TWI677996B - Quantum structure light emitting module - Google Patents

Abstract

A quantum structure light emitting module includes a quantum structure film and a light emitting unit. The quantum structure thin film includes a first substrate and a second substrate spaced apart, and an excitation layer located between the first substrate and the second substrate and including a plurality of quantum structures. The light-emitting unit includes a first light-emitting element for emitting blue light and capable of exciting the quantum structures to generate green light, and a second light-emitting element for emitting red light. The red light, blue light, and green light are mixed to form white light and emitted from the second substrate. The invention can increase the intensity of the red light component, thereby improving the width of the color gamut of the display and saturating the colors. Because the present invention only generates green light through the excitation of these quantum structures through light, red light is not generated in this way, so the amount of quantum structure can be reduced to reduce the use of cadmium materials.

Description

Quantum structure light emitting module

The invention relates to a light-emitting module, in particular to a light-emitting module containing a quantum structure film capable of being excited by light to emit light.

One of the known methods for generating white light from light emitting diode (LED) light emitting devices is to use a film containing quantum dots as the light emitting layer of the light emitting diode. The quantum dots are irradiated by an excitation light source, and are obtained by mixing light after emitting secondary light having a wavelength different from that of the excitation light source. For example, a blue LED can be used as an excitation light source, and quantum dot materials with different particle sizes can be excited to generate red and green light. Red, green, and blue light can be mixed to form white light.

The above-mentioned light-emitting device including a quantum dot optical film can be applied to a backlight module of a display. Compared with a conventional backlight module, a backlight module containing a quantum dot optical film can provide a display with richer color levels and chroma. , The color gamut is wide, the color expression is rich and more real, so that the display presents high-quality picture quality with saturated colors and vivid colors.

Among them, cadmium-containing semiconductor materials are common quantum dot materials, such as CdS, CdSe, CdTe, etc., but because cadmium metal is toxic, it is necessary to reduce the amount of cadmium. At present, there are also quantum dot materials using CsPbX ₃ , where X is chlorine, bromine, iodine, or any combination of the above. By adjusting the proportion of chlorine, bromine, and iodine and the size of the quantum dots, the color of the excited light of the quantum dots can be changed. The method is to use blue LEDs to excite CsPbX ₃ quantum dots to obtain red and green light. However, it is found in practice that the red light obtained in this way is insufficient and affects the display color. The color performance is not as good as that of using cadmium-containing quantum dot materials. Display, therefore, while reducing the amount of cadmium, we must also consider how to balance color performance and imaging needs.

Therefore, the object of the present invention is to provide a quantum structure light emitting module capable of reducing the amount of cadmium and improving the display color gamut breadth and color richness.

Therefore, the quantum structure light emitting module of the present invention includes a quantum structure film and a light emitting unit.

The quantum structure film includes a first substrate, a second substrate, and an excitation layer. The first substrate includes an opposite first surface and a light incident surface. The second substrate is spaced apart from the first substrate and includes a second surface facing the first surface and a light emitting surface opposite to the second surface. The excitation layer is located between the first surface of the first substrate and the second surface of the second substrate. The excitation layer includes several quantum structures, and the quantum structures are quantum dots or quantum rods.

The light emitting unit is located on one side of the quantum structure film and includes a first light emitting element for emitting blue light and a second light emitting element for emitting red light. The red light and blue light emitted by the light-emitting unit can pass through the first substrate and enter the excitation layer, and the blue light excites the quantum structures of the excitation layer to emit green light, and the red light, blue light, and green light are mixed by the light. The light emitting surface of the second substrate is emitted.

The effect of the present invention is that the first light-emitting element emits blue light to excite the quantum structures to generate green light, and the second light-emitting element emits red light in combination with the second light-emitting element. The invention can increase the intensity of the red light component, thereby improving the width of the color gamut of the display, making the colors saturated and vivid, and increasing the brightness of the mixed light. Because the present invention only generates green light through light to excite these quantum structures, red light is not generated in this way, so the amount of quantum structure can be reduced, the cadmium material used in the quantum structure can be reduced, or The cadmium material is used, so the present invention has the advantage of reducing the amount of cadmium.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are represented by the same numbers.

