WO2019081401A1 - Points quantiques ayant une absorption élevée - Google Patents

Points quantiques ayant une absorption élevée

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Publication number
WO2019081401A1
WO2019081401A1 PCT/EP2018/078839 EP2018078839W WO2019081401A1 WO 2019081401 A1 WO2019081401 A1 WO 2019081401A1 EP 2018078839 W EP2018078839 W EP 2018078839W WO 2019081401 A1 WO2019081401 A1 WO 2019081401A1
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WIPO (PCT)
Prior art keywords
inp
preparing
carbon atoms
compound
shell
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PCT/EP2018/078839
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English (en)
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David MOCATTA
Amir Holtzman
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Merck Patent Gmbh
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Publication of WO2019081401A1 publication Critical patent/WO2019081401A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/70—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing phosphorus

Definitions

  • the present invention relates to quantum dots (QD) having a high absorption, a method for the preparation of said quantum dots, optical medium and an optical device.
  • QD quantum dots
  • Quantum dots are known in the prior arts. Quantum dots (QD) are a class of materials that offer various promising applications in fields related to light emission and absorption, e.g. in fields such as in-vivo imaging, light- emitting device manufacture, photodetection and solar energy conversion. For example, quantum dots may find application in transistors, solar cells, LEDs, diode lasers, medical imaging, quantum computing and a variety of other fields. Furthermore, QDs emitting in the visible electromagnetic spectrum may be of particular interest for lighting and display applications, e.g. for high brightness LEDs.
  • a quantum dot may be sufficiently small to exhibit distinct quantum mechanical properties.
  • a single QD can for example contain about 100 to even 100000 atoms, having a diameter that ranges from about 10 to 50 or more atoms, e.g. a diameter in the range of about 2 to about 10
  • nanocrystal exciton states can be achieved, such that intermediate properties are obtained between those of the bulk material and discrete molecules. Therefore, the characteristics of a quantum dot may be closely related to its size and shape, e.g. the band gap, which determines the frequency range of emitted light, may be inversely related to its size.
  • Monodisperse ensembles of QDs may feature a narrow, size-tunable emission spectrum, while also being particularly suitable for solution-based processing.
  • Colloidal synthesis of nanocrystals may comprise the synthesis from precursor compounds in a solution. When heating the solution, the decomposed precursors form monomers that nucleate.
  • Known QDs obtainable by colloidal synthesis may comprise binary compounds, such as lead sulfide, lead selenide, cadmium selenide, cadmium sulfide, indium arsenide and indium phosphide, or ternary compounds such as cadmium selenide sulfide.
  • binary compounds such as lead sulfide, lead selenide, cadmium selenide, cadmium sulfide, indium arsenide and indium phosphide, or ternary compounds such as cadmium selenide sulfide.
  • Particular nanocrystals known in the art may involve cadmium chalcogenide based materials where especially CdSe QDs synthesis is a fully mastered process. Such nanocrystal can be easily manufactured due to the simplicity of their synthesis, and may have a high optical quality.
  • cadmium is a toxic heavy element which may be subject to legal restrictions, e.g. by the EU OHS directive. Consequently, the use of such materials in large amounts is preferably avoided. Furthermore, the high toxicity may limit the applicability of cadmium chalcogenide based
  • Cadmium-free alternatives for manufacturing quantum dots are known in the art, such as CulnS2 and InP.
  • Particularly indium phosphide (InP) QDs are known that have emission characteristics similar to CdSe QDs, while advantageously having a lower toxicity.
  • US 2015/0083969 A1 discloses an lnP/ZnS(F) core/shell nanocrystal particle.
  • WO 201 6/146719 A1 mentions a method for synthesizing nanoparticles by mixing a first precursor material comprising a first compound comprising a halide moiety and a metal or a metalloid, a second precursor material comprising a second compound comprising a polyatomic nonmetal, and a solvent and by heating up the mixture.
  • US 8679543 B2 describes a coated InP/ZnS core /shell nanocrystal.
  • Quantum dots obtainable according to prior art documents could be used. However, it is a permanent desire to improve the features of these quantum dots. Therefore, it is an object of embodiments of the present invention to provide quantum dots having a high absorption and efficiency.
  • quantum dots based on indium phosphide (InP) exhibiting a ratio of the optical density of the first exciton peak maximum to the optical density of the trough on the high energy side of the first exciton peak of above 1 .80 and below 2.5 in the absorption spectrum measured at 25°using a toluene solution.
  • the present invention relates to quantum dots (QD) based on magic sized clusters of indium phosphide (MSC InP) exhibiting a ratio of the optical density of the first exciton peak maximum to the optical density of the trough on the high energy side of the first exciton peak of above 1 .80 and below 2.5 in the absorption spectrum measured at 25° using a toluene solution.
  • QD quantum dots
  • MSC InP magic sized clusters of indium phosphide
  • the present invention relates to a method for preparing QD being based on InP.
  • the present invention relates to a method for preparing QD being based on InP MSCs.
  • the present invention also relates to QD being obtainable by a method for preparing QD.
  • the present invention further relates to composition comprising QD being based on InP.
  • the present invention also relates to an optical medium comprising QD being based on InP.
  • the present invention further relates to composition comprising QD being based on InP MSCs.
  • the present invention also relates to an optical medium comprising QD being based on InP MSCs.
  • the present invention provides quantum dots (QD) based on indium phosphide (InP) characterized in that the QD exhibit a ratio of the optical density of the first exciton peak maximum to the optical density of the trough on the high energy side of the first exciton peak of above 1 .80 and below 2.5 in the absorption spectrum measured at 25°using a toluene solution.
  • QD quantum dots
  • InP indium phosphide
  • Quantum dots are well known in the art as described above.
  • QD are a nanosized light emitting semiconductor material.
  • nanosized means the size in between 0,1 nm and 999 nm.
  • the term "a nanosized light emitting semiconductor material" is taken to mean that the light emitting material which size of the overall diameter is in the range from 0.5 nm to 999 nm. And in case of the material has elongated shape, the length of the overall structures of the light emitting material is in the range from 0.5 nm to 999 nm.
  • the term "nano sized” means the size of the semiconductor material itself without ligands or another surface modification, which can show the quantum size effect.
  • a type of shape of the core of the nanosized light emitting material, and shape of the nanosized light emitting material to be synthesized are not particularly limited. For examples, spherical shaped, elongated shaped, star shaped, polyhedron shaped, pyramidal shaped, tetrapod shaped, tetrahedron shaped, platelet shaped, cone shaped, and irregular shaped nanosized light emitting materials can be synthesized.
  • the QD exhibit a ratio of the peak maximum to the peak minimum of above 1 .80 and below 2.5 in the absorption spectrum at a wavelength in the range of 400 to 500 nm measured at 25°using a toluene solution.
  • the ratio of the peak maximum to the peak minimum is the ratio of the OD of the first exciton peak and the trough on the lower wavelength side of that peak.
  • the ratio of the peak maximum to the peak minimum in the absorption spectrum is related to the first exciton peak.
  • the data concerning the peak maximum in the absorption spectrum is obtained using a toluene solution of quantum material with an optical density (OD) of 0.09.
  • the QD are based on indium phosphide (InP). Therefore, the present QD comprise a measurable amount of InP.
  • the QD comprise a centre area of InP. More preferably, the centre area of InP comprises a diameter in the range of 0.8 to 5.0 nm, preferably 0.9 nm to 3.0 nm, more preferably 1 .0 to 1 .5 nm.
