111 results about "Intersystem crossing" patented technology

Organic light emitting devices are described wherein the emissive layer comprises a host material containing a fluorescent or phosphorescent emissive molecule, which molecule is adapted to luminesce when a voltage is applied across the heterostructure, wherein an intersystem crossing molecule of optical absorption spectrum matched to the emission spectrum of the emissive molecule enhances emission efficiency.

The invention relates to a thermal activation delayed fluorescent material with a general formula of the structure shown as the formula (I) or the formula (II). D is one of phenoxazinyl, phenothizainyl, 9,9-dimethyl acridine, 9-methyl phenazinyl, 9-phenyl phenazinyl, 4-phenoxazinyl-1-phenyl, 4-phenothizainyl-1-phenyl, 4-(9,9-dimethyl)acridinyl-1-phenyl, 4-(9-methyl)-phenazinyl-1-phenyl, 4-(9-phenyl)phenazinyl-1-phenyl and 3,5-bis-carbazolyl-1-phenyl. The invention further relates to an organic electroluminescent device which comprises a light-emitting layer, and luminescent dye of the light-emitting layer is the thermal activation delayed fluorescent material. The singlet state-triplet state energy gap (delta EST) of the thermal activation delayed fluorescent material is very small, triplet state excitors can be converted into singlet state excitors through inverse intersystem crossing (RIST) to emit light, and the efficiency and stability of an OLED device can be improved. The formula is shown in the description.

The invention discloses a thermal activation delayed fluorescence high-molecular compound which is prepared by using asymmetric thermal activation delayed fluorescence micromolecules as luminescent monomer and applying a Suzuki polymerization method. A strategy of connecting TADF micromolecules through a side chain is adopted, and polyspirofluorene, fluorene, carbazole, benzene or triphenylamine is used as a main chain, so that high triplet-state energy level of the main chain is guaranteed, the main chain can be ensured to have good hole transmission performance, prepared TADF high molecules can well inherit TADF characteristics of the micromolecules, and photoluminescence quantum yield and inverse intersystem crossing constant of certain high molecules are even higher than those of the micromolecules. The synthetic high-molecular compound has quite high glass transition temperature and thermal decomposition temperature and has quite good film-forming performance. When the high-molecular compound is applied in electroluminescent devices, highest current efficiency (38.6 cd/A), power efficiency (14.3 lm/W) and external quantum efficiency (16.1%) of current delayed fluorescence high molecules can be acquired by doping a main body and assistant TADF micromolecules.

The invention discloses a luminescent material of red-phosphorescence cuprous iodide complex and a preparation method thereof. The phosphorescence complex is obtained through complexation of CuI and a ligand, with a molecular structure of (CuIL)n, wherein L is the ligand, the ligand is electrically neutral heterocyclic ligand 4-(2-benzoxazolyl) pyridine, that is, the combination of the benzoxazolyl and the pyridine. Due to introducing the benzoxazolyl group beneficial to luminescence of molecular excited state and heavy halogen iodine beneficial to intersystem crossing of the excited state into the material, and promotion of the intersystem crossing by metal-to-ligand charge transfer, the material has relatively good phosphorescence performance. The material is obtained by the directly mixing reaction of the ligand with an acetonitrile solution of CuI, has advantages of simple technology, simple equipment, easily-available raw materials, low cost and good thermal stability, and can be used as a photoluminescence red-phosphorescence material, and a phosphorescent material of a luminous layer of an electroluminescent device composed of multilayer organic materials.

There is provided an organic light emitting device to break through the limit of 25% of internal quantum efficiency and 5% of external quantum efficiency while using singlet luminescence. Specifically provided is an organic light emitting device comprising an anode, an organic layer and a cathode, wherein light-emitting molecules present in an emissive layer which is at least a part of the organic layer and responsible for luminescence by charge injection effect transition from a triplet excited state having an energy level higher than a lowest excited singlet state to a singlet excited state and effect fluorescent emission in a fluorescence quantum yield of 60% or more in the same state as existing in the emissive layer, and wherein the emissive layer comprises the light-emitting molecules as a main component in an amount of 50 wt % or more, or is doped with the light-emitting molecules at a high concentration of 7 wt % or more, or is a layer in which the light-emitting molecules are excitable by direct trapping of electrons and holes has enabled to break through the limit of 25% of internal quantum efficiency and 5% of external quantum efficiency while using singlet luminescence.

