Ligand-modified quantum dot materials, methods of fabricating liquid crystal display panels and liquid crystal display panels

Abstract

The present application provides a ligand-modified quantum dot material, a method of fabricating a liquid crystal display panel, and a liquid crystal display panel. The ligand-modified quantum dot material of the present application can occur a polymerization with the ligand-modified quantum dot material under ultraviolet irradiation to form a polymer, while the polymer deposits on a substrate to form a polymer film, which can replace the PI alignment film, so that an alignment process of liquid crystal is simplified, and a cost is economized; simultaneously, display quality of a liquid crystal display panel can be improved by the quantum dots anchored in the polymer film. The method of fabricating the liquid crystal display panel of the present application eliminates the fabricating process of the PI alignment film, the method has simple process and low cost, and a liquid crystal display panel obtained thereby has better display quality. The liquid crystal display panel of the present application utilizes the polymer film, which is obtained by polymerizing the ligand-modified quantum dot material and a polymerizable monomer, to replace the PI alignment film, so as to greatly enhance quality of the panel, and to have a low fabricating cost.

Claims

1. A ligand-modified quantum dot material, comprising quantum dots and a ligand modifier; wherein a structural formula of the ligand modifier is A-B-R, and the ligand modifier is adsorbed onto surface of the quantum dots through group A; wherein A represents SH, NH.sub.2, NH, or COOH; B represents ##STR00033## Sp represents group (CH.sub.2).sub.n, or the group (CH.sub.2).sub.n having one CH.sub.2 substituted with O, S, CO, COO, OCO, OCOO, OCH.sub.2, CH.sub.2O, CHCH, CFCF, CC, CHCHCOO, or OCOCHCH, wherein n is an integer from 1 to 8; B represents ##STR00034## wherein ##STR00035## is phenyl, a group obtained by H atom of phenyl substituted with F, Cl, Br, I, CN, NO.sub.2, or C(O)H, or cycloalkyl; R represents alkyl of straight chain or branched chain having from 5 to 20 C atoms, a first group obtained by a CH.sub.2 in the alkyl substituted with phenyl, cycloalkyl, CONH, COO, OCO, S, CO, or CHCH, a second group obtained by an H atom in the alkyl substituted with F or Cl atom, or a third group obtained by an H atom in the first group substituted with F or Cl atom; L represents a polymerizable group connecting to group B, and comprises any one, any two, or three of following three groups: ##STR00036##

2. The ligand-modified quantum dot material according to claim 1, wherein the ligand modifier comprises one or more than one of following compounds: ##STR00037##

3. A method of fabricating a liquid crystal display panel, comprising following steps: step 1, providing an upper substrate, a lower substrate, and a liquid crystal material; the upper substrate comprising a first substrate, and a first electrode disposed on the first substrate; the lower substrate comprising a second substrate, and a second electrode disposed on the second substrate; the liquid crystal material comprising liquid crystal molecules, a ligand-modified quantum dot material, and a polymerizable monomer; the ligand-modified quantum dot material comprising quantum dots and a ligand modifier; wherein a structural formula of the ligand modifier is A-B-R, and the ligand modifier is adsorbed onto surface of the quantum dots through group A; wherein A refers SH, NH.sub.2, NH, or COOH; B represents ##STR00038## Sp represents group (CH.sub.2).sub.n, or the group (CH.sub.2).sub.n having one CH.sub.2 substituted with O, S, CO, COO, OCO, OCOO, OCH.sub.2, CH.sub.2O, CHCH, CFCF, CC, CHCHCOO, or OCOCHCH, wherein n is an integer from 1 to 8; B represents ##STR00039## wherein ##STR00040## is phenyl, a group obtained by H atom of phenyl substituted with F, Cl, Br, I, CN, NO.sub.2, or C(O)H, or cycloalkyl; R represents alkyl of straight chain or branched chain having from 5 to 20 C atoms, a first group obtained by a CH.sub.2 in the alkyl substituted with phenyl, cycloalkyl, CONH, COO, OCO, S, CO, or CHCH, a second group obtained by an H atom in the alkyl substituted with F or Cl atom, or a third group obtained by an H atom in the first group substituted with F or Cl atom; L represents a polymerizable group connecting to group B, and comprises any one, any two, or three of following three groups: ##STR00041## step 2, dripping the liquid crystal material on the upper substrate or the lower substrate, coating a sealant on a peripheral position of the upper substrate or the lower substrate, then assembling and laminating the upper substrate and the lower substrate, and curing the sealant; wherein the ligand-modified quantum dot material deposits on the upper substrate and the lower substrate, and the ligand modified quantum dot material to guide the liquid crystal molecules perpendicular to the upper substrate and the lower substrate through group B-R on the ligand modifier; step 3, applying a voltage to both sides of the liquid crystal material through the first electrode and the second electrode, to allow the liquid crystal molecules occurring deflection and arranging along a direction inclined to the upper substrate and the lower substrate; step 4, irradiating ultraviolet to the liquid crystal material under the voltage from either side of the upper substrate or the lower substrate, to allow the ligand-modified quantum dot material polymerizing with the polymerizable monomer to form a first polymer film, a second polymer film, and to deplete the ligand-modified quantum material and polymerizable monomer in the liquid crystal material to form a liquid crystal layer; wherein the first polymer film is disposed between the upper substrate and the liquid crystal layer, and the second polymer film is disposed between the lower substrate and the liquid crystal layer, and the polymer films have polymer projections to maintain the inclined direction by steric hindrance after the voltage being removed; constituting a liquid crystal layer by the liquid crystal material in which the ligand-modified quantum dot material and the polymerizable monomers are removed.

