Composition

Abstract

The present invention relates to a composition comprising at least one nanometer-sized luminescent material.

Description

Technical Field

[0001] The present invention relates to a composition comprising at least one nano-sized luminescent material and at least one compound represented by the general formula (1) or (2) described below as an additive, and to a formulation comprising the composition. In addition, the present invention relates to the use of the composition in a method for manufacturing an optical medium and the use of the composition in a device, as well as to an optical medium and an optical device. Background Art

[0002] The stability of nanometer-sized luminescent materials, such as quantum dots (QDs), is essential for their use in, for example, electronic, optical or biomedical devices. Stable QDs do not lose their photoluminescence intensity during the processing of device fabrication and device operation, which can expose the QDs to high temperatures, air, moisture and chemicals.

[0003] In particular, poor thermal stability is an obstacle to the practical application of quantum dot-based devices. Various methods are described in the prior art to improve the photo- and / or thermal stability of QDs, including encapsulation in a polymer matrix, cross-linking, increasing shell thickness, etc.

[0004] Another approach to improving QD stability is to combine the QD with a stabilizing additive. This combination can prevent quantum dot particle degradation (e.g., photodegradation or thermal degradation). The additive can be attached to the particle surface and act as a surface-modified ligand. WO 2017 / 048510 A1 relates to derivatives based on phosphine and phosphine oxide as stabilizing additives for nanoparticles. US 9,701,896 B2 relates to a composition comprising quantum dots and an emission stabilizer, such as an aliphatic phosphine oxide or a salt based on an aliphatic phosphate ester / salt.

[0005] However, there is still a need for compounds that can act as stabilizer additives to further improve the overall stability of nanosized light-emitting materials, particularly their resistance to thermal damage. Summary of the invention

[0006] The present invention has been accomplished in view of the problems described above. Therefore, an object of the present invention is to provide a composition comprising a nano-sized luminescent material having improved stability and resistance, particularly stability and resistance to thermal damage, and which can maintain or even increase quantum yield when heated.

[0007] Another object of the present invention is to provide an optical medium and an optical device having improved stability, in particular thermal stability, and high quantum yield (QY).

[0008] The inventors of the present invention have surprisingly found that one or more of the problems described above can be solved by the features defined in the claims.

[0009] Specifically, in order to solve one or more of the problems described above, the present invention provides a composition comprising at least one nano-sized luminescent material and at least one compound represented by the following general formula (1) or (2), consisting essentially of them, or consisting of them:

[0010]

[0011] in

[0012] R 1 , R 2 , R 3 , R 4 , R 5 , R 6 are identically or differently selected from alkyl groups, aryl groups, heteroaryl groups, aralkyl groups, heteroaralkyl groups, alkaryl groups and alkylheteroaryl groups; and Z is P, As or Sb.

[0013] Furthermore, the invention relates to a formulation comprising a composition according to the invention and at least one solvent.

[0014] The invention further provides for the use of a composition according to the invention or of such a formulation in a process for producing an optical medium.

[0015] The present invention further provides the use of a composition according to the invention or of such a formulation in an electronic, optical or biomedical device.

[0016] Furthermore, the present invention relates to an optical medium comprising the composition according to the invention, and to an optical device comprising said optical medium.

[0017] Further advantages of the present invention will become apparent from the following detailed description. DETAILED DESCRIPTION OF THE INVENTION

[0019] The best mode for carrying out the invention is described in detail below.

[0020] As used herein, an asterisk ("*" or "*") is generally used to indicate a connection to an adjacent unit or group, including, for example, a connection to an adjacent repeating or structural unit in the case of a polymer, or a connection to another group, such as a side chain in the case of a monomeric compound.

[0021] ——Compound

[0022] In order to solve the object of the present invention as described above, there is provided a composition according to the present invention, which comprises at least one nano-sized luminescent material and at least one compound represented by the following general formula (1) or (2), consists essentially of them, or consists of them:

[0023]

[0024] in

[0025] R 1 , R 2 , R 3 , R 4 , R 5 , R 6 are identically or differently selected from alkyl groups, aryl groups, heteroaryl groups, aralkyl groups, heteroaralkyl groups, alkaryl groups and alkylheteroaryl groups; and

[0026] Z is P, As or Sb.

[0027] The groups R in the compounds of formula (1) and (2) are 1 , R 2 , R 3 , R 4 , R 5 , R 6 In each case may be substituted as will be defined below.

[0028] The composition according to the present invention may comprise one or more compounds of formula (1) or one or more compounds of formula (2), or the composition may comprise one or more compounds of each of formulas (1) and (2), each in combination with the at least one nanosized luminescent material.

[0029] The inventors of the present invention have surprisingly found that by combining nanosized luminescent materials (e.g. quantum dots) with at least one compound of formula (1) and / or (2) as a stabilizing additive, the overall stability of the nanosized luminescent materials (e.g. quantum dots), and in particular the thermal stability at higher temperatures, can be improved while maintaining or even improving the quantum yield.

[0030] The following definitions apply to chemical groups used as general definitions. They apply only if no more specific definition is given.

[0031] An aryl group in the sense of the present invention is an aromatic group containing 5 to 30 aromatic ring atoms, none of which is a heteroatom. Here, an aryl group is taken to mean a simple aromatic ring, such as benzene, or a fused (condensed) aromatic polycycle, such as naphthalene, phenanthrene or anthracene.

[0032] A fused aromatic polycyclic in the sense of the present application consists of two or more simple aromatic rings fused to each other (fused ring). In addition, aromatic groups in which two or more aryl groups are linked to each other via a single bond are also considered to be aryl groups in the sense of the present invention, for example, groups such as biphenyl and terphenyl.

[0033] A heteroaryl group in the sense of the present invention is an aromatic group containing 5 to 30 aromatic ring atoms, at least one of which is a heteroatom, i.e. a heteroaromatic group. The heteroatom is preferably selected from N, O and S. Here, a heteroaryl group is taken to mean a simple heteroaromatic ring, such as pyridine, pyrimidine or thiophene, or a fused (condensed) heteroaromatic polycycle, such as quinoline or carbazole. A fused heteroaromatic polycycle in the sense of the present application consists of two or more simple heteroaromatic rings fused to each other (condensed).