The invention discloses an organic electroluminescence device. In a luminescent layer, a host material, an auxiliary host material and a fluorescent dye are contained; the host material is an exciplexformed by mixing an electron donor material and an electron acceptor material, the auxiliary host material is a thermally activated delayed fluorescent material, and a singlet-state energy level anda triplet-state energy level of the exciplex are respectively higher than those of the auxiliary host material. The organic electroluminescence device disclosed by the invention takes the exciplex with a narrow band gap as the host material, and the host material is codoped with a dye and an auxiliary host material with small DeltaEST, so that reverse intersystem crossing of the host material andthe auxiliary host material from a triplet-state excition to a singlet-state excition can be promoted, energy transmission is enhanced, quenching of the triplet-state excition is reduced, roll-off ofthe efficiency of the device is less, and the external quantum efficiency is high.

The invention discloses preparation of an interruption conjugation-based donor/acceptor type intramolecular exciplex light-emitting material and application thereof in preparation of an Organic Light-Emitting Diode (OLEDs) Device, and belongs to the technical field of organic electroluminescence. Specifically, sp3-hybridized atoms such as C, O, S and Si are used as bridging groups for interruptionconjugation; a donor and an acceptor are connected in an interruption conjugation manner; moreover, a proper donor and a proper acceptor are selected; a charge transfer excited state between the donor and the acceptor is adjusted as a lowest excited state of the whole molecule. Therefore, a hole wave function of a formed exciton is locally defined on the donor, and an electron wave function is locally defined on the acceptor; the hole and electron wave functions are completely separated in space. Therefore, the formed exciton is low in binding energy and favorable for spin flip of excited electrons, and has a reversed intersystem crossing from a triplet state to a singlet state to realize effective utilization of the triplet state by a fluorescent material. Through reasonable donor and acceptor cooperation, the interruption conjugation-based donor/acceptor type intramolecular exciplex light-emitting material also can realize red, green and blue full-color light emission.

A maser assembly includes a pump light source; a maser material including molecules that are excited through the absorption of light (1) from the pump light source, and which subsequently transfer via intersystem crossing (9) into the sublevels of their triplet ground states, so causing a population inversion between two sublevels (16,18); an electromagnetic structure in which the masing material is disposed, and which supports a microwave mode that is both resonant in frequency with and magnetically coupled to the transition between these two sublevels; and where energy is supplied to the microwave mode through stimulated emission (25) across the transition at such a rate as to exceed the mode's electromagnetic losses, the microwave mode being a maser mode. The assembly includes provisions for effecting substantially continuous maser activity during operation of the assembly. The laser crystal may be a (perdeuterated) pentacene in p-terphenyl which is held at room temperature without an additional magnetic field and the dye molecules in the single crystal may be pumped by blue LED with a frequency conversion to the yellow and green with the help of a Ce:YAG fluorescent pump light concentrator.

The invention relates to a thermally activated delayed fluorescence compound, a preparation method thereof and an organic light emitting diode device. The structural general formula of the thermally activated delayed fluorescence compound is shown in formula I as shown in specification, and R shows a chemical group as an electron donor. Trifluoromethyl (-CF3) serves as a strong electron donor group, the electron donor group is changed by matching different functional groups, influences of the intensity of the electron donor to properties of a material are researched, and the sky blue thermallyactivated delayed fluorescence compound with remarkable TADF characteristic is designed. The thermally activated delayed fluorescence compound is a sky blue TADF compound with ultra-fast reverse intersystem crossing rate and high luminous efficiency, therefore, when the thermally activated delayed fluorescence compound as a luminous material is applied to the organic light emitting diode device,the luminous efficiency of the organic light emitting diode device can be improved effectively, and the organic light emitting diode device based on the thermally activated delayed fluorescence compound has quite high device efficiency.

The invention belongs to the fields of preparation and application sciences of organic photoelectric materials and specifically relates to a luminescent material with thermotropic delayed fluorescence, an application of the luminescent material and an electroluminescent device. The luminescent material with thermotropic delayed fluorescence, provided by the invention takes a carbazole derivative as a donor group, and a relatively small tripletenergy gap is achieved by molecular distortion, so that the reverse intersystem crossing from triplet excisions to singlet excisions is realized, and theutilization ratio of the excisions and the efficiency of the device are increased. By taking the luminescent material with thermotropic delayed fluorescence, provided by the invention, as a main luminescent material, the efficiency roll-off of the device can be reduced; and serving as an object luminescent material, the luminescent material with thermotropic delayed fluorescence is high in luminescent layer brightness, good in stability, high in luminescent efficiency and long in service life. If the luminescent material with thermotropic delayed fluorescence is used as an organic luminescentmedium, the device is reduced in efficiency roll-off, high in luminescent efficiency and long in service life.