  • the size of the particles can be obtained by methods well known in the art. The particle size distribution is preferably assessed with Gatan Digital Micrograph software using images obtained from High Resolution Transmission
  • the sample preparation for performing the HRTEM can be performed by any conventional method.
  • the sample is purified before the measurement.
  • 0.2ml of the crude sample is dissolved in 0.2ml of chloroform; 1 .6ml of acetone is then added and the mixture is precipitated by centrifuge (5 minutes, 5Krpm).
  • the precipitant is dissolved in 0.5ml of chloroform, and 30uL from this solution is dropped on a Cu/C TEM grid with ultrathin amorphous carbon layer.
  • the grid is dried in vacuum at 80°C for 1 .5h to remove the residues of the solvent as well as possible organic residues.
  • HRTEM and/or other TEM measurements are preferably carried out on a Tecnai F20 G2 machine equipped with EDAX Energy Dispersive X-Ray Spectrometer.
  • the QD are based on magic sized clusters comprising indium phosphide, more preferably the QD are based on magic sized clusters essentially consisting of indium phosphide (MSC InP).
  • Magic sized clusters are well known in the art. MSC have a well-defined composition and exhibit remarkable thermodynamic stability relative to similar sizes.
  • the QD are based on a nanocrystal core, which consists solely of fused 6-membered rings with all phosphorus atoms coordinated to four indium atoms in a pseudo-tetrahedral arrangement.
  • the nanocrystal core preferably have the formula [ln 2 i P2o] 3+ , [ln 42 P4o] 6+ , [I nesPeo] 9 *, [ln 8 4Pso] 12+ , [ln 95 P9o] 15+ , [ln 3 i P 3 o] 3+ , [ ⁇ ⁇ 4 ⁇ ⁇ 0 ] 3+ , [ ⁇ ⁇ 5 ⁇ ⁇ 5 ⁇ ] 3+ , [ ⁇ ⁇ 6 ⁇ ⁇ 6 ⁇ ] 3+ , [ln 7 i P7o] 3+ ,
  • the subset of atoms preferably possesses a C2 rotation axis that bisects two phosphorus atoms and a single indium atom located at the center of the particle, and measures approximately 1 .3 nm ⁇ 1 .0 nm ⁇ 1 .0 nm.
  • a dihedral angle of 160 ⁇ 3° is consistent along the longest straight In-P.
  • the average In-P bond length in the [ln2i P2o] 3+ . core is 2.528 A (min 2.479 A, max 2.624 A), and the average P- In-P bond angle is 109.2°(min 97.7° , max 1 19.9 ⁇ ).
  • an additional 1 6 indium atoms are singly bound to this core through surface-exposed phosphorus atoms, with an average bond length of 2.482 A (min 2.450 A, max 2.515 A).
  • the sum of the single- bond covalent radii for In and P is 2.53 A and it is preferably inferred that the bonding in the inorganic core of this cluster may be best viewed as covalent in nature, with differences in bond lengths between In-P in the core and In-P at the surface arising from internal strain.
  • the structure is preferably assessed using single-crystal X-ray diffraction at 25°C as well known in the art. (see J. Am. Chem. Soc. 201 6, 138, 1510-1513).
  • the core of the present QD may comprise additional InP or areas having another structure.
  • the area comprising the preferred structure as mentioned above is at least 30% by volume, more preferably at least 50% by volume and even more preferably at least 70 % by volume.
  • the quantum dots may comprise a core / shell structure. Consequently, the QD may comprise a shell of a semiconductor.
  • core / shell structure means the structure having a core part and at least one shell part covering said core.
  • said core / shell structure can be core / one shell layer structure, core / double shells structure or core / multishell structure.
  • multishell stands for the stacked shell layers consisting of three or more shell layers. Each stacked shell layers of double shells and / or multishell can be made from same or different materials.
  • a quantum dot shell may comprise a shell of a semiconductor material comprising ll-VI, lll-V, or IV-VI semiconductors, or a combination of any of these.
  • ternary or quaternary materials of II, III, IV, V, VI materials of the periodic table can be used.
  • the shell comprises or consists of a 1 st element of group 12 of the periodic table and a 2 nd element of group 1 6 of the periodic table, preferably, the 1 st element is Zn, and the 2 nd element is S, Se and/or the shell comprises or a consisting of a 1 st element of group 13 of the periodic table and a 2 nd element of group 15 of the periodic table, preferably, the 1 st element is In, and the 2 nd element is P, more preferably the shell comprises or a consisting of InP, GaP, ZnS, ZnSe or combinations of these materials, especially alloys of these materials, even more preferably ZnSe or the shell comprises a mixture of ZnS and ZnSe.
  • GaP/ZnSe/ZnS GaZnP/ZnS, GaZnPS/ ZnS, GaZnP/ZnSe/ZnS,
  • the semiconducting material does not comprise Cd, more preferably the semiconducting material of the shell comprises ZnS and/or ZnSe, more preferably ZnSe or the shell comprises a mixture of ZnS and ZnSe.
  • the shell preferably comprises at least 20 % by weight, more preferably at least 40 % by weight, even more preferably at least 60 % by weight and most preferably at least 80 % by weight ZnSe based on the total weight of the shell.
  • the shell preferably comprises at least 40 % by weight, more preferably at least 70 % by weight, even more preferably at least 80 % by weight and most preferably at least 90 % by weight ZnSe in a specific layer of the shell.
  • the shell preferably has a thickness in the range of 0.3nm to 20nm, preferably 0.3nm to 10nm, more preferably 1 to 5nm, measured by taking images on a 120kV TEM and measuring the diameter of the quantum material for a sample of more than 50 particles and provided as arithmetic mean (number average). The measurement is preferably performed using imageJ software or the software mentioned above.
  • the shell thickness is calculated by subtracting the shelled particle thickness from the literature value of the MSCs e. g. 1 .0 or 1 .3nm and/or the particle being used for shelling.
  • the particle size of the shelled particles can be determined as mentioned above before shelling.
  • the size of the overall structures of the quantum dots is from 1 nm to 100 nm, more preferably, it is from 1 nm to 30 nm, even more preferably, it is from 2 nm to 15 nm.
  • the size is measured according to the method mentioned above and is based on the arithmetic mean (number average).
  • the surface of the quantum dots can be over coated with one or more kinds of surface ligands.
  • the QD preferably comprise a ligand.
  • the surface ligands in common use include phosphines and phosphine oxides such as Trioctylphosphine oxide (TOPO), Trioctylphosphine (TOP), and Tributylphosphine (TBP); phosphonic acids such as
  • DDPA Dodecylphosphonic acid
  • TDPA Tetradecylphosphonic acid
  • ODPA Octadecylphosphonic acid
  • HPA Hexylphosphonic acid
  • amines such as Oleylamine, Dedecyl amine (DDA), Tetradecyl amine
  • TDA Hexadecyl amine
  • Oleylamine Oleylamine
  • alkenes such as 1 -Octadecene (ODE)
  • thiols such as hexadecane thiol and hexane thiol
  • mercapto carboxylic acids such as mercapto propionic acid and mercaptoundecanoicacid
  • carboxylic acids such as oleic acid, stearic acid, myristic acid
  • PEI Polyethylenimine
  • the ligands mentioned above, especially the acids, can be used in acidic form and/or as a salt.