4. The method of fabricating the liquid crystal display panel according to claim 3, wherein the ligand modifier comprises one or more than one of following compounds: ##STR00042##

5. The method of fabricating the liquid crystal display panel according to claim 3, wherein, in the liquid crystal material, a mass percentage of the liquid crystal molecules is from 93.0% to 99.4%, a mass percentage of the ligand-modified quantum dot material is from 0.5% to 5.0%, a mass percentage of the polymerizable monomer is from 0.01% to 2.0%.

6. The method of fabricating the liquid crystal display panel according to claim 3, wherein the voltage applied to the both sides of the liquid crystal material is from 13 to 25V; and an illumination intensity of the ultraviolet is from 85 to 100 mW/cm.sup.2, an irradiation time is from 20 to 30 min.

7. The method of fabricating the liquid crystal display panel according to claim 3, wherein thicknesses of the first polymer film and the second polymer film are from 100 to 1200 .

8. A liquid crystal display panel, comprising: oppositely disposed an upper substrate and a lower substrate, a liquid crystal layer disposed between the upper substrate and the lower substrate, a first polymer film disposed between the upper substrate and the liquid crystal layer, and a second polymer film disposed between the lower substrate and the liquid crystal layer; wherein the upper substrate comprises a first substrate and a first electrode disposed on the first substrate; the lower substrate comprises a second substrate and a second electrode disposed on the second substrate; the liquid crystal layer comprises liquid crystal molecules; both the first polymer film and the second polymer film are formed by polymerizing the polymerizable monomer and the ligand-modified quantum dot material, and surfaces of both the first polymer film and the second polymer film have polymer projections, so as to allow the liquid crystal molecules near the first polymer film and the second polymer film arrange along a direction inclined to the upper substrate and the lower substrate; the ligand-modified quantum dot material comprises quantum dots and a ligand modifier; wherein a structural formula of the ligand modifier is A-B-R, and the ligand modifier is adsorbed onto surface of the quantum dots through group A; wherein A represents SH, NH.sub.2, NH, or COOH; B represents ##STR00043## Sp represents group (CH.sub.2).sub.n, or the group (CH.sub.2).sub.n having one CH.sub.2 substituted with O, S, CO, COO, OCO, OCOO, OCH.sub.2, CH.sub.2O, CHCH, CFCF, CC, CHCHCOO, or OCOCHCH, wherein n is an integer from 1 to 8; B represents ##STR00044## wherein ##STR00045## is phenyl, a group obtained by H atom of phenyl substituted with F, Cl, Br, I, CN, NO.sub.2, or C(O)H, or cycloalkyl; R represents alkyl of straight chain or branched chain having from 5 to 20 C atoms, a first group obtained by a CH.sub.2 in the alkyl substituted with phenyl, cycloalkyl, CONH, COO, OCO, S, CO, or CHCH, a second group obtained by an H atom in the alkyl substituted with F or Cl atom, or a third group obtained by an H atom in the first group substituted with F or Cl atom; L represents a polymerizable group connecting to group B, and comprises any one, any two, or three of following three groups: ##STR00046##

9. The liquid crystal display panel according to claim 8, wherein the ligand modifier comprises one or more than one of following compounds: ##STR00047##

10. The liquid crystal display panel according to claim 8, wherein thicknesses of the first polymer film and the second polymer film are from 100 to 1200 .