[0034] Thus, a heteroaryl group is defined as an aryl group as described above, with the difference that it must have at least one heteroatom as one of the aromatic ring atoms. Thus, it differs from an aryl group as defined in the present application which cannot contain any heteroatoms as aromatic ring atoms.

[0035] An aryl or heteroaryl radical, which in each case may be substituted as will be defined hereinafter and which may be attached to the atom Z via any desired position, is taken to mean in particular a radical derived from benzene, naphthalene, anthracene, phenanthrene, pyrene, dihydropyrene, Perylene, fluoranthene, benzanthracene, triphenylene, tetracene, pentacene, benzopyrene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthimidazole, pyridimidazole, pyrazinimidazole, quinoxalinimidazole, oxazole, benzoxazole, naphthimidazole, anthraquinoxazole, phenanthroxithazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine , benzopyrimidine, quinoxaline, pyrazine, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine, benzothiadiazole, biphenyl, terphenyl, quaterphenyl, fluorene and spirobifluorene.

[0036] An alkaryl group in the sense of this invention is understood to mean an aryl group as defined above to which an alkyl group as defined below is bonded.

[0037] An alkylheteroaryl group in the sense of this invention is understood to mean a heteroaryl group as defined above, to which an alkyl group as defined below is bonded.

[0038] For the purposes of the present invention, an alkyl group is taken to mean a saturated, monovalent, straight-chain alkyl group having 1 to 20, 1 to 30 or 1 to 40 C atoms, or a branched or cyclic alkyl group having 3 to 30 or 3 to 40 C atoms, which in each case may also be substituted, as will be defined hereinafter, and is taken to mean in particular the radicals methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl or 2,2,2-trifluoroethyl.

[0039] Furthermore, for the purposes of the present invention, an alkenyl or alkynyl group is taken to mean an unsaturated, monovalent, straight-chain or branched alkenyl or alkynyl group having 2 to 40 C atoms, which in each case may also be substituted, as will be defined hereinafter, and is taken in particular to mean the radicals ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl or octynyl.

[0040] An aralkyl group in the sense of this invention is understood to mean an alkyl group as defined above to which an aryl group as defined above is bonded.

[0041] A heteroaralkyl group in the sense of this invention is understood to mean an alkyl group as defined above to which a heteroaryl group as defined above is bonded.

[0042] Alkoxy radicals having 1 to 20 C atoms, which may also be substituted, as will be defined hereinafter, are preferably taken to mean methoxy, trifluoromethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, sec-pentoxy, 2-methylbutoxy, n-hexyloxy, cyclohexyloxy, n-heptyloxy, cycloheptyloxy, n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy or 2,2,2-trifluoroethoxy.

[0043] Preferably, in the compounds of formula (1) and (2), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 are identically or differently selected from alkyl groups, aryl groups and heteroaryl groups, the alkyl groups being selected from linear alkyl groups having 1 to 30 C atoms, more preferably 1 to 20 C atoms, and branched or cyclic alkyl groups having 3 to 30 C atoms, more preferably 3 to 20 C atoms, the aryl groups being selected from aromatic groups having 5 to 30 aromatic ring atoms, more preferably 5 to 18 aromatic ring atoms, the heteroaryl groups being selected from heteroaromatic groups having 5 to 30 aromatic ring atoms, more preferably 5 to 18 aromatic ring atoms, wherein the linear, branched and cyclic alkyl groups and the aromatic and heteroaromatic groups may in each case be replaced by one or more radicals R 7 Substituted (ie one or more H atoms in the linear, cyclic or branched alkyl group or in the aromatic or heteroaromatic group may be replaced);

[0044] Where R 7 are selected from the group consisting of F, Cl, Br, I, CN, NH2, N(R 8 )2、OH、NHC(O)R 8 , OR 8 , acrylate groups (—OC(O)CHCH2) or methacrylate groups (—OC(O)C(CH3)CH2), linear alkyl groups having 1 to 20 C atoms, branched alkyl groups having 3 to 20 C atoms, aromatic groups having 5 to 30 aromatic ring atoms and heteroaromatic groups having 5 to 30 aromatic ring atoms, wherein one or more H atoms in the linear or branched alkyl group or in the aromatic or heteroaromatic group may be replaced by F, Cl, Br, I and / or CN; and wherein

[0045] R 8 are selected identically or differently from linear alkyl radicals having 1 to 20 C atoms and branched alkyl radicals having 3 to 20 C atoms, wherein one or more H atoms may be replaced by F, Cl, Br, I and / or CN.

[0046] In particular, where the group R 1 , R 2 , R 3 , R 4 , R 5 , R 6 In the case of an aryl or heteroaryl group as defined above, R 7More preferably, they are selected from the group consisting of F, Cl, Br, I, CN, NH2, N(R 8 )2、OH、NHC(O)R 8 , OR 8 , an acrylate group (—OC(O)CHCH2) or a methacrylate group (—OC(O)C(CH3)CH2), a linear alkyl group having 1 to 20 C atoms, a branched alkyl group having 3 to 20 C atoms, wherein one or more H atoms in the linear or branched alkyl group may be replaced by F, Cl, Br, I and / or CN; and R 8 are selected identically or differently from linear alkyl radicals having 1 to 10 C atoms and branched alkyl radicals having 3 to 10 C atoms, wherein one or more H atoms may be replaced by F, Cl, Br, I and / or CN.

[0047] In particular, where the group R 1 , R 2 , R 3 , R 4 , R 5 , R 6 In the case of an alkyl group as defined above, the alkyl group may more preferably be substituted by one or more groups selected from the group consisting of F, Cl, Br, I, CN, an acrylate group (—OC(O)CHCH2) or a methacrylate group (—OC(O)C(CH3)CH2), an aromatic group having 5 to 20 aromatic ring atoms and a heteroaromatic group having 5 to 20 aromatic ring atoms.