  • the person skilled in the art will be aware that the ligand will bind to the core in an appropriate manner, e.g. the acids may get deprotonated.
  • the QD comprise a carboxylate ligand, more preferably a carboxylate ligand having 2 to 30 carbon atoms, preferably 4 to 24 carbon atoms, even more preferably 8 to 20 carbon atoms, most preferably 10 to 26 carbon atoms, even more preferably a carboxylate ligand selected from the group consisting of myristate, palmitate, laurate, stearate, oleate; and/or a phosphorus containing ligand, such as phosphine ligands, preferably alkyl phosphine ligands having 3 to 108 carbon atoms, e. g.
  • Trioctylphosphine TOP
  • phosphine oxide ligands preferably alkyl phosphine oxide having 3 to 108 carbon atoms and/or phosphonate ligands, more preferably an alkyl phosphonate ligand having 1 to 36 carbon atoms, preferably 6 to 30 carbon atoms, even more preferably 10 to 24 carbon atoms, most preferably 12 or 20 carbon atoms in the alkyl group even more preferably a phosphonate ligand selected from the group consisting of octadecylphosphonate, dodecylphosphonate, tetradecylphosphonate, hexadecylphosphonate; and/or amines, preferably primary or secondary amines having 1 -36 carbon atoms, preferably 6 to 30.
  • carboxylate ligands such as stearate and oleate and phosphine ligands, such as Trioctylphosphine oxide (TOPO), Trioctylphosphine (TOP), and Tributylphosphine (TBP) are preferred.
  • TOPO Trioctylphosphine oxide
  • TOP Trioctylphosphine
  • TBP Tributylphosphine
  • a further subject matter of the present invention is a method for preparing quantum dots (QD) being based on indium phosphide (InP), characterized by preparing magic size cluster (MSC) of InP (MSC InP).
  • the method provides quantum dots (QD) based on indium phosphide (InP) exhibiting a ratio of the optical density of the first exciton peak maximum to the optical density of the trough on the high energy side of the first exciton peak of above 1 .80 and below 2.5 in the absorption spectrum measured at 25°using a toluene solution.
  • the method provides the preferred embodiments of the quantum dots (QD) of the present invention as mentioned above and below.
  • the InP magic size cluster can be prepared by any method known in the art.
  • the preparation of the MSC InP is achieved by a reaction mixture comprising a phosphorus precursor being selected from the group consisting of organic phosphine compounds, preferably alkylsilyl phosphine compounds having 1 to 3 silicon atoms preferably alkylsilyl phosphine compounds having 1 to 30 carbon atoms, preferably 1 to 10 carbon atoms, even more preferably 1 to 4 carbon atoms, most preferably 1 or 2 carbon atoms in the alkyl groups or aryl silyl phosphine compounds, preferably aryl silyl phosphine compounds having 1 -3 silicon atoms preferably aryl silyl phosphine compounds having 6 to 30 carbon atoms, preferably 6 to 18 carbon atoms, even more preferably 6 to 12 carbon atoms, most preferably 6 or 10 carbon atoms in the aryl groups.
  • the preparation of the MSC InP is preferably achieved by a reaction mixture comprising an indium precursor preferably being selected from the group consisting of indium carboxylates, more preferably indium carboxylates having 2 to 30 carbon atoms, preferably 4 to 24 carbon atoms, even more preferably 8 to 20 carbon atoms, most preferably 10 to 1 6 carbon atoms.
  • the indium carboxylate is preferably selected from the group consisting of indium myristate, indium laurate, indium palmitate, indium stearate and indium oleate.
  • the phosphorous precursor comprises
  • tris(trimethylsilyl)phosphine and similar materials having an aryl, and/or alkyl group instead of the methyl unit such as tris(triphenylsilyl)phosphine, tris(triethylsilyl)phosphine, tris(diphenylmethylsilyl)phosphine,
  • the preparation of the MSC InP is preferably achieved by a reaction mixture comprising a phosphorus precursor and an indium precursor being different to the phosphorus precursor and the molar ratio of the phosphorus precursor to the indium precursor is preferably in the range of 1 :3 to 1 :1 , preferably 1 :2.5 to 1 :1 , even more preferably 1 :2 to 1 :1 .
  • the preparation of the MSC InP is preferably achieved using a solvent. The solvent is not specifically restricted.
  • the solvent is selected from amines, aldehydes, alcohols, ketones, ethers, esters, amides, sulfur compounds, nitro compounds, hydrocarbons, halogenated hydro-carbons (e.g. chlorinated hydrocarbons), aromatic or heteroaromatic hydrocarbons, halogenated aromatic or heteroaromatic hydrocarbons and/or (cyclic) siloxanes, preferably cyclic hydrocarbons, terpenes, epoxides, ketones, ethers and esters.
  • a non-coordinating solvent is used.
  • an alkane more preferably a squalane is used as a solvent for the preparation of the MSC InP.
  • an alkane having 6 to 46 carbon atoms, more preferably 8 to 40 carbon atoms, even more preferably 12 to 34 carbon atoms, most preferably 1 6 to 30 carbon atoms is used as a solvent.
  • the alkane being used as a solvent is a decane, dodecane, tetradecane, hexadecane, octadecane, eicosane. docosane, hexamethyltetracosane.
  • the alkane may be linear or branched with branched alkanes such as squalene being preferred.
  • the preparation of the MSC InP is preferably achieved by a reaction mixture comprising a solvent and the solvent comprises at least one alkene, preferably an alkene having 6 to 36 carbon atoms, more preferably 8 to 30 carbon atoms, even more preferably 12 to 24 carbon atoms, most preferably 1 6 to 20 carbon atoms. More preferably, the alkene is a 1 -alkene, such as 1 -decene, 1 -dodecene, 1 - Tetradecene, 1 -hexadecene, 1 -octadecene, 1 -eicosene. 1 -docosene.
  • the alkene may be linear or branched.
  • alkenes are preferred in view of the other solvents mentioned above.
  • the preparation of the MSC InP is achieved at a temperature 1 10°C or above, more preferably 1 15°C o r above.
  • the preparation of the MSC InP is achieved at a temperature in the range of 1 10 to 180 ⁇ , more preferably 1 15 to 140 ⁇ .
  • the MSC InP exhibits an Exciton Peak of at least 370 nm, preferably at least 380 nm, in the absorbance spectrum measured at 25° using a toluene solution.
  • the MSC InP being achieved by the methods mentioned above and below and being preferably used as a starting material for the preparation of QD having the features mentioned above and below and preferably comprising a shell.
  • the QD having a shell exhibits an Exciton Peak of between 400-600nm, preferably between 440-500nm, in the absorption spectrum measured at 25°using a toluene solution.
  • the preparation method of quantum dots especially the preparation of the Magic Size Cluster MSC of InP (MSC InP) preferably comprises a quenching step, wherein the quenching step more preferably includes a lowering of the temperature of a reaction mixture by at least 130 °C, preferably at least 150°C within a period of time less than 2 seconds, preferably less than 1 second.
  • QD quantum dots
  • MSC InP Magic Size Cluster MSC of InP
  • the quenching step is performed by adding a solvent to the reaction mixture. More preferably, the solvent being added to the reaction mixture exhibits a temperature below 100 °C, more p referably below 50 °C, even more preferably below 30 °C, most preferably b elow 10 °C.