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The technical features and other advantages of the present application will become more readily apparent to those ordinarily skilled in the art, by referring the following detailed description of embodiments of the present application in conjunction with the accompanying drawings.

(2) In the accompanying drawings,

(3) FIG. 1 is a figure schematically illustrating a structure of a ligand-modified quantum dot material of the present application;

(4) FIG. 2 is a flow chart schematically illustrating a method of fabricating a liquid crystal display panel of the present application;

(5) FIG. 3 is a figure schematically illustrating step 1-2 of the method of fabricating the liquid crystal display panel of the present application;

(6) FIG. 4 is a figure schematically illustrating step 3 of the method of fabricating the liquid crystal display panel of the present application;

(7) FIG. 5 is a figure schematically illustrating step 4 of the method of fabricating the liquid crystal display panel of the present application;

(8) FIG. 6 is a figure schematically illustrating a structure of a liquid crystal display panel of the present application; and

(9) FIG. 7 is a scanning electron microscope picture schematically illustrating surface topographies of a first polymer film and a second polymer film in the liquid crystal display panel shown in FIG. 6.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(10) In order to further clarify the technical means adopted in the present application and the effects thereof, the preferable embodiments of the present application and the accompanying drawings thereof will be more specifically described as follows.

(11) Please refer to FIG. 1, the present application provides a ligand-modified quantum dot material, including quantum dots (QDs) and a ligand modifier adsorbing surfaces of the quantum dots; a structural formula of the ligand modifier being A-B-R, the ligand modifier adsorbing the surface of the quantum dots through group A;

(12) wherein A refers SH, NH.sub.2, NH, or COOH;

(13) B refers

(14) ##STR00016##

(15) Sp refers group (CH.sub.2).sub.n, or a group obtained by a CH.sub.2 in the group (CH.sub.2).sub.n substituted with O, S, CO, COO, OCO, OCOO, OCH.sub.2, CH.sub.2O, CHCH, CFCF, CC, CHCHCOO, or OCOCHCH, wherein n is an integer 18;

(16) B refers

(17) ##STR00017##
wherein

(18) ##STR00018##
is phenyl, a group obtained by H atom of phenyl substituted with F, Cl, Br, I, CN, NO.sub.2, or C(O)H, or cycloalkyl;

(19) R refers alkyl of straight chain or branched chain having 520 C atoms, a first group obtained by a CH.sub.2 in the alkyl substituted with phenyl, cycloalkyl, CONH, COO, OCO, S, CO, or CHCH, a second group obtained by an H atom in the alkyl substituted with F or Cl atom, or a third group obtained by an H atom in the first group substituted with F or Cl atom;

(20) L refers a polymerizable group connecting to group B, and includes any one, an two, or any three of following three groups:

(21) ##STR00019##

(22) Specifically, the ligand-modified quantum dot material 32 includes a polymerizable group L, so that the ligand-modified quantum dot material 32 can occur a reaction with polymerizable monomers in the liquid crystal material, to form a polymer film, so that the quantum dots are anchored in the polymer film, to solve the problem that the quantum dot material is easily precipitated in the liquid crystal.

(23) Specifically, the ligand modifier includes one or more than one of following compounds:

(24) ##STR00020##

(25) Specifically, the quantum dots are one of CdX, PbX, ZnX, HgX, GaX, and InX, or a shell structure formed by a combination of more than one of CdX, PbX, ZnX, HgX, GaX, and InX, wherein X is S, Se, or Te. Specifically, a size of the quantum dots is 1-30 nm.

(26) Please refer to FIG. 2, the present application further provides a method of fabricating a liquid crystal display panel, including following steps.

(27) Step 1, please refer to FIG. 3, providing an upper substrate 1, a lower substrate 2, and a liquid crystal material.