[0048] According to a preferred embodiment of the present invention, R 1 , R 2 and R 3 At least one of R 4 , R 5 and R 6 More preferably, at least one of R 1 , R 2 and R 3 At least one of R 4 , R 5 and R 6 At least one of the groups is an aryl group.

[0049] For example, in the compound represented by formula (1), R 1 is an aryl or heteroaryl group as defined above, and R 2 and R 3 are identical or different alkyl groups as defined above. 2 is an aryl or heteroaryl group as defined above, and R 1and R 3 are identical or different alkyl groups as defined above. 3 is an aryl or heteroaryl group as defined above, and R 1 and R 2 Identically or differently are alkyl groups as defined above.

[0050] For example, in the compound represented by formula (2), R 4 is an aryl or heteroaryl group as defined above, and R 5 and R 6 are identical or different alkyl groups as defined above. 5 is an aryl or heteroaryl group as defined above, and R 4 and R 6 are identical or different alkyl groups as defined above. 6 is an aryl or heteroaryl group as defined above, and R 4 and R 5 Identically or differently are alkyl groups as defined above.

[0051] According to another preferred embodiment of the present invention, R 1 , R 2 and R 3 At least two of them and R 4 , R 5 and R 6 At least two of R are identical or different and are selected from aryl and heteroaryl groups. More preferably, R 1 , R 2 and R 3 At least two of them and R 4 , R 5 and R 6 At least two of the are identically or differently selected from aryl groups.

[0052] For example, in the compound represented by formula (1), R 1 and R 2 are identically or differently aryl and / or heteroaryl groups as defined above, and R 3 is an alkyl group as defined above. Alternatively, R 1 and R 3 are identically or differently aryl and / or heteroaryl groups as defined above, and R 2 is an alkyl group as defined above. Alternatively, R 2 and R 3 are identically or differently aryl and / or heteroaryl groups as defined above, and R 1 is an alkyl group as defined above.

[0053] For example, in the compound represented by formula (2), R 4 and R 5 are identically or differently aryl and / or heteroaryl groups as defined above, and R 6 is an alkyl group as defined above. Alternatively, R 4 and R 6 are identically or differently aryl and / or heteroaryl groups as defined above, and R 5 is an alkyl group as defined above. Alternatively, R 5 and R 6 are identically or differently aryl and / or heteroaryl groups as defined above, and R 4 is an alkyl group as defined above.

[0054] According to another preferred embodiment of the present invention, R in formula (1) 1 , R 2 , R 3 and R in formula (2) 4 , R 5 and R 6 and R and R are identically or differently selected from aryl and heteroaryl groups, more preferably selected from aryl groups, for example as defined above.

[0055] More preferably, R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are selected, identically or differently, from aromatic radicals having 5 to 18 aromatic ring atoms and heteroaromatic radicals having 5 to 18 aromatic ring atoms, even more preferably exclusively from aromatic radicals having 5 to 18 aromatic ring atoms, which may in each case be substituted by one or more radicals R 7 replace;

[0056] Where R 7 are selected from the group consisting of F, Cl, Br, I, CN, NH2, N(R 8 )2、OH、NHC(O)R 8 , OR 8 , acrylate groups (—OC(O)CHCH2) or methacrylate groups (—OC(O)C(CH3)CH2), linear alkyl groups having 1 to 20 C atoms, branched alkyl groups having 3 to 20 C atoms, wherein one or more H atoms in the linear or branched alkyl group may be replaced by F, Cl, Br, I and / or CN; and

[0057] R 8are selected identically or differently from linear alkyl radicals having 1 to 10 C atoms and branched alkyl radicals having 3 to 10 C atoms, wherein one or more H atoms may be replaced by F, Cl, Br, I and / or CN.

[0058] According to another preferred embodiment of the present invention, all R 1 , R 2 and R 3 And all R in formula (2) 4 , R 5 and R 6 is an alkyl group, for example as defined above.

[0059] More preferably, R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are selected, identically or differently, from straight-chain alkyl groups having 1 to 20 C atoms and branched alkyl groups having 3 to 20 C atoms, which may in each case be substituted by one or more radicals selected from the group consisting of F, Cl, Br, I, CN, acrylate groups (—OC(O)CHCH2) or methacrylate groups (—OC(O)C(CH3)CH2), aromatic groups having 5 to 20 aromatic ring atoms, and heteroaromatic groups having 5 to 20 aromatic ring atoms.

[0060] In relation to the above, it is further preferred according to the present invention that the group R in formula (1) 1 , R 2 , R 3 At least one of the groups R in formula (2) 4 , R 5 and R 6 At least one of the groups includes an acrylate (—OC(O)CHCH2) or methacrylate (—OC(O)C(CH3)CH2) functional group. That is, preferably the group R in formula (1) 1 , R 2 , R 3 At least one of the groups R in formula (2) 4 , R 5 and R 6 At least one of R is substituted with one or more acrylate groups (-OC(O)CHCH2) or methacrylate groups (-OC(O)C(CH3)CH2). 1 , R 2 , R 3 , R 4 , R 5 , R 6Whether identically or differently, they are alkyl groups, aryl groups, heteroaryl groups, aralkyl groups, heteroaralkyl groups, alkaryl groups or alkylheteroaryl groups.

[0061] It has surprisingly been found that if the compounds of the general formulae (1) and (2) comprise acrylate and / or methacrylate groups, crosslinking with polymerizable additives (e.g. polymerizable matrix materials) optionally contained in the composition according to the invention (see below) can be achieved, thereby further improving the stability of the nanosized luminescent material.

[0062] Further preferably, Z is P in the compounds of formula (1) and (2).

[0063] Particularly preferred compounds according to the general formula (1) and (2) are listed in the following table:

[0064]

[0065] It is further preferred according to the invention that the composition comprises at least one compound of the general formula (1) or at least one compound of the general formula (2).