  • the temperature decrease based the temperature of the reaction mixture, the temperature of the solvent being added thereto, the volume of the reaction mixture, the volume of the solvent being added thereto and the time span during which the solvent being added to the reaction mixture.
  • the temperature of any device being in contact with the reaction mixture may have an influence to the data mentioned above, e. g. the temperature and power output of the heating mantle if used.
  • the volume ratio of the reaction mixture to the solvent being added to the reaction mixture is in the range of 4:1 to 1 :4 preferably 2:1 to 1 :2.
  • the preparation of the MSC InP is preferably achieved in the presence of a carboxylate compound, more preferably carboxylate compound having 2 to 30 carbon atoms, preferably 4 to 24 carbon atoms, even more preferably 8 to 20 carbon atoms, most preferably 10 to 26 carbon atoms.
  • the carboxylate compound is a saturated carboxylate compound.
  • the carboxylate compound could be added to the reaction mixture as a free acid or as a salt.
  • the carboxylate compound is added as a precursor, preferably an indium precursor wherein preferred indium precursors are disclosed above and below.
  • preparation of the MSC InP is preferably achieved using specific precursors, solvents, and temperatures. This means that the MSC InP are preferably obtained by these measures.
  • the obtained MSC InP can be used as starting materials for further modifying the features of the quantum dots and/or the MSC InP.
  • the MSC InP being prepared by a reaction mixture comprising a carboxylate compound in a first reaction step A) are preferably reacted with a ligand in a second reaction step B).
  • the ligand used in the second reaction step B) is a phosphonic acid, preferably an alkyl phosphonic acid having 1 to 36 carbon atoms, preferably 6 to 30 carbon atoms, even more preferably 10 to 24 carbon atoms, most preferably 12 or 20 carbon atoms in the alkyl group.
  • the phosphonic acid can also be added as a salt. In a specific embodiment, the phosphonic acid is added as an indium salt.
  • an indium salt of an alkyl phosphonic acid having 1 to 36 carbon atoms, preferably 6 to 30 carbon atoms, even more preferably 10 to 24 carbon atoms, most preferably 12 or 20 carbon atoms in the alkyl group is used for the second reaction step B), such as indium octadecylphosphonate,
  • the MSC InP being prepared by a reaction mixture comprising a carboxylate compound in a first reaction step A) are preferably purified before performing the second step B).
  • the purification is preferably performed by adding a solvent to the mixture obtained in the first reaction step A) and preferably precipitating the MSC InP.
  • the magic size clusters (MSC) obtained in a reaction step and/or any product obtained using these MSC can be purified. This purification can be done as intermediate step or to obtain a purified quantum dots according to the present invention.
  • the purification can be achieved by dispersing 0.1 to 10 equivalents of the crude solution in 1 equivalent of a solvent (by volume), preferably a hydrocarbon solvent, e.
  • a cleaning solution such as a ketone, alcohol, preferably acetone, methanol, ethanol or propanol, more preferably an ketone, e. g. acetone is preferably added to the composition.
  • the resultant suspension is preferably centrifuged for a time and at a speed sufficient for a useful precipitation. E.g. good results are achieved with 5 min at a speed of 5000 rpm.
  • the cleaning solution comprises one compound selected from one or more members of the group consisting of ketones, such as, methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, and cyclohexanone; alcohols, such as, methanol, ethanol, propanol, butanol, hexanol, cyclo hexanol, ethylene glycol; and pentane; halogenated hydrocarbons, such as chloroform;
  • ketones such as, methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, and cyclohexanone
  • alcohols such as, methanol, ethanol, propanol, butanol, hexanol, cyclo hexanol, ethylene glycol
  • pentane halogenated hydrocarbons, such as chloroform
  • the cleaning solution comprises three parts the crude solution with the QDs, the solvent and the anti-solvent.
  • the solvent is typically a non-polar compound preferably an alkane or a benzene derivative such as toluene or a halogenated hydrocarbon, more preferably toluene, chloroform, hexane and pentane.
  • the anti-solvent is typically a polar compound such as an alcohol, ester or nitrogen containing compound, preferably methanol, ethanol, isopropanol, butanol, ethyl acetate and acetonitrile.
  • the ratios of the crude, solvent and anti-solvent are in the ranges of 2.5:2.5:1 to 1 :20:80.
  • the cleaning solution comprises one or more of ketones to more effectively remove unreacted core precursors from the composition obtained in step A) and/or the composition obtained in step B) as mentioned above or any other reaction composition and remove e. g. the ligands leftovers.
  • the cleaning solution contains one or more of ketones selected from the group consisting of methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, and cyclohexanone, and one more solvent selected from halogenated hydrocarbons, preferably chloroform, acetonitrile, ethyl acetate, xylene or toluene to remove unreacted core precursors from the composition obtained in step A) and/or the composition obtained in step B) as mentioned above or any other reaction composition and remove e. g. the ligands leftovers in the solution effectively.
  • ketones selected from the group consisting of methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, and cyclohexanone
  • solvent selected from halogenated hydrocarbons, preferably chloroform, acetonitrile, ethyl acetate, xylene
  • the cleaning solution contains one or more of ketones selected from methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, and cyclohexanone, and chloroform.
  • the mixing ratio of ketones: chloroform can be 1 :2 - 20:1 in a molar ratio.
  • it is 1 :1 - 5:1 to remove unreacted core precursors from the composition obtained in step A) and/or the ligands contained in the composition obtained in step B) as mentioned above or any other reaction composition and to remove e.g. the ligands leftovers in the solution.
  • the cleaning removes the extra ligands and the unreacted precursor.
  • the MSC InP being prepared by a reaction mixture comprising a carboxylate compound in the first reaction step A) is preferably reacted with a ligand in a second reaction step B) at a high temperature.
  • the second reaction step B) is performed at a reaction temperature above 100°C, preferably at a reaction t emperature above 200°C, more preferably at a reaction temperature ab ove 300°C and even more preferably at a reaction temperature above 350 ⁇ .
  • the upper temperature limit of the second reaction step B) is given by the temperature stability of the product.
  • the second reaction step B) is performed at a reaction temperature below 500°C, preferably at a reaction temperature below 450°C, more preferably a t a reaction temperature below 400°C and even more preferably at a reaction
  • the reaction step B) could be performed in a solvent.
  • the solvents mentioned above could be used for performing the reaction step B).
  • a non-coordinating solvent is used.
  • an alkane especially a squalane having 6 to 46 carbon atoms, more preferably 8 to 40 carbon atoms, even more preferably 12 to 34 carbon atoms, most preferably 1 6 to 30 carbon atoms is used as a solvent is used as a solvent in reaction step B).
  • alkanes are most preferred solvents.
  • the second reaction step B) is preferably stopped by quenching, preferably by lowering the temperature of a reaction mixture for preparing MSC InP by at least 130 ⁇ , p referably at least 150 ⁇ within a period of time less than 2 seconds, preferably less than 1 second.
  • the second reaction step B) is stopped by adding a solvent to the reaction mixture.
  • the solvent exhibits a temperature below 100 °C, more preferably below 50 ⁇ , even more pref erably below 30 °C, most preferably below 10 °C.
  • the volume ratio of the reaction mixture of the second reaction step B) to a solvent being added to the reaction mixture of the second reaction step B) is preferably in the range of 4 to 1 preferably 2 to 1 .
  • a shell of a semiconductor is grown onto the magic size cluster comprising indium phosphide (MSC InP) and/or the quantum dots of the present invention as mentioned above and below.