The invention relates to the technical field of organic synthetic chemistry, in particular to a 2,6-diiodo-BODIPY derivative and a preparation method and application thereof. A compound (III) can react with various nano materials (such as a metal organic framework material, a covalent organic framework material and the like) to achieve the surface modification of the nano materials and impart newfunctions to the nano materials; in addition, the intersystem crossing efficiency of the molecules of the compound is greatly increased, so that the photodynamic performance of BODIPY is greatly improved, and the compound (III) has good characteristics of being expanded and modified easily. The 2,6-diiodo-BODIPY derivative and the preparation method and application thereof have the advantages thatan effective reducing agent is selected, and a corresponding reaction condition is set, so that the compound (III) can be obtained through the reaction of a compound (II), and the yield reaches up to42%. The invention also provides the application of the compound (III) in the nano material modification.

The invention provides an organic compound with a specific structure. The organic compound is characterized by being shown as a general formula (I): the formula (I) is shown in the description; in theformula (I), X1 to X8 are respectively independently selected from CR1 or N respectively, wherein at least one is an N atom; L is a single bond and is C5 to C12 substituted or unsubstituted arylene and heteroarylene; R1 is selected from hydrogen, C1 to C10 aryl or cycloalkyl, C6 to C15 aryl or C6 to C19 condensed ring aryl and at least one is azacarbazole; Ar is substituted or unsubstituted N heterophenyl. The invention discloses an inverse intersystem crossing constant and emission delayed fluorescence rule and the designed compound is used for an organic electroluminescent device, can be used for effectively improving the current efficiency and is an organic electroluminescent material with good performance. The invention also provides the organic electroluminescent device adopting thecompound shown as the general formula.

Provided is a cyclometalated transition metal complex represented by Formula 1:

The cyclometalated transition metal complex contains a new ancillary ligand having a carboxylate acid or the like connected to a hetero ring, so that it can efficiently emit red light from a phosphorous material through intersystem crossing (ISC) to form triplet excitons and then metal to ligand charge transfer (MLCT). An organic light emitting device manufactured using the transition metal complex shows excellent luminous efficiency and external quantum efficiency.

The invention provides a pure organic room-temperature phosphorescent material with a structure as shown in formula (I) or formula (II), and also provides a preparation method for the pure organic room-temperature phosphorescent material with the structure as shown in formula (I) or formula (II). The invention discloses a series of pure organic room-temperature phosphorescent materials based on a naphthalimide derivative. The pure organic room-temperature phosphorescent materials are characterized in that pure organic electron-donating groups are introduced into molecules, so that the molecules are excited by an outside light source to generate a charge transfer state (ICT) in the molecules, and ICT can promote intersystem crossing, so that generation of room-temperature phosphorescence is facilitated. The pure organic phosphorescent material provided by the invention has the advantages of being simple and convenient to synthesize, low in cost, easy to chemically modify, low in toxicity, environmentally friendly and the like.

The invention belongs to the field of display technologies and particularly discloses an organic electroluminescent device. The organic electroluminescent device comprises a light-emitting layer, wherein the light-emitting layer comprises an exciplex consisting of donor molecules and receptor molecules and a broad-band-gap material used for increasing the spacing between the donor molecules and the receptor molecules. Through the organic electroluminescent device, the HOMO and LUMO track overlapping degree of the formed exciplex can be lowered, singlet-triplet energy level difference is reduced, the reverse intersystem crossing rate (kRISC) of an exciplex body is increased, energy transmission to guest molecules is enhanced, and the efficiency of the device is improved; and meanwhile, by introducing the broad-band-gap material, the concentration of triplet excitons in the light-emitting layer can be effectively lowered, triplet-triplet annihilation (TTA) and triplet-polaron annihilation (TPA) are suppressed, efficiency roll-off is lowered, and the life of the device is prolonged.