[0066] The total amount of the compounds of formula (1) and / or (2) in the composition is preferably in the range of 1 wt % to 40 wt %, more preferably 4 wt % to 32 wt %, and even more preferably 4 wt % to 20 wt %, based on the inorganic part of the one or more nano-sized luminescent materials contained in the composition (i.e., the quantum material or quantum dot part without any possible one or more organic coatings). If the total amount of the compounds of formula (1) and / or (2) is within the above range, the best results with respect to the stabilization effect and high quantum yield can be achieved, but it is not limited thereto.

[0067] According to the present invention, it may be further preferred that the composition further comprises a surface-modified ligand attached to the surface of the at least one nano-sized luminescent material, and the ligand is preferably represented by the following general formula (3) or (4):

[0068] R 9 -SH Formula (3)

[0069] R 10 -(CH2) n -SH Formula (4)

[0070] in

[0071] R 9 is selected from linear alkyl groups having 1 to 40 C atoms, branched or cyclic alkyl groups having 3 to 40 C atoms and alkenyl or alkynyl groups having 2 to 40 C atoms;

[0072] R10 is selected from aromatic or heteroaromatic radicals having 5 to 30 aromatic ring atoms, which may in each case be substituted by one or more radicals selected from the group consisting of F, Cl, Br, I, CN, straight-chain alkyl radicals having 1 to 20 C atoms and alkoxy radicals having 3 to 20 C atoms; and

[0073] n is 0 to 16.

[0074] That is, at least one nanosized luminescent material contained in the composition of the present invention in combination with the at least one compound of formula (1) or (2) may have a surface-modified ligand attached or bound (these terms are used interchangeably herein) to its surface, which is preferably selected from the compounds represented by general formula (3) or (4).

[0075] The ligands represented by the general formula (3) or (4) have been shown to be very effective in improving the stability of nano-sized luminescent materials (e.g. quantum dots), in particular against free radical treatment. It has surprisingly been found that by combining a thiol-containing ligand with a compound of the general formula (1) and / or (2) in the composition of the present invention, the stability of the nano-sized luminescent material, in particular against both free radical and thermal treatment, can be further improved.

[0076] -Nano-sized luminescent materials

[0077] According to the present invention, as the inorganic part of the nano-sized light-emitting material, various known semiconductor nano-sized light-emitting materials can be used as needed.

[0078] The term "nano" or "nano-sized" means a size in the range of 0.1 nm to 999 nm, preferably 1 nm to 150 nm, more preferably 3 nm to 50 nm.

[0079] Therefore, according to the present invention, the nano-sized luminescent material is taken to mean a luminescent material having a size in the range of 0.1 nm to 999 nm, preferably 0.1 nm to 150 nm, more preferably 3 nm to 50 nm.

[0080] According to the present invention, the term "size" means the average diameter of the longest axis of the nanosized luminescent particles. The average diameter of the nanosized luminescent particles is calculated based on 100 luminescent nanoparticles in a TEM image created by a Tecnai G2Spirit Twin T-12 transmission electron microscope.

[0081] The shape type of the nanometer-sized luminescent material of the present invention is not particularly limited. Any type of nanometer-sized luminescent material can be used, such as spherical, elongated, star-shaped, polyhedral, tetrapod, tetrahedral, platelet-shaped, conical and irregularly shaped semiconductor nanometer-sized luminescent particles.

[0082] In a preferred embodiment of the present invention, the nano-sized luminescent material may be selected from nano-sized inorganic phosphor materials, quantum-sized materials such as quantum dots or quantum rods, and any combination of these materials.

[0083] More preferably, the nano-sized luminescent material is a quantum-sized material, further preferably a quantum dot material, a quantum rod material or a combination of any of these materials.

[0084] As used herein, the term "quantum size" means the size of the inorganic semiconductor light-emitting material itself, i.e., the size of the inorganic semiconductor light-emitting material without ligands or any other surface modifications, which can show a quantum confinement effect, as described in, for example, ISBN: 978-3-662-44822-9. Generally, it is said that quantum size materials such as quantum dot materials and / or quantum rod materials can emit tunable, sharp and vivid colored light due to the "quantum confinement" effect.

[0085] Preferably, the size of the overall structure of the quantum size material is from 1 nm to 100 nm, more preferably from 1 nm to 30 nm, even more preferably from 5 nm to 15 nm.

[0086] As quantum dots, publicly available quantum dots can be preferably used as needed, for example, CdSeS / ZnS alloy quantum dots product numbers 753793, 753777, 753785, 753807, 753750, 753742, 753769, 753866, InP / ZnS quantum dots product numbers 776769, 776750, 776793, 776777, 776785, PbS core-type quantum dots product numbers 747017, 747025, 747076, 747084, or CdSe / ZnS alloy quantum dots product numbers 754226, 748021, 694592, 694657, 694649, 694630, 694622 from Sigma-Aldrich.

[0087] In another preferred embodiment of the present invention, the nano-sized luminescent material is a semiconductor luminescent nanoparticle having a core-shell structure, wherein the core is surrounded by one or more shell layers.

[0088] According to the present invention, the one or more shells of the semiconductor luminescent nanoparticles are preferably single shells, double shells or multiple shells having more than two shells, and most preferably double shells.

[0089] As used herein, the term "shell" means a structure that completely or partially covers the core. Preferably, the one or more shells completely cover the core. The terms "core" and "shell" are well known in the art and are commonly used in the field of quantum materials, such as US 8221651B2.

[0090] According to the present invention, the core of the semiconductor light-emitting nanoparticle can be varied. For example, CdS, CdSe, CdTe, ZnS, ZnSe, ZnSeS, ZnTe, ZnO, GaAs, GaP, GaSb, HgS, HgSe, HgSe, HgTe, InAs, InP, InPS, InPZnS, InPZn, InPGa, InSb, AlAs, AlP, AlSb, Cu2S, Cu2Se, CuInS2, CuInSe2, Cu2(ZnSn)S4, Cu2(InGa)S4, TiO2 alloys and any combination of these substances can be used.