  • said shell comprises group 12 and group 1 6 elements of the periodic table.
  • the shell comprises ZnS or ZnSe, more preferably ZnSe. Preferred embodiments regarding the shell are specified above and below.
  • the Magic Size Cluster MSC of InP preferably comprises a ligand, preferably a carboxylate ligand, more preferably a carboxylate ligand having 2 to 30 carbon atoms, preferably 4 to 24 carbon atoms, even more preferably 8 to 20 carbon atoms, most preferably 10 to 26 carbon atoms, even more preferably a carboxylate ligand selected from the group consisting of myristate, palmitate, laurate, stearate, oleate.
  • MSC InP are preferably used as a starting material for a preparing QD having a shell.
  • the Magic Size Cluster MSC of InP preferably comprises a ligand, preferably a phosphorus containing ligand, such as phosphine ligands, preferably alkyl phosphine ligands having 3 to 108 carbon atoms, preferably trioctylphosphine, phosphine oxide ligands, preferably alkyl phosphine oxide having 3 to 108 carbon atoms and/or phosphonate ligands, more preferably an alkyl phosphonate ligand having 1 to 36 carbon atoms, preferably 6 to 30 carbon atoms, even more preferably 10 to 24 carbon atoms, most preferably 12 or 20 carbon atoms in the alkyl group, even more preferably a ligand selected from the group consisting of
  • Trioctylphosphine oxide TOPO
  • Trioctylphosphine TOP
  • TOP Trioctylphosphine
  • TBP Tributylphosphine
  • DDPA Dodecylphosphonic acid
  • MSC InP Tetradecylphosphonic acid
  • ODPA Octadecylphosphonic acid
  • HPA Hexylphosphonic acid
  • the solvent is selected from amines, aldehydes, alcohols, ketones, ethers, esters, amides, sulfur compounds, nitro compounds, phosphorus compounds, hydrocarbons, halogenated hydro-carbons (e.g. chlorinated hydrocarbons), aromatic or heteroaromatic hydrocarbons, halogenated aromatic or heteroaromatic hydrocarbons and/or (cyclic) siloxanes, preferably cyclic hydrocarbons, terpenes, epoxides, ketones, ethers and esters.
  • a non- coordinating solvent is used.
  • an alkane more preferably a squalane is used as a solvent for achieving a shell.
  • an alkane having 6 to 46 carbon atoms, more preferably 8 to 40 carbon atoms, even more preferably 12 to 34 carbon atoms, most preferably 1 6 to 30 carbon atoms is used as a solvent.
  • the alkane being used as a solvent is a decane, dodecane, tetradecane, hexadecane, octadecane, eicosane. docosane,
  • alkane may be linear or branched with branched alkanes such as squalane being preferred.
  • the preparation of the shell is preferably achieved by a reaction mixture comprising a solvent and the solvent comprises at least one alkene, preferably an alkene having 6 to 36 carbon atoms, more preferably 8 to 30 carbon atoms, even more preferably 12 to 24 carbon atoms, most preferably 1 6 to 20 carbon atoms. More preferably, the alkene is a 1 -alkene, such as 1 -decene, 1 -dodecene, 1 - Tetradecene, 1 -hexadecene, 1 -octadecene, 1 -eicosene. 1 -docosene.
  • the alkene may be linear or branched.
  • the preparation of the shell is preferably achieved by a reaction mixture comprising a solvent and the solvent comprises at least one phosphorus compound, such as phosphine compounds, preferably alkyl phosphine compounds having 3 to 108 carbon atoms, phosphine oxide compounds, preferably alkyl phosphine oxide having 3 to 108 carbon atoms and/or phosphonate compounds, more preferably an alkyl phosphonate compounds having 1 to 36 carbon atoms, preferably 6 to 30 carbon atoms, even more preferably 10 to 24 carbon atoms, most preferably 12 or 20 carbon atoms in the alkyl group.
  • phosphorus compound such as phosphine compounds, preferably alkyl phosphine compounds having 3 to 108 carbon atoms, phosphine oxide compounds, preferably alkyl phosphine oxide having 3 to 108 carbon atoms and/or phosphonate compounds, more preferably an alkyl phosphonate compounds having 1 to 36 carbon atoms, preferably
  • Trioctylphosphine is used as a solvent for the preparation of a shell.
  • alkenes are preferred in view of the other solvents mentioned above.
  • the solvent for the preparation of the shell comprises a mixture of an alkene and a phosphorus compound.
  • the preparation of the shell is achieved at a temperature above 1 10 °C, preferably in the range of 1 10 to 400 °C, m ore preferably above 150 °C, even more preferably above 200 ⁇ and most p referably above 220°C.
  • t he preparation of the shell is preferably achieved at a temperature in the range of 100 to 400 °C, more preferably in the range of 150 to 350 °C, even more most preferably in the range of 180 to 300 °C, most preferably in t he range of 210 to
  • the shell is preferably prepared by mixing MSC InP and a first precursor and heating up the obtained mixture and then adding a second precursor, preferably the first precursor comprises an element of group 12 of the periodic table and the second precursor comprises an element of group 1 6 of the periodic table.
  • the first precursor comprises Zn
  • the second precursor comprises S, Se, preferably Se.
  • the first precursor comprises an element of group 13 of the periodic table and a the second precursor comprises an element of group 15 of the periodic table
  • the first precursor comprises In
  • the second precursor comprises P.
  • the shell is preferably prepared by mixing MSC InP and a second precursor and heating up the obtained mixture and then adding a first precursor, preferably the first precursor comprises an element of group 12 of the periodic table and the second precursor comprises an element of group 1 6 of the periodic table.
  • the first precursor comprises Zn
  • the second precursor comprises S, Se and/or the first precursor comprises an element of group 13 of the periodic table and a the second precursor comprises an element of group 15 of the periodic table
  • the first precursor comprises In
  • the second precursor comprises P.
  • the semiconductor precursor comprises a Zn compound and/or an In compound, preferably a Zn carboxylate, more preferably a zinc carboxylate having 2 to 30 carbon atoms, preferably 4 to 24 carbon atoms, even more preferably 8 to 20 carbon atoms, most preferably 10 to 26 carbon atoms, even more preferably a zinc carboxylate selected from the group consisting of Zn myristate, Zn palmitate, Zn laurate, Zn stearate, Zn oleate and/or an indium carboxylates, more preferably indium carboxylates having 2 to 30 carbon atoms, preferably 4 to 24 carbon atoms, even more preferably 8 to 20 carbon atoms, most preferably 10 to 1 6 carbon atoms even more preferably a indium carboxylate selected from the group consisting of In myristate, In palmitate, In laurate, In stearate, In oleate.
  • a Zn carboxylate more preferably a zinc carboxylate having 2 to 30
  • the semiconductor precursor comprises a S compound, preferably a sulfur solution and/or a sulfur suspension, a Se compound, preferably a Se solution and/or a Se suspension and/or an P compound, preferably an alkylsilyl phosphine more preferably
  • a sulfur solution more preferably a S solution comprising a phosphorus containing solvent, e.g. trioctylphosphine is used as a semiconductor precursor.
  • a S solution comprising a phosphorus containing solvent, e.g. trioctylphosphine is used as a semiconductor precursor.