Referring to FIG. 1, a first embodiment of a quantum structure light emitting module according to the present invention includes a quantum structure film 10 and a light emitting unit 4.

The quantum structure thin film 10 includes a first substrate 1, a second substrate 2, and an excitation layer 3 stacked on top of each other. The first substrate 1 includes a first surface 11 and a light incident surface 12 opposite to each other. The second substrate 2 is opposite to the first substrate 1 and includes a second surface 21 facing the first surface 11 and a light emitting surface 22 opposite to the second surface 21. The materials of the first substrate 1 and the second substrate 2 may be polyethylene terephthalate (PET), cyclo olefin (co) -polymers (COC), Polyimide (PI), Polyestersulfone (PES), Polyethylene naphthalate (PEN), Polycarbonate (PC), or any of the foregoing materials combination. A water blocking film can be formed on the surfaces of the first substrate 1 and the second substrate 2 to prevent water and gas from entering, thereby preventing water and gas from affecting the excitation layer 3.

The excitation layer 3 is located between the first surface 11 of the first substrate 1 and the second surface 21 of the second substrate 2, and includes a plurality of quantum structures 31, which can be excited by blue light to generate green light. The quantum structure 31 is a quantum dot (Quantum Dot) or a quantum rod (Quantum Rod). When a quantum dot is used, its size is preferably 9 nm to 13 nm. In this range, the quantum dots are generated by being excited. Green light, which can be closer to pure green, can improve the color gamut of the display. The materials of the quantum structures 31 may include CsPbBr ₃ or CH ₃ NH ₃ PbBr _{3. The} above materials are perovskite materials that do not contain cadmium (Cd), and have good applications in quantum dots or quantum rods. In addition, the materials of the quantum structure 31 may also be selected from materials containing Cd, such as CdS, CdSe, or CdTe. The display using the above-mentioned Cd-containing material has a good color formation effect.

When the excitation layer 3 is formed, the quantum structure 31 material is mainly immersed in an oleic acid solution and an oleylamine solution. By controlling the parameters such as the immersion time and the solution concentration, the quantum structure 31 of a desired size can be adjusted, and Oleic acid and oleylamine are mixed stabilizers, so that the quantum structure 31 has good light stability. The quantum structure 31 is then dispersed in a colloidal system. The material of the colloidal system is a resin that can transmit light and has a uniform light effect, and is then applied to the first substrate 1 by a coating method. An adhesive film is formed on the surface 11 or the second surface 21 of the second base material 2, and then depending on whether the materials of the quantum structures 31 are selected for annealing, the excitation layer 3 can be obtained, and the annealing is used to change the quantum structure. 31 level and reduce crystal defects, improve luminous efficiency.

The light-emitting unit 4 faces the light-incident surface 12 of the first substrate 1 and includes a circuit substrate 43 and a plurality of first light-emitting elements 41 and a plurality of second light-emitting elements located on the circuit substrate 43 and spaced alternately. Piece 42. The first light emitting elements 41 are used to emit blue light, such as a blue light emitting diode (LED), and the second light emitting elements 42 are used to emit red light, such as a red light emitting diode. The red LED used in the second light-emitting element 42 of this embodiment contains a phosphor powder of potassium fluorosilicate and tetravalent manganese ions (K ₂ SiF ₆ : Mn ⁴⁺ ), which is a kind of fluoride phosphor powder. It is referred to as KSF phosphor for short, and LEDs containing such phosphor may be referred to as KSF LED for short. The advantages of KSF phosphors are the narrow half-wave width and high energy of the emission spectrum, which can improve the color gamut coverage when used in displays.