[0091] In a preferred embodiment of the present invention, the core of the semiconductor light-emitting nanoparticles comprises one or more elements of Group 13 of the Periodic Table and one or more elements of Group 15 of the Periodic Table, such as GaAs, GaP, GaSb, InAs, InP, InPS, InPZnS, InPZn, InPGa, InSb, AlAs, AlP, AlSb, CuInS2, CuInSe2, Cu2(InGa)S4 and any combination of these substances.

[0092] Even more preferably, the core comprises In and P atoms, such as InP, InPS, InPZnS, InPZn or InPGa.

[0093] According to another preferred embodiment of the present invention, at least one of the shell layers comprises a first element of group 12, 13 or 14 of the periodic table and a second element of group 15 or 16 of the periodic table. Preferably, all shell layers comprise a first element of group 12, 13 or 14 of the periodic table and a second element of group 15 or 16 of the periodic table.

[0094] More preferably, at least one of the shells comprises a first element of group 12 of the periodic table and a second element of group 16 of the periodic table. For example, CdS, CdZnS, ZnS, ZnSe, ZnSSe, ZnSSeTe, CdS / ZnS, ZnSe / ZnS or ZnS / ZnSe shells may be used. Even more preferably, all shells comprise a first element of group 12 of the periodic table and a second element of group 16 of the periodic table.

[0095] Particularly preferably, at least one shell layer is represented by the following formula (5),

[0096] ZnS x Se y Te z, Formula (5):

[0097] Wherein 0≤x≤1, 0≤y≤1, 0≤z≤1, and x+y+z=1, wherein even more preferably 0≤x≤1, 0≤y≤1, z=0, and x+y=1.

[0098] Most preferably ZnS, ZnSe, ZnSeS, ZnSeSTe, CdS / ZnS, ZnSe / ZnS, ZnS / ZnSe shells are used.

[0099] It is further preferred that all shell layers are represented by formula (5).

[0100] For example, as core-shell semiconductor luminescent nanoparticles for green and / or red emission purposes, CdSe / CdS, CdSeS / CdZnS, CdSeS / CdS / ZnS, ZnSe / CdS, CdSe / ZnS, InP / ZnS, InP / ZnSe, InP / ZnSe / ZnS, InP / ZnS / ZnSe, InPZn / ZnS, InPZn / ZnSe / ZnS, InPZn / ZnS, InPZn / ZnSe / ZnS, InPZn / ZnS / ZnSe, ZnSe / CdS, ZnSe / ZnS semiconductor luminescent nanoparticles or any combination of these substances can be used.

[0101] More preferably, InP / ZnS, InP / ZnSe, InP / ZnSe / ZnS, InP / ZnS / ZnSe, InPZn / ZnS, InPZn / ZnSe / ZnS, InPZn / ZnS / ZnSe can be used.

[0102] In a preferred embodiment of the present invention, the shell layer of the semiconductor luminescent nanoparticle is a double shell layer.

[0103] The semiconductor luminescent nanoparticles are publicly available, for example from Sigma-Aldrich, and / or described in, for example, the following documents: ACS Nano, 2016, 10(6), pages 5769-5781, Chem. Moter. 2015, 27, 4893-4898, and International Patent Publication WO2010 / 095140A2.

[0104] Therefore, according to a preferred embodiment of the present invention, the composition comprises, consists essentially of, or consists of:

[0105] a) at least one semiconductor luminescent nanoparticle comprising a core and optionally at least one shell layer, and

[0106] b) at least one compound represented by the general formula (1) or (2) as defined above.

[0107] According to another preferred embodiment of the present invention, the composition comprises, consists essentially of, or consists of:

[0108] a) at least one semiconductor luminescent nanoparticle comprising a core, at least one optional shell layer and a surface-modified ligand represented by general formula (3) or (4) attached to the outermost particle surface, and

[0109] b) at least one compound represented by the general formula (1) or (2) as defined above.

[0110] In addition to the compounds of formula (1) and / or (2) and optionally the ligands of general formula (3) or (4), the nanometer-sized luminescent material, such as quantum rods and / or quantum dots and / or semiconductor luminescent nanoparticles, may further have one or more different types of surface-modified ligands attached to its surface. Thus, the outermost surface of the luminescent material or the shell of the semiconductor luminescent nanoparticle may be overcoated with one or more surface-modified ligands together with the compounds of formula (1) and / or (2) and optionally with the ligands of general formula (3) or (4).

[0111] Without wishing to be bound by theory, it is believed that such surface ligands can lead to easier dispersion of the nano-sized luminescent material in a solvent. These commonly used surface ligands include phosphines and phosphine oxides, such as trioctylphosphine oxide (TOPO), trioctylphosphine (TOP) and tributylphosphine (TBP); phosphonic acids, such as dodecylphosphonic acid (DDPA), tridecylphosphonic acid (TDPA), octadecylphosphonic acid (ODPA) and hexylphosphonic acid (HPA); amines, such as oleylamine, dodecylamine (DDA), tetradecylamine (TDA), hexadecylamine (HDA) and octadecylamine (ODA), oleylamine (OLA), 1-octadecene (ODE), thiols, such as hexadecylmercaptan and hexanethiol; mercaptocarboxylic acids, such as mercaptopropionic acid and mercaptoundecanoic acid; carboxylic acids, such as oleic acid, stearic acid, myristic acid; acetic acid and combinations of any of these substances. And polyethyleneimine (PEI) can also be preferably used.

[0112] Examples of surface ligands have been described, for example, in published international patent application WO 2012 / 059931A.

[0113] -Other additives

[0114] If desired, the composition of the present invention may contain other additives. Examples of additional additives include, but are not limited to, organic light emitting materials, inorganic light emitting materials, charge transport materials, scattering particles, host materials, nano-sized plasma particles, photoinitiators, and matrix materials.

