ℃ and the thickness is 2.8 nm; the growth temperature of the second GaN barrier is 850 ℃, and the thickness of the second GaN barrier is 5 nm; the period of the second InGaN quantum well and the second GaN barrier in the second multi-structure in alternate stacking is 20; growing a second AlGaN barrier layer 805 with the thickness of 20nm on the upper surface of the second active layer 804 at the temperature of 400 ℃; at a temperature of 850 ℃, a second p-type GaN layer 806 with a thickness of 200nm is grown on the upper surface of the second AlGaN blocking layer 805, as shown in fig. 11d, wherein the second GaN buffer layer 801, the second GaN stabilization layer 802, the second n-type GaN layer 803, the second active layer 804, the second AlGaN blocking layer 805 and the second p-type GaN layer 806 form a yellow LED structure.

Step 5, growing Ni with the thickness of 300nm on the surfaces of the first p-type GaN layer 706 and the second p-type GaN layer 806 by using a sputtering process to serve as a first contact metal layer 901; growing Ni with the thickness of 800nm on the surface of the first contact metal layer 901 to serve as a light reflecting layer 902; selecting a conductive substrate 904, and growing a second contact metal layer 903 with the thickness of 1000nm on the surface of the conductive substrate 904 by using a sputtering process; at the temperature of 400 ℃, the conductive substrate 904 is tightly attached to the surface of the light reflecting layer 902 through the second contact metal layer 903 for 60min to form bonding between the conductive substrate 904 and the light reflecting layer 902, as shown in fig. 11e, wherein the conductive substrate 904 serves as an anode of the common connection of the blue LED and the yellow LED.

Step 6, removing the sapphire substrate 700 by using an excimer laser, and exposing the first GaN701 buffer layer and the second GaN buffer layer 801; as shown in fig. 11 f.

Step 7, depositing silicon dioxide with the thickness of 500nm on the lower surfaces of the first GaN buffer layer 701 and the second GaN buffer layer 801 to be used as a passivation layer 905; selectively etching the passivation layer 905 by using a photolithography process, and forming electrode holes on the lower surfaces of the first GaN buffer layer 701 and the second GaN buffer layer 801; depositing Ni in the electrode hole, and annealing the whole material to form metal silicide on the surfaces of the first GaN buffer layer 701 and the second GaN buffer layer 801; ni is deposited on the metal silicide as the cathode 906 for the blue and yellow LEDs as shown in fig. 11 g.

In the embodiment, the preparation process of the LED chip is realized by adopting the process steps and the process parameters, so that the process flow is greatly simplified, and the preparation cost is reduced.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims

1. A backlight module (61) comprises an LED light source (611), a quantum dot film (612), a dielectric layer (615) and a metal wire grid polarizing layer (616); wherein,

the quantum dot thin film (612) is disposed on the LED light source (611);

the dielectric layer (615) is arranged on the quantum dot thin film (612);

the metallic wire grid polarizing layer (616) is disposed on the dielectric layer (615).

2. The backlight module (61) according to claim 1, further comprising a protective layer (613) and a first substrate (614); wherein,

the protective layer (613) is disposed on the quantum dot thin film (612);

the first substrate (614) is disposed between the protective layer (613) and the dielectric layer (615).

3. The backlight module (61) according to claim 1, wherein the metal wire grid polarizing layer (616) comprises a plurality of metal wires (6161); the metal lines (6161) are arranged on the dielectric layer (615) at intervals.

4. The backlight module (61) according to claim 1, wherein the dielectric layer (615) is a transparent dielectric layer comprising SiO₂、SiO、MgO、Si₃N₄、TiO₂、Ta₂O₅Any one or more of them.

5. The backlight module (61) according to claim 1, wherein the first substrate (614) is a transparent substrate for supporting the dielectric layer (615) and the wire grid polarizer layer (616).

6. The backlight module (61) according to claim 1, wherein the quantum dot film (612) comprises red quantum dots (6121), green quantum dots (6122), blue quantum dots (6123) and transparent photoresist (6124).

7. The backlight module (61) according to claim 6, wherein the quantum dot film (612) further comprises a black matrix (6125).

8. The backlight module (61) according to claim 1, wherein the LED light source (611) is a bi-color LED chip.

9. The backlight module (61) according to claim 8, wherein the bi-color LED chip comprises a blue light source and a yellow light source.

10. A liquid crystal display device comprising a first electrode (62), a liquid crystal molecular layer (63), a second electrode (64), a second substrate (65) and a polarizer (66), characterized by further comprising a backlight module (61) according to any one of claims 1 to 9.