37 results about "Excited singlet" patented technology

The invention relates to neutral mononuclear copper (I) complexes for emitting light and with a structure according to formula (A) in which: M represents: Cu(I); L∩L represents: a single, negatively charged, bidentate ligand; N∩N represents: a diimine ligand (substituted with R and FG), in particular a substituted 2,2′-bipyridine derivative (bpy) or a substituted 1,10-phenanthroline derivative (phen); R represents: at least one sterically demanding substituent for preventing the planarisation of the complex in the excited state; FG=functional group, and represents: at least one second substituent for increasing solubility in organic solvents. The substituent can also be used for electron transport or alternatively for hole transport, said functional group being bound to the diimine ligands either directly or by means of suitable bridges; and the copper (I) complex: having a ΔE(S₁−T₁) value of less than 2500 cm⁻¹ between the lowest excited singlet state (S₁) and the triplet state (T₁) which lies below; having an emission lifespan of at most 20 μs; having an emission quantum yield of greater than 40%, and a solubility of at least 1 g/L in organic solvents, in particular polar organic hydrocarbons such as acetone, methyl ethyl ketone, benzene, toluene, chlorobenzene, dichlorobenzene, dichloromethane, chloroform, dichloroethane, tetrachloroethylene, alcohols, acetonitrile or water.

The present disclosure relates to the field of organic optoelectronics. More particularly, the present disclosure relates to photovoltaic structures and to methods to produce the same. One aspect of the disclosure is a photovoltaic structure comprising:

• • an electron acceptor material, and
  • an electron donor material, wherein the electron donor material comprises:
    • a host material, and
    • a guest material,

wherein the energy of the lowest excited singlet state of the guest is smaller than the energy of lowest excited singlet state of the host, wherein the fluorescence emission spectrum of the host overlaps with at least part of the absorption spectrum of the guest and wherein the energy of the lowest excited triplet state of the guest is larger than the energy of the lowest excited triplet state of the host.

The invention relates to a composition comprising an organic emitter molecule, this molecule having a ΔE(S₁−T₁) value between the lowermost excited singlet state (S₁) and the triplet state beneath it (T₁) of less than 2500 cm⁻¹, and an optically inert atom or molecule for reducing the inter-system crossing time constant of the organic molecule to less than 10⁻⁶ s.

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.

Novel hydrocarbons which are excellent in heat resistance and light resistance and in solubility in organic solvents and which exhibit high energy levels of excited singlet and triplet states and wide electric oxidation-reduction potentials have partial structures represented by the general formula (I) in the molecule: (I) wherein G is a substituent represented by the general formula (II); and R<1> and R<2> are each independently an arbitrary hydrocarbon group, with the proviso that the benzene ring to which R<1>, R<2> and G are bonded has no substituent except R<1>, R<2> and G: (II) wherein R<3> to R<5> are each independently hydrogen or an arbitrary hydrocarbon group, with the proviso that the terphenyl group in the general formula (II) has no substituent except R<3> to R<5>.

A method is provided for deep tissue imaging using multi-photon excitation of a fluorescent agent. The fluorescent agent is irradiated with an ultrafast laser to produce an excited singlet state (S_n) which subsequently undergoes non-radiative relaxation to a first singlet state (S₁). The S₁ state undergoes fluorescence to the ground state S₀ to produce an emission wavelength. Both the excitation and emission wavelengths are within the near infrared optical window, thereby permitting deep tissue penetration for both the incoming and outgoing signals.

The invention provides a conjugated polymer with an aryl-containing side chain, and a preparation method and applications thereof. The conjugated polymer with an aryl-containing side chain has a structure shown as the formula (I). The energy difference between a first excited singlet state and a first excited triplet state of the polymer is small, so that the polymer has E type delay fluorescent emission, the corrugated polymer can be applied to an electroluminescence device by selecting specific polymer units and selecting a specific polymer unit ratio, the external quantum efficiency of the electroluminescence device prepared from the obtained corrugated polymer is high, and the efficiency roll-off of the electroluminescence device can be efficiently inhibited by utilizing the polymer. In addition, the preparation method of the polymer is simple, and the device can be prepared by using spin-coating, ink-jet printing and other simple solution processing modes when the polymer is used for manufacturing the device, so that the preparation method of the electroluminescence device can be greatly simplified.

The invention provides a polymer with a main chain containing a sulphone unit. The polymer is of a structure shown in a formula (I). The polymer provided by the invention has thermally induced delayed fluorescence emission as energy level difference between a first excited singlet state and a first excited triplet state of the polymer provided by the invention is smaller by selecting a specific polymerization unit and selecting a specific polymerization unit ratio; and meanwhile, when the polymer is applied to an electroluminescent device, the obtained external quantum efficiency of the electroluminescent device is high, and efficiency roll-off of the electroluminescent device can be effectively inhibited. Besides, the preparation method of the polymer provided by the invention is simple, and the obtained polymer can be prepared in simple solution processing ways such as spin coating and ink-jet printing when being used for preparing the electroluminescent device, so that a preparation technology of the electroluminescent device is greatly simplified.