[0115] The inorganic fluorescent material can preferably be selected from one or more of sulfides, thiogallates, nitrides, oxynitrides, silicates, aluminates, apatites, borates, oxides, phosphates, halophosphates, sulfates, tungstates, tantalates, vanadates, molybdates, niobates, titanates, germanates, halide-based phosphors and any combination of these substances.

[0116] The suitable inorganic fluorescent materials described above may be known phosphors, including nano-sized phosphors, quantum-sized materials, as mentioned in the following documents: Phosphor Handbook, Second Edition (CRC Press, 2006), pages 155-338 (WM Yen, S. Shionoya and H. Yamamoto), WO2011 / 147517A, WO2012 / 034625A and WO2010 / 095140A.

[0117] According to the present invention, any type of known materials can be preferably used as the organic light-emitting material and charge transport material, such as well-known organic fluorescent materials, organic host materials, organic dyes, organic electron transport materials, organic metal complexes and organic hole transport materials.

[0118] As scattering particles, small particles of inorganic oxides, such as SiO2, SnO2, CuO, CoO, Al2O3, TiO2, Fe2O3, Y2O3, ZnO, MgO; organic particles, such as polymerized polystyrene, polymerized PMMA; inorganic hollow oxides, such as hollow silica, or a combination of any of these substances can be preferably used.

[0119] According to the present invention, as the light scattering particles, any type of known light scattering particles having a different refractive index from the matrix material of the layer including the light scattering particles and capable of producing Mie scattering effect can be preferably used as required.

[0120] According to the present invention, various known transparent polymers suitable for optical devices can be preferably used as the matrix material.

[0121] According to the present invention, the term "transparent" means at least about 60% transmission of incident light at the thickness used in the optical medium and at the wavelength or wavelength range used during operation of the optical medium. Preferably, it exceeds 70%, more preferably, exceeds 75%, and most preferably, exceeds 80%.

[0122] In a preferred embodiment of the present invention, any type of known transparent polymers described in, for example, WO 2016 / 134820A may be used.

[0123] According to the present invention, the term "polymer" means a material having a repeating unit and having a weight average molecular weight (Mw) of 1000 g / mol or more.

[0124] The molecular weight Mw is determined by GPC (= gel permeation chromatography) using polystyrene as internal standard.

[0125] In some embodiments of the present invention, the transparent polymer has a glass transition temperature (Tg) of 70° C. or more and 250° C. or less.

[0126] Tg is measured based on the change in heat capacity observed in differential scanning calorimetry as described, for example, in: http: / / pslc.ws / macrog / dsc.htm ; Rickey J Seyler, Assignment of the Glass Transition, ASTM Publication Number (PCN) 04-012490-50.

[0127] For example, as the transparent polymer used for the transparent matrix material, poly(meth)acrylate, epoxy resin, polyurethane, polysiloxane can be preferably used.

[0128] In a preferred embodiment of the present invention, the weight average molecular weight (Mw) of the polymer as the transparent matrix material is in the range of 1,000 to 300,000 g / mol, more preferably it is 10,000 to 250,000 g / mol.

[0129] - Formulations

[0130] The present invention further provides a formulation comprising a composition of the present invention as defined above and at least one solvent. Preferably, the solvent is selected from one or more of aromatic, halogenated and aliphatic hydrocarbon solvents, more preferably selected from one or more of toluene, xylene, ether, tetrahydrofuran, chloroform, dichloromethane, heptane, purified water, acetate, alcohol, sulfoxide, formamide, nitride, ketone.

[0131] The amount of solvent in the formulation can be freely controlled according to the coating method of the composition. For example, if the composition is to be sprayed, it can contain 90% by weight or more of the solvent. In addition, if the slit coating method often used in coating large substrates is to be implemented, the amount of the solvent is generally 60% by weight or more, preferably 70% by weight or more.

[0132] -use

[0133] The invention further relates to the use of a composition according to the invention as defined above or a formulation according to the invention as defined above in a process for producing an optical medium.

[0134] The method for producing an optical medium preferably comprises the following steps 1) and 2) in sequence:

[0135] 1) providing a composition of the invention as defined above or a formulation of the invention as described above onto a substrate, and

[0136] 2) applying heat to the composition or formulation provided onto the substrate.

[0137] In order to provide the composition or formulation onto the substrate according to step 1), any type of known coating method may be preferably used, for example, dip coating, gravure coating, roller coating, rod coating, brush coating, spray coating, blade coating, flow coating, spin coating and slot coating.

[0138] The substrate to be coated in step 1) is also not particularly limited, and it can be appropriately selected from, for example, a silicon substrate, a glass substrate, and a polymer or resin film. The substrate can be solid or flexible, and transparent or opaque.

[0139] The step 2) of applying heat to the composition or formulation provided on the substrate is for the purpose of drying and reducing the solvent remaining therein.

[0140] The heating is preferably performed on a hot plate at a temperature of 50 to 150° C., more preferably 90 to 150° C., for 10 to 300 seconds, preferably 30 to 120 seconds, or in a clean oven for 1 to 30 minutes. In addition, as required, the step of providing the composition or formulation onto the substrate may be repeated once or twice or more to form a coating or film of desired thickness.

[0141] In a preferred embodiment of the present invention, optionally after step 2), a polymerization step 3) can be applied to the dried composition or formulation provided on the substrate, for example by exposure to radiation.

[0142] As a radiation source for the exposure, any light source used in a conventional pattern forming method can be adopted. According to the present method, there is no particular limitation on the environmental conditions in the exposure, and the exposure can be performed under an ambient atmosphere (standard atmospheric pressure) or under a nitrogen atmosphere.

[0143] After the optional polymerization step 3), optionally, a post-exposure bake can be performed as needed, the purpose of which is to promote the inter-polymer reaction caused by the reaction initiator in the exposed area of ​​the coating. The temperature of the post-exposure bake is preferably 40 to 150° C., more preferably 60 to 150° C. The post-exposure bake step can be implemented using a hot plate, an oven, a furnace or the like. There is no particular restriction on the atmosphere during the baking process. The baking time is preferably 20 to 500 seconds, more preferably 40 to 300 seconds, to maintain a higher uniformity of the thermal balance in the wafer surface and also to prevent the diffusion of the acid.