  • a Se suspension comprising a hydrocarbon solvent, e.g. an 1 - alkene, such as 1 -octadecene and/or an organic phosphine compounds, preferably alkyl phosphine compounds having 1 to 30 carbon atoms, preferably 1 to 10 carbon atoms, even more preferably 1 to 4 carbon atoms, most preferably 1 or 2 carbon atoms in the alkyl groups or aryl phosphine compounds having 6 to 30 carbon atoms, preferably 6 to 18 carbon atoms, even more preferably 6 to 12 carbon atoms, most preferably 6 or 10 carbon atoms in the aryl groups is used as a semiconductor precursor.
  • a hydrocarbon solvent e.g. an 1 - alkene, such as 1 -octadecene and/or an organic phosphine compounds, preferably alkyl phosphine compounds having 1 to 30 carbon atoms, preferably 1 to 10 carbon atoms, even more preferably 1 to
  • an organic phosphine compound as mentioned above regarding the InP precursor e.g. tris(trimethylsilyl)phosphine and similar materials having an aryl, and/or alkyl group instead of the methyl unit, such as tris(triphenylsilyl)phosphine, tris(triethylsilyl)phosphine,
  • the MSC InP being preferably prepared by a reaction mixture comprising a alkly phosphonate compound in a first reaction step A1 ) are reacted with a semiconductor precursor in a second reaction step B1 ).
  • the second reaction step B1 ) is performed by heating up a composition comprising a first precursor, preferably Zn compound and/or an In compound, to a temperature above 50°C, preferably above 90°C and a composition compr ising the reaction product from the first reaction step A1 ) and a second precursor, preferably a S and/or a Se and/or a P compound are injected into the composition comprising a first precursor.
  • the temperature of the composition comprising the second precursor comprises a temperature above 20°C, more preferably above 50°C at the time of the injec tion to the composition comprising the first precursor.
  • the second reaction step B1 ) is performed by heating up a composition comprising a first precursor, preferably Zn compound and/or an In compound, to a temperature in the range of 50 ⁇ to 300 , preferably in the range of 90 ⁇ to 120 and a composition comprising the reaction product from the first reaction step A1 ) and a second precursor, preferably a S and/or a Se and/or a P compound are injected into the composition comprising a first precursor.
  • the composition comprising the second precursor and the reaction product from the first reaction step A1 ) is preferably heated up to a temperature in the range of 20 ⁇ to 120 , preferably in the range of 50 ⁇ to 100 before mixing.
  • the temperature of the reaction mixture is raised after the second precursor, preferably a S and/or a Se and/or a P compound is added, preferably to a temperature above 100°C, mor e preferably above 150°C, even more preferably above 200 ⁇ and most pr eferably above 220°C.
  • the temperature of the reaction mixture is raised after the second precursor, preferably a S and/or a Se and/or a P compound is added, to a temperature in the range of 100°C to 30 0°C, more preferably in the range of 150°C to 280 °C, even more preferably in the range of 200°C to 260 ⁇ and most preferably in the range of above 220 ⁇ to 240 .
  • the second reaction step B1 ) is performed by heating up a composition comprising a second precursor, preferably a S and/or a Se and/or a P compound, to a temperature above 50°C, preferably above 90°C and a composition compr ising the reaction product from the first reaction step A1 ) and a first precursor, preferably Zn compound and/or an In compound, is injected into the composition comprising a second precursor.
  • a first precursor preferably Zn compound and/or an In compound
  • the temperature of the composition comprising the first precursor comprises a temperature above 20°C, more preferably above 50°C at the time of the injection to the composition comprising the second precursor.
  • the second reaction step B1 ) is performed by heating up a composition comprising a second precursor, preferably a S and/or a Se and/or a P compound, to a temperature in the range of 50 ⁇ to 300 , preferably in the range of 90 ⁇ to 120 and a composition comprising the reaction product from the first reaction step A1 ) and a first precursor, preferably Zn compound and/or an In compound, is injected into the composition comprising a second precursor.
  • the composition comprising the first precursor is preferably heated up to a temperature in the range of 20°C to 120 °C, prefera bly in the range of 50°C to 100°C before mixing.
  • the temperature of the reaction mixture is raised after the composition comprising first precursor, preferably Zn compound and/or an In compound, is added, preferably to a temperature above 100°C, more preferably above 150 ⁇ , even more preferably above 200°C and most preferably above 220 ⁇ .
  • the temperature of the reaction mixture is raised after the composition comprising first precursor, preferably Zn compound and/or an In compound, is added, preferably to a temperature in the range of 100°C to 300°C, more preferably in the range of 150°C to 280 ⁇ , even more preferably in the range of 200 ⁇ to 260 ⁇ and most preferably in the range of above 220 ⁇ to 240 ⁇ .
  • the reaction product of the first reaction step A1 ) can be purified before performing the second reaction step B1 ) for preparing a shell.
  • the purification is performed by adding a solvent and anti-solvent to the mixture obtained in the first reaction step A1 ) and preferably precipitating the MSC InP.
  • a mixture of the cleaned reaction product of Step A1 ) and a first precursor, preferably a Zn compound and/or an In compound are preferably mixed and heated to a temperature above 50°C, preferably above 90°C and thereafter a composition comprising a second precursor, preferably a S compound, a Se compound and/or an P compound is added.
  • the second reaction step B1 ) is stopped by lowering the temperature to room temperature.
  • the second reaction step B1 ) is stopped by quenching, preferably by lowering the temperature of a reaction mixture for preparing MSC InP by at least 130 °C, preferably at least 150°C within a pe od of time less than 2 seconds, preferably less than 1 second.
  • the quenching especially the adding of a solvent and the temperature of the solvent added are provided above and added by reference thereto.
  • the present invention also relates to a method for preparing quantum dots comprising a core / shell structure, wherein the method comprises following steps (a), (b) and (c) in this sequence. (a) synthesis of a core in a solution,
  • step (c) coating the core with at least one shell layer using said solution obtained in step (b).
  • the present invention further relates to a composition comprising or consisting of the QD of the present invention, preferably semiconducting light emitting nanoparticle of the present invention and at least one additional material, preferably the additional material is selected from the group consisting of organic light emitting materials, inorganic light emitting materials, charge transporting materials, scattering particles, host materials, and matrix materials.
  • a further embodiment of the present invention is a formulation comprising or consisting of the QD of the present invention, preferably semiconducting light emitting nanoparticle of the present invention and at least one solvent. Preferred solvents are mentioned above and below.
  • the present invention further relates to the use of the QD of the present invention, preferably semiconducting light emitting
  • nanoparticle of the present invention the composition of the present invention or the formulation of the present invention in an electronic device, optical device or in a biomedical device.
  • QD quantum dots
  • the present invention further relates to an optical medium comprising the nanosized light emitting material.
  • the optical medium can be an optical sheet, for example, a color filter, color conversion film, remote phosphor tape, or another film or filter.
  • sheet includes film and / or layer like structured mediums.
  • the invention further relates to an optical device comprising the optical medium.
  • the optical device can be a liquid crystal display device (LCD), Organic Light Emitting Diode (OLED), backlight unit for an optical display, Light Emitting Diode device (LED), Micro Electro Mechanical Systems (here in after "MEMS”), electro wetting display, or an electrophoretic display, a lighting device, and / or a solar cell.
  • LCD liquid crystal display device
  • OLED Organic Light Emitting Diode
  • LED Light Emitting Diode device
  • MEMS Micro Electro Mechanical Systems
  • electro wetting display or an electrophoretic display
  • a lighting device and / or a solar cell.