When the present invention is used, the blue light emitted by the first light-emitting elements 41 and the red light emitted by the second light-emitting elements 42 can enter the excitation layer 3 from the light incident surface 12 of the first substrate 1 and the blue light The quantum structures 31 that excite the excitation layer 3 emit green light, and incident red light, blue light, and mixed green light are mixed to generate white light, and are emitted from the light emitting surface 22 of the second substrate 2. The center wavelength of the green light emitted by the quantum structures 31 is preferably 520 nm to 540 nm. The invention can be applied to a display as a backlight module and placed on a panel module (not shown) side of the display, and the light emitting surface 22 faces the panel module, so that mixed light can pass through the light emitting surface 22 Shoot at the panel module.

In summary, the first light-emitting element 41 emits blue light to excite the quantum structures 31 to produce green light, and the second light-emitting element 42 can actively emit red light in combination with the second light-emitting element 42 instead of using the light excitation light to generate red light in the past. Light, the invention can increase the intensity of the red light component, thereby improving the breadth of the color gamut, saturating the colors, and increasing the brightness of the mixed light. Therefore, the present invention is applied to a display, which can saturate and enrich the color of the display, close to the colors of real people and objects, and achieve higher-quality color effects. Further, when the second light-emitting element 42 is a KSF LED, the effect of improving the color gamut width and color saturation of the present invention is better. Also, because the present invention only generates green light through the excitation of the quantum structures 31 through light, red light is not generated in this way. Therefore, the present invention is relative to products in which both red and green light are generated by exciting quantum dots. In other words, the present invention can reduce the amount of quantum structure 31. In this way, even if the selected quantum structure 31 contains cadmium, the cadmium material used in the entire quantum structure 31 can be reduced, or a material containing no cadmium can be selected. The invention can indeed reduce the amount of cadmium used.

Referring to FIG. 2, a second embodiment of a quantum structure light emitting module according to the present invention is substantially the same as the structure of the first embodiment, except that the first substrate 1 of this embodiment further includes a plurality of The first microstructure 13 of the light surface 12. The second substrate 2 further includes a plurality of second microstructures 23 located on the light emitting surface 22. The first microstructures 13 and the second microstructures 23 have a light diffusing and homogenizing effect. The materials may be polymethyl methacrylate (acrylic), polyurethane (PU), or silicone. ), Or any combination of the above. The shapes of the first microstructures 13 may be the same or different, and the shapes of the second microstructures 23 may also be the same or different. The shape may be a cone, a semicircle, a regular hexagon, an irregular concave-convex structure, and the like. The first microstructures 13 can refract the light emitted by the light-emitting unit 4 to increase the light path of blue light in the quantum structure film 10, can excite more of these quantum structures 31, and effectively improve green light. Conversion efficiency, producing more green light, applied to the display can achieve wide color gamut, color saturation, vivid effects. In addition, disposing the second microstructures 23 on the second substrate 2 can effectively reduce the total reflection phenomenon caused by the light emitted from the surface of the light emitting surface 22, thereby improving the overall light extraction rate.

The light emitting unit 4 of the first embodiment and the second embodiment directly faces the light incident surface 12 of the first substrate 1 and is a direct-type light-emitting module. When the present invention is implemented, it can also be designed as an edge-light The light emitting module is described in detail in the following embodiments.

Referring to Figs. 3 and 4, a third embodiment of a quantum structure light emitting module according to the present invention has substantially the same structure as the first embodiment, except that the light emitting module of this embodiment is an edge-lit light emitting module. And further includes a light guide plate 5 on the light incident surface 12 side of the first substrate 1. The light guide plate 5 includes a light guide light exit surface 51 facing the light incident surface 12, a light guide reflection surface 52 spaced apart from the light guide light exit surface 51, and a light guide light exit surface 51 and the light guide. The light guide incident surface 53 on the side edge of the reflecting surface 52. The light guide reflection surface 52 has a halftone dot array structure, and further has a function of reflecting light.