(28) The upper substrate 1 includes a first substrate 11, and a first electrode 12 is disposed on the first substrate 11; the lower substrate 2 includes a second substrate 21, and a second electrode 22 is disposed on the second substrate 21.

(29) The liquid crystal material includes liquid crystal molecules 31, a ligand-modified quantum dot material 32, and a polymerizable monomer (RM) 33.

(30) The ligand-modified quantum dot material 32 includes quantum dots (QDs), and a ligand modifier adsorbing surfaces of the quantum dots; a structural formula of the ligand modifier is A-B-R, the ligand modifier adsorbs the surfaces of the quantum dots through group A;

(31) wherein A refers SH, NH.sub.2, NH, or COOH;

(32) B refers

(33) ##STR00021##

(34) Sp refers group (CH.sub.2).sub.n, or a group obtained by a CH.sub.2 in the group (CH.sub.2).sub.n substituted with O, S, CO, COO, OCO, OCOO, OCH.sub.2, CH.sub.2O, CHCH, CFCF, CC, CHCHCOO, or OCOCHCH, wherein n is an integer 18;

(35) B refers

(36) ##STR00022##
wherein

(37) ##STR00023##
is phenyl, a group obtained by H atom of phenyl substituted with F, Cl, Br, I, CN, NO.sub.2, or C(O)H, or cycloalkyl;

(38) R refers alkyl of straight chain or branched chain having 520 C atoms, a first group obtained by a CH.sub.2 in the alkyl substituted with phenyl, cycloalkyl, CONH, COO, OCO, S, CO, or CHCH, a second group obtained by an H atom in the alkyl substituted with F or Cl atom, or a third group obtained by an H atom in the first group substituted with F or Cl atom;

(39) L refers a polymerizable group connecting to group B, and includes any one, any two, or any three of following three groups:

(40) ##STR00024##

(41) Specifically, the ligand modifier includes one or more than one of following compounds:

(42) ##STR00025##

(43) Specifically, the quantum dots are one of CdX, PbX, ZnX, HgX, GaX, and InX, or a shell structure formed by a combination of more than one of CdX, PbX, ZnX, HgX, GaX, and InX, wherein X is S, Se, or Te. Specifically, a size of the quantum dots is 1-30 nm.

(44) Specifically, in the liquid crystal material, a mass percentage of the liquid crystal molecules 31 is 93.0%99.4%, a mass percentage of the ligand-modified quantum dot material 32 is 0.5%5.0%, a mass percentage of the polymerizable monomer 33 is 0.01%2.0%.

(45) Specifically, the polymerizable monomer 33 includes one or a combination of more than one of acrylates, acrylate derivatives, methacrylates, methacrylate derivatives, styrene, styrene derivatives, and epoxy resin; wherein the epoxy resin can be fatty amine base epoxy resins.

(46) Preferably, the liquid crystal material further includes a photo initiator, and a mass percentage of the photo initiator is 0.14%0.5%.

(47) Specifically, the photo initiator includes one or a combination of more than one of azobisisobutyronitrile, dialkyl peroxide base compounds, diacyl peroxide base compounds, and lipid peroxide base compound.

(48) Specifically, the liquid crystal molecules 31 include one or more than one of following compounds:

(49) ##STR00026##

(50) Specifically, the upper substrate 1 and the lower substrate respectively are a TFT substrate and a CF substrate; the first electrode 12 and the second electrode respectively are a pixel electrode and a common electrode.

(51) Step 2, please refer to FIG. 3, dripping a liquid crystal material on the upper substrate 1 or the lower substrate 2, coating a sealant 4 on a peripheral position of the upper substrate 1 or the lower substrate 2, then assembling and laminating the upper substrate 1 and the lower substrate 2, and curing the sealant 4.

(52) Due the ligand-modified quantum dot material 32 in the liquid crystal material is hard to be soluble in liquid crystal molecules 31, the ligand-modified quantum dot material 32 thus deposits on the upper substrate 1 and the lower substrate 2, and the ligand-modified quantum dot material 32 guides the liquid crystal molecules 31 arranging perpendicular to the upper substrate 1 and the lower substrate 2 through middle and tail groups B-R on the ligand modifier.

(53) Preferably, in step 2, after the sealant 4 is coated on the peripheral position of the upper substrate 1 or the lower substrate 2, an electric conductive adhesive (not shown) is coated on a periphery of the sealant 4.