  • Embodiment 1 Quantum Dots (QD) based on Indium Phosphide (InP) characterized in that the QD exhibit a ratio of the optical density of the first exciton peak maximum to the optical density of the trough on the high energy side of the first exciton peak of above 1 .80 and below 2.5 in the absorption spectrum measured at 25°using a toluene solution, preferably the QD comprise centre area of InP, more preferably the centre area of InP comprises a diameter in the range of 0.8 to 5.0 nm, preferably 0.9 nm to 3.0 nm, more preferably 1 .0 to 1 .5 nm.
  • Embodiment 2 QD according to embodiment 1 , characterized in that the QD are based on magic sized clusters comprising indium phosphide, more preferably the QD are based on magic sized clusters essentially consisting of indium phosphide (MSC InP).
  • MSC InP indium phosphide
  • Embodiment 3 QD according to embodiment 1 or 2, characterized in that QD are based on a nanocrystal core, which consists solely of fused 6- membered rings with all phosphorus atoms coordinated to four indium atoms in a pseudo-tetrahedral arrangement, preferably the nanocrystal core have the formula [ln 2 i P2o] 3+ , [ln 2 P4o] 6+ , [I nesPeo] 9 *, [ln 8 4Pso] 12+ , [ln 95 P9o] 15+ , [lnsi P 30 ] 3+ , [ln 4 i P 0 ] 3+ , [ln 5 i P 5 o] 3+ , [ln 6 i P 6 o] 3+ , [ln 7 i P7o] 3+ , [ln 8 i Pso] 3+ , and/or [ ⁇ ⁇ 91 P 90 ] 3+ .
  • Embodiment 4 QD according to any one of embodiments 1 to 3,
  • the QD exhibit a ratio of the peak maximum to the peak minimum of above 1 .80 and below 2.5 in the absorption spectrum at a wavelength in the range of 400 to 500 nm measured at 25°using a toluene solution.
  • Embodiment 5 QD according to any one of embodiments 1 to 4,
  • the QD comprise a shell of a semiconductor.
  • Embodiment 6 Method for preparing QD being based on InP, characterized by preparing Magic Size Cluster MSC of InP (MSC InP).
  • Embodiment 7 Method for preparing QD according to embodiment 6, characterized in that the MSC InP exhibits an Exciton Peak of at least 370 nm, preferably at least 380 nm, in the absorbance spectrum measured at 25°using a toluene solution.
  • Embodiment 8 Method for preparing QD according to embodiment 6 or 7, characterized in that a shell of a semiconductor is grown onto the MSC InP.
  • Embodiment 9 Method for preparing QD according to embodiment 8, characterized in that the shell comprises InP, ZnS or ZnSe, preferably ZnSe, or the shell comprises a mixture of ZnS and ZnSe.
  • Embodiment 10 Method for preparing QD according to any one of embodiments 8 or 9, characterized in that the preparation of the shell is achieved by a reaction mixture comprising a solvent and the solvent comprises at least one alkene, preferably an alkene having 6 to 36 carbon atoms, more preferably 8 to 30 carbon atoms, even more preferably 12 to 24 carbon atoms, most preferably 1 6 to 20 carbon atoms.
  • a reaction mixture comprising a solvent and the solvent comprises at least one alkene, preferably an alkene having 6 to 36 carbon atoms, more preferably 8 to 30 carbon atoms, even more preferably 12 to 24 carbon atoms, most preferably 1 6 to 20 carbon atoms.
  • Embodiment 1 1 Method for preparing QD according to embodiment 10, characterized in that the alkene is a 1 -alkene.
  • Embodiment 12 Method for preparing QD according to any one of embodiments 6 to 1 1 , characterized in that the preparation of the shell is achieved at a temperature above 1 10 °C, preferably in the range of 1 10 to 400 °C, more preferably above 150 ⁇ , even more pre ferably in the range of 150 to 300 ⁇ , most preferably in the range of 1 80 to 250 ⁇ .
  • Embodiment 13 Method for preparing QD according to any one of embodiments 6 to 12, characterized in that the MSC InP are prepared by a reaction mixture comprising a alkly phosphonate compound and/or alkyl phosphonic acid compound in a first reaction step A1 ) and the MSC InP obtained are reacted with a semiconductor precursor in a second reaction step B1 ).
  • Embodiment 14 Method for preparing QD according to embodiment 13, characterized in that the characterized in that the semiconductor precursor comprises a Zn compound and/or an In compound, preferably a Zn carboxylate, more preferably a zinc carboxylate having 2 to 30 carbon atoms, preferably 4 to 24 carbon atoms, even more preferably 8 to 20 carbon atoms, most preferably 10 to 26 carbon atoms, even more preferably a carboxylate ligand selected from the group consisting of myristate, palmitate, laurate, stearate, oleate and/or an indium
  • carboxylates more preferably indium carboxylates having 2 to 30 carbon atoms, preferably 4 to 24 carbon atoms, even more preferably 8 to 20 carbon atoms, most preferably 10 to 1 6 carbon atoms.
  • Embodiment 15 Method for preparing QD according to embodiment 13 or 14, characterized in that the MSC InP being preferably prepared by a reaction mixture comprising a phosphonate compound and/or alkly phosphonic acid compound in a first reaction step A1 ) are purified before performing the second step B1 ).
  • Embodiment 1 6 Method for preparing QD according to any one of embodiments 13 to 15, characterized in that for performing the second step B1 ) a mixture of the reaction product of the first step A1 ) and a first precursor, preferably a Zn compound and/or an In compound are mixed and heated to a temperature above 50°C, preferably above 90°C and thereafter a composition comprising a second precursor, preferably a S compound, a Se compound and/or an P compound is added.
  • a first precursor preferably a Zn compound and/or an In compound
  • Embodiment 17 QD obtainable by a method according to any one of embodiments 6 to 1 6.
  • Embodiment 18 Composition comprising QD according to any one of embodiments 1 to 5 and 17, and at least one additional material, preferably the additional material is selected from the group consisting of organic light emitting materials, inorganic light emitting materials, charge transporting materials, scattering particles, host materials, and matrix materials.
  • Embodiment 19 Formulation comprising or consisting of the QD according to any one of embodiments 1 to 5 and 17 or the composition according to embodiment 18, and at least one solvent.
  • Embodiment 20 Use of the QD according to any one of claims according to any one of embodiments 1 to 5 and 17, or the composition according to embodiment 18, or the formulation according to embodiment 19 in an electronic device, optical device or in a biomedical device.
  • Embodiment 21 An optical medium comprising the QD according to any one of embodiments 1 to 5 and 17 or the composition according to claim 18.
  • Embodiment 22 An optical device comprising the optical medium according to embodiment 21 .
  • semiconductor means a material which has electrical
  • organic means any material containing carbon atoms or any compound that containing carbon atoms ionically bound to other atoms such as carbon monoxide, carbon dioxide, carbonates, cyanides, cyanates, carbides, and thiocyanates.
  • emission means the emission of electromagnetic waves by electron transitions in atoms and molecules.
  • quantum dots according to the invention and the optical media and/or the optical devices, obtainable therefrom are distinguished over the prior art by any one of the following surprising advantages:
  • optical media and/or the optical devices obtainable using the
  • quantum dots according to the invention exhibit very high stability and a very long lifetime compared with optical media and/or optical devices obtained using conventional quantum dots.