The invention provides a thermal activation delayed fluorescence material and an application thereof. The thermal activation delayed fluorescence material has the following structure: a compound taking tris([1, 2, 4] triazole)[4, 3-a: 4', 3'-c: 4'', 3''-e][1, 3, 5] triazine as a receptor core has the property of thermally activated delayed fluorescence, and the receptor has a rigid planar structure, so that the thermal stability of the material is effectively improved; a large torsion angle between a donor unit and an acceptor unit can inhibit intermolecular accumulation; the solubility and the film-forming property are improved; meanwhile, the larger torsion angle can reduce overlapping of molecular front line orbits, so that the lowest excited singlet state-triplet state energy level difference is reduced, triplet state excitons can return to the singlet state through reverse intersystem crossing and finally return to the ground state in a radiation transition mode to emit fluorescence, the exciton utilization rate is increased, and finally the purpose of improving the device efficiency is achieved.

The invention relates to purely organic emitter molecules of a new type according to formula I and to the use thereof in optoelectronic devices, in particular in organic light-emitting diodes (OLEDs), comprising donor D: an aromatic or heteraromatic chemical group on which the HOMO is located and which optionally has at least one substitution; acceptor A: an aromatic or heteromatic chemical group on which the LUMO is located and which optionally has at least one substitution; bridge B1, bridge B2: organic groups that link the donor D and the acceptor A in a non-conjugated manner; wherein in particular the energy difference ΔE(S₁−T₁) between the lowest excited singlet (S1) state of the organic emitter molecule and the triplet (T1) state of the organic emitter molecule lying thereunder is less than 2000 cm⁻¹.

The invention discloses an organic electroluminescent device. The organic electroluminescent device comprises an anode, a cathode and an organic functional layer. The organic functional layer at leastcomprises a light-emitting layer, the main body material of the light-emitting layer is a thermally activated delayed fluorescent material, the energy difference [delta]Est of the excited singlet state of the main body material and the lowest excited triplet state of 77K meets a formula (1), and the energy level relation of the main body material and the guest material meets a formula (2): in theformula (1),[delta]Est(main body)<0.3eV, and in the formula (2), ES1(main body)>ES1(guest material), the guest material is selected from a type of fluorochrome with a special structure, the nuclear parent group of the compound is a triplet state energy level T1 larger than a large sterically hindered group of 2.2eV without excited state energy distribution. The device fully utilizes the triplet state energy of the main body material during electroluminescence so as to effectively improve the luminous efficiency of the device.

The invention provides a red thermal induction delay fluorescent polymer with a structure as shown in the formula (I). The provided polymer has a smaller energy level difference between a first excited singlet state and a first excited triplet state, and achieves thermal induction delay fluorescence emission; the provided polymer chooses a specific polymerization unit and the specific ratio of thepolymerization units, so that the external quantum efficiency of an obtained electroluminescent device is high when the obtained polymer is applied to the electroluminescent device, and the roll-offthe efficiency of the electroluminescent device can be inhibited. In addition, the preparation method of the provided polymer is simple, the obtained polymer can use the simple solution processing mode like spin-coating and ink-jet printing when being used to manufacture a device, so that the manufacturing process of the electroluminescent device is greatly simplified.

Disclosed is an organic electroluminescent element having a luminescent layer that comprises a host compound as a first component, a thermally-activated delayed fluorescence substance as a second component, and a boron-atom-containing compound as a third component, wherein the following relational formula is satisfied: (Excited singlet energy level determined from shoulder on peak short wavelength side of fluorescence spectrum of first component)>=(Excited singlet energy level determined from shoulder on peak short wavelength side of fluorescence spectrum of second component)>=(Excited singlet energy level determined from shoulder on peak short wavelength side of fluorescence spectrum of third component).

The invention provides an organic electroluminescent device and a display device. The organic electroluminescent device comprises a light-emitting layer; the light-emitting layer comprises a triplet state- triplet state annihilation material and a resonance type thermal activation delayed fluorescence material. The first excited singlet energy level of the triplet state-triplet state annihilation material is greater than the first excited singlet energy level of the resonance type thermal activation delayed fluorescence material, and the first excited triplet energy level of the triplet state-triplet state annihilation material is less than the first excited triplet energy level of the resonance type thermal activation delayed fluorescence material. The rotary orbit coupling constants SOC of the nth excited triplet state and the first excited singlet state of the triplet state-triplet state triplet annihilation material meet the following requirements: n is larger than or equal to 2 and is less than or equal to 6, and SOC is larger than or equal to 0.30 cm<-1>. The organic electroluminescent device provided by the invention has relatively excellent light-emitting efficiency, service life and color purity.

The invention provides a red-light thermally-induced delayed fluorescence material and a preparation method thereof, and an organic electroluminescent device. The red-light thermally-induced delayed fluorescence material provided by the invention is a red-light thermally-induced delayed fluorescence material with a multi-arm star-shaped structure as shown in a formula (I), the band gap is narrow, and the energy level difference between a first excited singlet state and a first excited triplet state is small, so that the compound has a red-light thermally-induced delayed fluorescence emission property. Moreover, a rigid truxene ketone acceptor unit contains three carbonyl groups, the reverse intersystem crossing rate of the electroluminescent material based on a truxene ketone derivative is favorably improved by utilizing the high intersystem crossing rate of the carbonyl groups, and meanwhile, the rigid plane structure is favorable for inhibiting non-radiative transition and improving the luminescent property of the material. Meanwhile, the truxene derivative as shown in the formula (I) has a multi-arm star-shaped structure, so that the weakening of intermolecular interaction is facilitated, the solubility of the material is improved, and a solution processing device is facilitated.