[0144] The optical medium thus obtained (which may be an optical sheet, such as a color filter, a color conversion film, a remote phosphor strip or another film or filter) has increased stability, in particular thermal stability, and can achieve high quantum yields.

[0145] The invention therefore also relates to an optical medium obtained or obtainable by the manufacturing method of the invention.

[0146] Furthermore, the present invention relates to the use of a composition according to the invention as defined above or a formulation according to the invention as defined above in an electronic device, an optical device, in a biomedical device or for the manufacture of an electronic, optical or biomedical device.

[0147] A method for manufacturing an electronic device, an optical device or a biomedical device (the device is defined below) comprises the following steps A):

[0148] A) Providing an optical medium prepared according to the method of the present invention as described above in an electronic device, an optical device or a biomedical device.

[0149] -Optical media

[0150] The invention further relates to an optical medium comprising a composition according to the invention as defined above.

[0151] The optical medium may be an optical sheet such as a color filter, a color conversion film, a remote phosphor stripe, or another film or filter.

[0152] According to the present invention, the term "sheet" includes thin films and / or layered structured media.

[0153] Preferably, the optical medium comprises an anode and a cathode, and at least one layer comprising the composition of the invention. Preferably, the one layer is an organic layer, more preferably, the organic layer is a light-emitting layer.

[0154] Preferably, the light-emitting layer comprises at least one organic material selected from hole transport materials, electron transport materials, host materials, hole injection materials, electron injection materials, as described in the following documents: WO 2018 / 024719 A1, US2016 / 233444 A2, US7754841 B, WO 2004 / 037887 and WO 2010 / 097155.

[0155] The total amount of the composition in the light emitting layer is in the range of 0.001 wt % to 99.99 % based on the total amount of the light emitting layer.

[0156] More preferably, the medium further comprises one or more additional layers selected from the group consisting of a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron blocking layer and an electron injection layer.

[0157] According to the present invention, any kind of publicly available inorganic and / or organic materials for hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron blocking layer and electron injection layer can be preferably used, as described in the following documents: WO 2018 / 024719 A1, US2016 / 233444 A2, US7754841 B, WO 2004 / 037887 and WO 2010 / 097155.

[0158] Preferably, the anode and cathode of the optical medium sandwich the organic layer. More preferably, the additional layer is also sandwiched by the anode and cathode.

[0159] Particularly preferably, the organic layer comprises the composition of the present invention and a host material, preferably, the host material is an organic host material.

[0160] -Optics

[0161] The present invention further provides an optical device comprising the optical medium of the present invention.

[0162] The optical device may preferably be a liquid crystal display device (LCD), an organic light emitting diode (OLED), a backlight unit for an optical display, a light emitting diode device (LED), a microelectromechanical system (MEMS), an electrowetting display or an electrophoretic display, a lighting device and / or a solar cell.

[0163] The present invention will be described in more detail below with reference to the following examples, which are merely illustrative and do not limit the scope of the present invention.

[0164] Working Example

[0165] Working Example 1 - Synthesis of InP / ZnSe Quantum Materials

[0166] 0.7 μL InP cores were prepared using a publicly available method (such as described in WO 2018 / 215396 A1), which was then mixed with 600 μL toluene and transferred to a four-necked flask. 18.8 mL oleylamine and 4.4 mL ZnCl2 were then added. The mixture was kept at 35 °C under vacuum for 30 minutes. The mixture was then heated to 250 °C under argon for 30 minutes.

[0167] After the above nuclear treatment, the mixture was cooled to 190°C and 10.4 mL of ZnCl2 in oleylamine was added. At 180°C, 1.8 mL of TOP:Se (2M) was injected. The mixture was heated to 200°C for 30 minutes, then heated to 320°C, and then 12.4 mL of zinc undecylanate (0.4 M) in oleylamine was injected.

[0168] Working Example 2 - Purification of the quantum material from Example 1.

[0169] 1 mL of the sample obtained from Example 1 was purified to remove excess ligands using toluene and ethanol as solvent and antisolvent, respectively, and then centrifuged and dried. The cleaning was repeated twice. The obtained solid was then dissolved in hexane and centrifuged again. The hexane was evaporated and the quantum dots were dissolved in toluene. The amount of organic ligands was calculated using thermogravimetric analysis (TGA) (model TGA2, Metler Toledo). TG analysis showed an organic content of 15 wt %.

[0170] 30 mg of the obtained quantum dots were dissolved in 1 mL of toluene (30 mg / mL). The quantum yield (QY) was measured using a Hamamatsu absolute quantum yield spectrometer (model: Quantaurus C11347).

[0171] Working Example 3 - Stability of the quantum material from Example 2 in thermal testing

[0172] 0.5 mL of quantum dots (30 mg / mL) in toluene were dried under argon to remove toluene. The vial was then opened to air and heated at 150°C for 1 hour. The solid was then redissolved in toluene and the QY was measured using a Hamamatsu absolute quantum yield spectrometer (model: Quantaurus C11347).

[0173] Working Example 4 - Stability of the Quantum Material from Example 2 with TPO, PPO, TOPO, TPPO, TOP and BPh in thermal testing.

[0174] 0.5 mL of quantum dots (30 mg / mL) in toluene was added separately to another vial containing 1.2 mg (8 wt%) of each of the following additives: TPO, PPO, TOPO, TPPO, TOP, and BPh (see Table 1 below). The toluene was evaporated, and the vial was opened to air and heated at 150° C. for 1 hour. The solid was then redissolved in toluene and the QY was measured using a Hamamatsu absolute quantum yield spectrometer (model: Quantaurus C11347).