  • the quantum dots according to the invention can be processed using conventional methods, so that cost advantages can also be achieved thereby. 3.
  • the quantum dots according to the invention are not subject to any particular restrictions, enabling the workability of the present invention to be employed comprehensively.
  • the quantum dots according to the invention provide a high color purity and a low FWHM.
  • the quantum dots according to the invention can be produced in a very rapid and easy manner using conventional methods, so that cost advantages can also be achieved thereby.
  • the quantum dots according to the invention are less toxic than conventional formulations and have a high environmental condition
  • the quantum dots according to the invention show a high emission in the visual range of the electromagnetic radiation.
  • the quantum dots according to the invention show a high absorption.
  • the flask After UV-vis confirmed formation of MSCs, the flask is cooled and then carefully evacuated until all of the toluene is removed. The flask is transferred into a nitrogen filled glovebox. The crude MSCs are
  • octadecylphosphonic acid are weighed out into a 50ml 14/20 3-neck round- bottom flask equipped with a stir bar, thermowell, reflux condenser, and septum. Dry squalane (5ml) is quickly injected into the 3-neck flask.
  • the apparatus is evacuated and raised in temperature to 120 °C.
  • the solution is allowed to off-gas acetic acid under reduced pressure to generate the indium octadecylphosphonate solution for approximately 12 h at 120 °C. After this the flask is filled with nitr ogen, the temperature raised to 300 °C for a couple of minutes to form a clear, homogeneous solution, and finally the solution is cooled back to 120 ⁇ C a nd evacuated for another 2 h degassing step.
  • a solution of 0.2g of purified InP MA MSCs in 2.5ml of squalane is prepared and drawn up into a plastic syringe and stoppered.
  • the 3-neck flask is then filled with nitrogen and rapidly heated by setting the temperature controller to the maximum setting (450 °C).
  • the InP MA MSCs solution is injected into the indium octadecylphosphonate solution when the temperature controller read 100 °C as the temperature of the solution is rising. Aliquots are taken during the reaction taking note of the time after injection and the temperature of the flask. Once the reaction solution reached a temperature of 350 °C, the tempe rature controller is set to 370 ⁇ C for further growth.
  • the hexane is distilled off by heating under reduced pressure and then the temperature is raised to around 200°C to distill off the squalane.
  • the flask is heated to 150 ° C and held under vacuum for 1 hour when the pressure stabilized.
  • the system is filled with argon and heated to 300 ° C. After boiling it is cooled to 100 ° C and pumped again.
  • the system is filled with argon again and heated to 320 ° C. Once the solution is clear it is cooled to 150 ° C and the formed water is removed by putting the system under reduced pressure, 100 mtorr. 6. Once the pressure stabilized, the flask is cooled to room temperature and stored; in inert conditions.
  • the precipitant is dissolved in 1 .5 ml toluene and 4.5 ml ODE.
  • the quantum dots show a peak emission at 452nm and an optical density of the first exciton peak maximum to the optical density of the trough on the high energy side of the first exciton peak of 1 .85 using the methods mentioned above.

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Abstract

La présente invention concerne des points quantiques (QD) ayant une absorption élevée, un procédé de préparation desdits points quantiques, un support optique et un dispositif optique.
PCT/EP2018/078839 2017-10-24 2018-10-22 Points quantiques ayant une absorption élevée WO2019081401A1 (fr)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020099284A1 (fr) * 2018-11-14 2020-05-22 Merck Patent Gmbh Nanoparticule
CN111290162A (zh) * 2020-03-27 2020-06-16 Tcl华星光电技术有限公司 量子点材料结构、液晶显示装置、电子设备
CN114891508A (zh) * 2022-05-07 2022-08-12 河南大学 一种兼具有高亮度和稳定性的水溶性InP核壳量子点及其合成方法和应用

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012059931A1 (fr) 2010-11-05 2012-05-10 Yissum Research Development Company Of The Hebrew University Of Jerusalem Ltd. Systèmes d'éclairage à polarisation
US8679543B2 (en) 2008-07-02 2014-03-25 Joseph Bartel Stable indium-containing semiconductor nanocrystals
US20150083969A1 (en) 2013-09-26 2015-03-26 Samsung Electronics Co., Ltd. Nanocrystal particles and processes for synthesizing the same
WO2016146719A1 (fr) 2015-03-19 2016-09-22 Universiteit Gent Synthèse de nanoparticules à taille modulable

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8679543B2 (en) 2008-07-02 2014-03-25 Joseph Bartel Stable indium-containing semiconductor nanocrystals
WO2012059931A1 (fr) 2010-11-05 2012-05-10 Yissum Research Development Company Of The Hebrew University Of Jerusalem Ltd. Systèmes d'éclairage à polarisation
US20150083969A1 (en) 2013-09-26 2015-03-26 Samsung Electronics Co., Ltd. Nanocrystal particles and processes for synthesizing the same
WO2016146719A1 (fr) 2015-03-19 2016-09-22 Universiteit Gent Synthèse de nanoparticules à taille modulable

Non-Patent Citations (8)

* Cited by examiner, † Cited by third party
Title
ARUN NARAYANASWAMY ET AL: "Temperature Dependence of the Photoluminescence of InP/ZnS Quantum Dots", JOURNAL OF PHYSICAL CHEMISTRY C,, vol. 112, no. 17, 1 May 2008 (2008-05-01), pages 6775 - 6780, XP008141473, ISSN: 1932-7447, [retrieved on 20080410], DOI: 10.1021/JP800339M *
CHEM. MATER., vol. 27, 2015, pages 1432 - 1441
D. GARY ET AL., CHEMCOMM, 2016, pages 161
D. GARY ET AL., JACS, vol. 138, 2016, pages 1510 - 1513
D.GARY ET AL., CHEM. MATER., vol. 27, 2015, pages 1432 - 1441
DYLAN C. GARY ET AL: "Two-Step Nucleation and Growth of InP Quantum Dots via Magic-Sized Cluster Intermediates", CHEMISTRY OF MATERIALS, vol. 27, no. 4, 10 February 2015 (2015-02-10), pages 1432 - 1441, XP055462428, ISSN: 0897-4756, DOI: 10.1021/acs.chemmater.5b00286 *
J. AM. CHEM. SOC., vol. 138, 2016, pages 1510 - 1513
J. NING; U. BANIN, CHEMCOMM, vol. 53, 2017, pages 2626 - 2629

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020099284A1 (fr) * 2018-11-14 2020-05-22 Merck Patent Gmbh Nanoparticule
CN111290162A (zh) * 2020-03-27 2020-06-16 Tcl华星光电技术有限公司 量子点材料结构、液晶显示装置、电子设备
CN111290162B (zh) * 2020-03-27 2021-05-28 Tcl华星光电技术有限公司 液晶显示装置、电子设备
US11520180B2 (en) 2020-03-27 2022-12-06 Tcl China Star Optoelectronics Technology Co., Ltd. Quantum dot material structure, liquid crystal display device, and electronic device
CN114891508A (zh) * 2022-05-07 2022-08-12 河南大学 一种兼具有高亮度和稳定性的水溶性InP核壳量子点及其合成方法和应用
CN114891508B (zh) * 2022-05-07 2023-03-03 河南大学 一种兼具有高亮度和稳定性的水溶性InP核壳量子点及其合成方法和应用

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