(54) Preferably, in step 2, the upper substrate 1 and the substrate 2 are assembled and laminated in a vacuum environment.

(55) Specifically, in step 2, curing the sealant 4 is utilized a method of heating or ultraviolet (UV) irradiation.

(56) Step 3, as shown in FIG. 4, applying a voltage to both sides of the liquid crystal material through the first electrode 11 and the second electrode 21, to allow the liquid crystal molecules 31 occurring deflection and arranging along a direction inclined to the upper substrate 1 and the lower substrate 2.

(57) Specifically, in step 3, the voltage applied to the both sides of the liquid crystal material is 1325V.

(58) Step 4, as shown in FIG. 5, under the condition of applying the voltage to the liquid crystal material, irradiating ultraviolet to the liquid crystal material from a side of the upper substrate 1 or the lower substrate 2, to allow the ligand-modified quantum dot material 32 in the liquid crystal material occurring a polymerization with the polymerizable monomer 33 through the ligand modifier on the ligand-modified quantum dot material 32 to form a polymer, wherein the polymer deposits on the upper substrate 1 toward a side of the liquid crystal material to form a first polymer film 41, and simultaneously deposits on the lower substrate 2 toward a side of the liquid crystal material to form a second polymer film 42, surfaces of both the first polymer film 41 and the second polymer film 42 have polymer projections, so as to allow the liquid crystal molecules around the first polymer film 41 and the second polymer film 42 maintain the inclined direction thereof in a steric hindrance manner, after the voltage is removed, and an alignment of the liquid crystal molecules 31 is achieved.

(59) As shown in FIG. 6, the liquid crystal material in which the ligand-modified quantum dot material 32 and the polymerizable monomers 33 are removed constitutes a liquid crystal layer 3, the fabrication of the liquid crystal display panel is completed.

(60) Specifically, in the irradiating ultraviolet of step 4, an illumination intensity of the ultraviolet is 85100 mW/cm.sup.2, an irradiation time is 2030 min.

(61) Preferably, in step 4, ultraviolet irradiates the liquid crystal material from the side of the upper substrate (i.e. TFT substrate). Because the TFT substrate has a higher transmittance compared to the CF substrate, UV transmittance can be increased, and an effect of UV irradiation can be enhanced.

(62) Specifically, thicknesses of the first polymer film 41 and the second polymer film 42 are 1001200 . FIG. 7 is a scanning electron microscope picture schematically illustrating surface topographies of a first polymer film 41 and a second polymer film 42, as shown in FIG. 7, both the first polymer film 41 and the second polymer film have rough surfaces.

(63) Please refer to FIG. 6, the present application further provides a liquid crystal display panel, including: oppositely disposed an upper substrate 1 and a lower substrate 2, a liquid crystal layer 3 disposed between the upper substrate 1 and the lower substrate 2, a first polymer film 41 disposed on the upper substrate 1 toward a side surface of the liquid crystal layer 3, and a second polymer film 42 disposed on the lower substrate 2 toward a side surface of the liquid crystal layer 3; wherein the upper substrate 1 includes a first substrate 11 and a first electrode 12 disposed on the first substrate 11; the lower substrate 2 includes a second substrate 21 and a second electrode 22 disposed on the second substrate 21.

(64) The liquid crystal layer 3 includes liquid crystal molecules 31.

(65) Both the first polymer film 41 and the second polymer film 42 are formed by polymerizing the polymerizable monomer 33 and the ligand-modified quantum dot material 32, and surfaces of both the first polymer film 41 and the second polymer film 42 have polymer projections, so as to allow the liquid crystal molecules 31 have a pre-inclination angle; that is, the liquid crystal molecules 31 in the liquid crystal layer 3 near the first polymer film 41 and the second polymer film 42 arrange along a direction inclined to the upper substrate 1 and the lower substrate 2.