The light-emitting units 4 of this embodiment face the light-guiding light-entering surface 53, and the first light-emitting elements 41 and the second light-emitting elements 42 are staggered along the extending direction of the light-guiding light-entering surface 53. The light (blue light and red light) of the light emitting unit 4 enters the light guide plate 5 through the light guide incident surface 53 and is reflected by the light guide reflective surface 52 toward the light guide light exit surface 51, and then the light passes through the light guide After the light incident surface 12 of the first substrate 1 enters the first substrate 1. Therefore, the blue light and the red light of the light-emitting unit 4 can pass through the first substrate 1 as well, and the blue light excites the excitation layer 3 into green light, and finally each color light is mixed into white light and emitted from the light emitting surface 22 of the second substrate 2 Shoot out.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited in this way, any simple equivalent changes and modifications made in accordance with the scope of the patent application and the content of the patent specification of the present invention are still Within the scope of the invention patent.

10‧‧‧ Quantum Structure Film

1‧‧‧ the first substrate

11‧‧‧ the first side

12‧‧‧Into the light surface

13‧‧‧ the first microstructure

2‧‧‧ second substrate

21‧‧‧Second Side

22‧‧‧ light surface

23‧‧‧Second microstructure

3‧‧‧ excitation layer

31‧‧‧ Quantum Structure

4‧‧‧light-emitting unit

41‧‧‧The first luminous part

42‧‧‧Second luminous element

43‧‧‧circuit board

5‧‧‧light guide

51‧‧‧light guide light exit surface

52‧‧‧light guide reflective surface

53‧‧‧light guide light incident surface

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: FIG. 1 is an incomplete cross-sectional schematic diagram illustrating a first embodiment of the quantum structure light emitting module of the present invention; FIG. 2 is an incomplete cross-sectional schematic diagram illustrating a second embodiment of the quantum structure light emitting module of the present invention; FIG. 3 is an incomplete cross-sectional schematic diagram illustrating a third embodiment of the quantum structure light-emitting module of the present invention 4; and FIG. 4 is a schematic plan view illustrating the relative relationship between a light guide plate and a light emitting unit in the third embodiment.

Claims (7)

A quantum structure light-emitting module includes: a quantum structure film including a first substrate including an opposite first surface and a light incident surface; a second substrate opposite to the first substrate, and The second surface includes a second surface facing the first surface, and a light emitting surface opposite to the second surface. An excitation layer is located on the first surface of the first substrate and the second surface of the second substrate. In between, the excitation layer includes several quantum structures, the quantum structures being quantum dots or quantum rods; and a light emitting unit located on one side of the quantum structure thin film, and including a first light emitting element for emitting blue light, and A second light-emitting element for emitting red light; the red and blue light emitted by the light-emitting unit can pass through the first substrate and enter the excitation layer, and the blue light excites the quantum structures of the excitation layer to emit green light, the Red light, blue light and green light are mixed and emitted from the light-emitting surface of the second substrate; wherein the second light-emitting element is a red light-emitting diode containing potassium fluorosilicate phosphor; the quantum Structured material is CsPbBr ₃ or CH ₃ NH ₃ PbBr ₃ . The quantum structure light emitting module according to claim 1, wherein the quantum structures are quantum dots and have a size of 9 nm to 13 nm. The quantum structure light-emitting module according to claim 2, wherein the central wavelength of the green light emitted by the quantum structures upon excitation is 520 nm to 540 nm. The quantum structure light emitting module according to claim 1, wherein the first substrate further includes a plurality of first microstructures formed on the light incident surface. The quantum structure light emitting module according to claim 4, wherein the second substrate further includes a plurality of second microstructures formed on the light emitting surface. The quantum structure light-emitting module according to claim 1 is a direct-type light-emitting module, and the light-emitting unit faces the light incident surface of the first substrate. The quantum structure light-emitting module according to claim 1 is an edge-light-type light-emitting module, and further includes a light guide plate located on the light incident side of the first substrate, and the light guide plate includes a light guide plate facing the light guide plate. A light-guiding light-emitting surface of the light-incident surface, a light-guiding reflection surface opposite to the light-guiding light-emitting surface, and a light-guiding light-incident surface connected to the light-guiding light-emitting surface and a side edge of the light-guiding reflection surface, the light emitting The unit faces the light guide and light incident surface.