[0175] Working Example 5 - Stability of the quantum material from Example 2 after functionalization with benzenethiol (BT) and addition of TPO in thermal testing

[0176] 0.5 mL of quantum dots (30 mg / mL) in toluene were mixed with 18 mg of benzenethiol for 16 hours. Excess thiol was washed by adding 2 mL of ethanol. The QDs were dried, redissolved in toluene and added to another vial containing 1.2 mg (8 wt %) TPO. The toluene was evaporated and the vial was opened to air and heated at 150 ° C for 1 hour. The solid was then redissolved in toluene and the QY was measured using a Hamamatsu absolute quantum yield spectrometer (Model: Quantaurus C11347).

[0177] The same experiment was performed without TPO (only BT) for comparison.

[0178] Working Example 6 - Synthesis of InP / ZnSeS Quantum Materials

[0179] 0.7 μL of InP cores were mixed with 600 μL of toluene and transferred to a four-necked flask. Then 14.8 mL of oleylamine and 4.4 mL of ZnCl2 were added. The mixture was kept at 35°C for 30 minutes under vacuum. Then, the mixture was heated to 250°C under argon for 30 minutes.

[0180] After the above nuclear treatment, the mixture was cooled to 190°C and 10.4 mL of ZnCl2 in oleylamine was added. At 180°C, 1.8 mL of TOP:Se (2M) was injected. The mixture was heated to 200°C for 30 minutes, then heated to 320°C, and then 12.4 mL (0.4 M) of zinc undecanoate in oleylamine and 0.54 mL of dodecanethiol were added dropwise.

[0181] Working Example 7 - Purification of the quantum material obtained from Example 6

[0182] Using toluene and ethanol as solvent and antisolvent, 1 mL of the sample obtained from Example 6 was purified to remove excess ligands, then centrifuged and dried. The cleaning was repeated twice. The obtained solid was then dissolved in hexane and centrifuged. The hexane was evaporated and the quantum dots were dissolved in toluene. The amount of organic ligands was calculated using thermogravimetric analysis (TGA) (model TGA2, Metler Toledo). TG analysis showed that the organic content was 15 wt %.

[0183] 30 mg of the obtained quantum dots were dissolved in 1 mL of toluene (30 mg / mL). QY was measured using a Hamamatsu absolute quantum yield spectrometer (model: Quantaurus C11347).

[0184] Working Example 8 - Stability of the quantum material from Example 7 in thermal testing

[0185] 0.5 mL of quantum dots (30 mg / mL) in toluene were dried under argon to remove toluene. The vial was then opened to air and heated at 150°C for 1 hour. The solid was then redissolved in toluene and the QY was measured using a Hamamatsu absolute quantum yield spectrometer (model: Quantaurus C11347).

[0186] Working Example 9 - Stability of Quantum Material from Example 7 and TPO in Thermal Testing

[0187] 0.5 mL of quantum dots (30 mg / mL) in toluene was added to another vial containing 1.2 mg (8 wt%) TPO. The toluene was evaporated and the vial was opened to air and heated at 150°C for 1 hour. The solid was then redissolved in toluene and the QY was measured using a Hamamatsu absolute quantum yield spectrometer (model: Quantaurus C11347).

[0188] List of abbreviations of the additive compounds used:

[0189] TPO diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide

[0190] PPO Phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide

[0191] TOPO Trioctylphosphine oxide

[0192] TPPO Triphenylphosphine oxide

[0193] TOP Trioctylphosphine

[0194] BPh Benzophenone

[0195] Table 1: Quantum yield of QDs

[0196]

[0197]

[0198] *When the same experiment was performed under inert conditions, the QY increased from 43% to 52% in the case of 8 wt% TPO.

[0199] As can be seen from Table 1 above, when the nanosized luminescent material is combined with the compounds TPO or PPO according to the present invention (these compounds contain phosphine oxide (P=O) and ketone (C=O) groups), the thermal stability of InP / ZnSe QDs (Examples 1 to 4) and the thermal stability of InP / ZnSeS QDs (Examples 6 to 9) at 150°C under air are improved, as indicated by the observed quantum yields.

[0200] On the other hand, additive compounds with only phosphine oxide groups (TOPO and TPPO) or only keto (C=O) groups (BPh) or neither phosphine oxide nor keto groups (TOP) did not show any advantage over the original natural ligand. When thermally tested with TPO under inert conditions, the QY could be increased from 43% to >50%.

[0201] The combination of TPO and BT (benzenethiol) as an additive to the QDs has a dual advantage, as indicated in Table 1 Example 5: stability against free radicals and thermal stability are improved. Functionalization of QDs with BT alone prevents free radical damage, but does not protect the QDs from heat. However, when BT is combined with TPO, stability against free radicals as well as stability against heat can be obtained.

Claims

1. A composition comprising at least one nano-sized luminescent material and at least one compound represented by the following general formula (1) or (2): in R 1 , R 2 , R 3 , R 4 , R 5 , R 6 are selected, identically or differently, from aromatic groups having 5 to 18 aromatic ring atoms; and Z is P, As or Sb; wherein the total amount of the compound represented by formula (1) and / or (2) in the composition is in the range of 4 wt % to 20 wt % based on the inorganic portion of the nano-sized luminescent material contained in the composition; and It further comprises a surface-modifying ligand attached to the surface of the at least one nano-sized luminescent material, wherein the ligand is represented by the following general formula (4): R 10 -(CH2) n -SH type (4) in R 10 is selected from aromatic groups having 5 to 30 aromatic ring atoms; and n is 0 to 16.

2. A composition according to claim 1, wherein Z is P.

3. The composition according to claim 1 or 2, wherein the composition comprises at least one compound of the general formula (1) or at least one compound of the general formula (2).

4. The composition according to claim 1 or 2, wherein the composition further comprises an additive.

5. A formulation comprising a composition according to any one of claims 1 to 4 and at least one solvent.

6. Use of a composition according to any one of claims 1 to 4 or a formulation according to claim 5 in a process for producing an optical medium.

7. Use of a composition according to any one of claims 1 to 4 or a formulation according to claim 5 in electronic devices, optical devices or in biomedical devices.

8. Optical medium comprising a composition according to any one of claims 1 to 4.

9. An optical device comprising the optical medium according to claim 8.

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