(66) The ligand-modified quantum dot material 32 includes quantum dots (QDs), and a ligand modifier adsorbs surfaces of the quantum dots; a structural formula of the ligand modifier is A-B-R, the ligand modifier adsorbs the surface of the quantum dots through group A;

(67) wherein A refers SH, NH.sub.2, NH, or COOH;

(68) B refers

(69) ##STR00027##

(70) Sp refers group (CH.sub.2).sub.n, or a group obtained by a CH.sub.2 in the group (CH.sub.2).sub.n substituted with O, S, CO, COO, OCO, OCOO, OCH.sub.2, CH.sub.2O, CHCH, CFCF, CC, CHCHCOO, or OCOCHCH, wherein n is an integer 18;

(71) B refers

(72) ##STR00028##
wherein

(73) ##STR00029##
is phenyl, a group obtained by H atom of phenyl substituted with F, Cl, Br, I, CN, NO.sub.2, or C(O)H, or cycloalkyl;

(74) R refers alkyl of straight chain or branched chain having 520 C atoms, a first group obtained by a CH.sub.2 in the alkyl substituted with phenyl, cycloalkyl, CONH, COO, OCO, S, CO, or CHCH, a second group obtained by an H atom in the alkyl substituted with F or Cl atom, or a third group obtained by an H atom in the first group substituted with F or Cl atom;

(75) L refers a polymerizable group connecting to group B, and includes any one, any two, or any three of following three groups:

(76) ##STR00030##

(77) Specifically, the ligand modifier includes one or more than one of following compounds:

(78) ##STR00031##

(79) Specifically, the quantum dots are one of CdX, PbX, ZnX, HgX, GaX, and InX, or a shell structure formed by a combination of more than one of CdX, PbX, ZnX, HgX, GaX, and InX, wherein X is S, Se, or Te. Specifically, a size of the quantum dots is 1-30 nm.

(80) Specifically, thicknesses of the first polymer film 41 and the second polymer film 42 are 1001200 . FIG. 7 is a scanning electron microscope picture schematically illustrating surface topographies of a first polymer film 41 and a second polymer film 42, as shown in FIG. 7, both the first polymer film 41 and the second polymer film have rough surfaces.

(81) Specifically, the polymerizable monomer 33 includes one or a combination of more than one of acrylates, acrylate derivatives, methacrylates, methacrylate derivatives, styrene, styrene derivatives, and epoxy resin; wherein the epoxy resin can be fatty amine base epoxy resins.

(82) Specifically, the liquid crystal molecules 31 include one or more than one of following compounds:

(83) ##STR00032##

(84) Specifically, the liquid crystal display panel further includes a sealant 4 disposed between the upper substrate 1 and the lower substrate 2 and located at periphery of the liquid crystal layer 3. Preferably, the liquid crystal display panel further includes an electric conductive adhesive (not shown) is located at a periphery of the sealant 4.

(85) Specifically, the upper substrate 1 and the lower substrate respectively are a TFT substrate and a CF substrate; the first electrode 12 and the second electrode respectively are a pixel electrode and a common electrode.

(86) In summary, the present application provides a ligand-modified quantum dot material, a method of fabricating a liquid crystal display panel, and a liquid crystal display panel. The ligand-modified quantum dot material of the present application can occur a polymerization with the ligand-modified quantum dot material under ultraviolet irradiation to form a polymer, while the polymer deposits on a substrate to form a polymer film, which can replace the PI alignment film, so that an alignment process of liquid crystal is simplified, and a cost is economized; simultaneously, display quality of a liquid crystal display panel can be improved by the quantum dots embedded in the polymer film, and the problems that the quantum dots in the liquid crystal material has uneven diffusion, easily precipitating, and low luminescence efficiency can be solved. The method of fabricating the liquid crystal display panel of the present application eliminates the fabricating process of the PI alignment film, the method has simple process and low cost, and a liquid crystal display panel obtained thereby has better display quality. The liquid crystal display panel of the present application utilizes the polymer film, which is obtained by polymerizing the ligand-modified quantum dot material and a polymerizable monomer, to replace the PI alignment film; that not only meets the aspect of liquid crystal alignment, but also prevent impurities in the CF substrate to diffuse into the liquid crystal layer, so as to greatly enhance quality of the panel, and to have a low fabricating cost. By introducing the quantum dots material into the polymer film, light source utilization can be increased, color light of higher purity can be obtained, and high color gamut and low power consumption can be achieved.

(87) The above description, for an ordinarily skilled in the art, he can complete various similar modifications and arrangements according to the technical programs and ideas of the present application, and the scope of the appended claims of the present application should encompass all such modifications and arrangements.