The invention discloses an electron donor-acceptor D-A type light-emitting small molecule containing acridine and phenanthroimidazole and application thereof in an electroluminescent device. An acridine electron donor unit and a phenanthroimidazole electron acceptor unit are respectively connected to two sides of an anthracene unit with large steric hindrance, the donor unit and the acceptor unitin the constructed molecule have large torsion angles, charge transfer with moderate intensity is realized, a hybrid local charge transfer (HLCT) excited state is further formed, high-energy triplet-state to singlet-state inverse intersystem crossing can be realized, and 100% utilization of exciton is realized. In addition, acridine and phenanthroimidazole have the characteristics of wide band gap, high fluorescence quantum yield and high carrier mobility, and the light-emitting small molecule containing acridine and phenanthroimidazole can be used for preparing a high-efficiency blue organiclight-emitting device.

The invention discloses a D-A-type polymer containing S,S-dioxy-dibenzothiophene in a main chain as well as a preparation method and application thereof. An electricity-absorbing S,S-dioxy-dibenzothiophene unit and a power supply unit are adopted to copolymerize to form a D-A structure molecule, and obtain the D-A-type polymer containing S,S-dioxy-dibenzothiophene in the main chain. The 2,8-carbonatoms of the S,S-dioxy-dibenzothiophene unit are connected with a nitrogen-containing aromatic heterocyclic unit of the power supply through a C-N bond, and a twist angle of a D-A unit is larger andis beneficial to reduce degree of conjugation of polymer molecules, effective separation of HOMO and LUMO electron clouds is achieved, singlet state-triplet state energy level difference is reduced, promotion of intermolecular inversion intersystem crossing is improved, and ratio of singlet exciton generation is increased, and device efficiency is improved. The D-A-type polymer containing S,S-dioxy-dibenzothiophene in the main chain has good solubility and can be used for preparing a light emitting layer of a polymer light emitting diode.

The invention relates to a thermally-activated delayed fluorescent material, a preparation method thereof, and an organic light-emitting diode device. The structural general formula of the thermally-activated delayed fluorescent material is represented by formula 1 shown in the description; and R in the formula 1 represents a chemical group used as an electron donor. A strong electron-withdrawinggroup with a large conjugate plane, which is used as an electron acceptor, is combined with a strong electron donor to design the dark red thermally-activated delayed fluorescent material with remarkable TADF characteristics and a low energy level. The thermally-activated delayed fluorescent material is the dark red TADF material with a low single-triplet state energy level difference, an ultrafast reverse intersystem crossing rate and a high luminous efficiency, and can effectively improve the luminous efficiency of the organic light-emitting diode device when applied to the organic light-emitting diode device as a luminescent material, and the organic light-emitting diode device based on the thermally-activated delayed fluorescent material has a very high device efficiency.

The present invention provides a thermally-activated delayed fluorescent compound. The thermally-activated delayed fluorescent compound comprises a donor unit D and an acceptor unit A, and the structural general formula is Dn-A (n = 1 or 2 or 3), wherein the molecular structure of the donor unit D comprises a diphenylamino molecular structure, and the molecular structure of the acceptor unit A comprises a trimeric dioxobenzothiophene molecular structure. The novel structure between the donor and the acceptor of the thermally-activated delayed fluorescent compound makes the compound molecule have a high intersystem crossing rate constant and an inverse intersystem crossing rate constant, so the decrease of the radiation transition rate due to the energy gap rule is effectively inhibited, thereby a high PLQY is obtained, and the application of a deep red light TADF compound material with a high-efficiency and weak roll-off in electroluminescent devices is achieved.

The invention relates to a thermally-activated delayed fluorescent material, a preparation method thereof, and an organic light-emitting diode device. The structural general formula of the thermally-activated delayed fluorescent material is represented by formula 1 shown in the description; and in the formula 1, R represents a chemical group used as an electron donor, the R is located at the firstposition, the third position, the fourth position or the fifth position of a pyridyl group, and X is one of formulas also shown in the description. The thermally-activated delayed fluorescent material has an ultrafast reverse intersystem crossing rate and a high luminous efficiency, is a blue-green light TADF material having remarkable TADF characteristics, and can effectively improve the luminous efficiency of the organic light-emitting diode device when applied to the organic light-emitting diode device as a luminescent layer material, and the organic light-emitting diode device based on the thermally-activated delayed fluorescent material has a very high device efficiency.