Iron-based photosensitizers, which can be used for solar energy conversion and photoluminescence applications, include an iron complex with N-heterocyclic carbene (NHC) ligands (FeNHC), a linking unit, and a polarizable unit formed of a pi conjugated structure having a one-electron reduction potential more positive than NHC.

Provided is an ionic type phosphorescent metal complex with a racemization structure, a preparation method therefor and a use thereof. The structure of the complex is [PtAg.sub.2{rac-(PPh.sub.2CH.sub.2PPhCH.sub.2—).sub.2}(C≡CR).sub.2(PR′.sub.3).sub.2].sup.2+A.sup.n−.sub.2/n or [PtAg.sub.2{meso-(PPh.sub.2CH.sub.2PPhCH.sub.2—).sub.2}(C≡CR).sub.2(PR′.sub.3)(μ-X)].sup.+.sub.mA.sup.m−, wherein R is the same or different and is independently selected from alkyl, aryl, heteroaryl, and heteroaryl aryl; R′ is the same or different and is independently selected from alkyl, aryl, and heteroaryl; the alkyl, aryl, and heteroaryl can be substituted by one or more substituents which are selected from alkyl, alkenyl, alkynyl, alkoxy, amino, halogen, halogenated alkyl, and aryl; X is halogen; A.sup.m− and A.sup.n− are monovalent or bivalent anions; and m or n is 1 or 2. The present invention also relates to an organic light emitting diode, a preparation method therefor and use thereof. The organic light emitting diode prepared by taking the phosphorescent metal complex of the present invention as a luminous layer dopant has high-performance organic electroluminescence and can be applied to panel display.

The present invention relates to an organic electroluminescent device comprising a first electrode, at least one second electrode, at least one emission layer and at least one electron transport region, wherein the emission layer and the electron transport region are arranged between the at least one second electrode and the first and the electron transport region is arranged between the emission layer and the at least one second electrode, wherein the at least one electron transport region comprises a first electron transport layer, the first electron transport layer preferably not comprising an n-type dopant; and a performance enhancement layer, the performance enhancement layer having a refractive index of ≤1.6 at a wavelength of 1,200 nm; wherein the first electron transport layer is arranged between the emission layer and the performance enhancement layer; and the performance enhancement layer is arranged between the first electron transport layer and the at least one second electrode.

The present invention discloses a patterned perovskite film, a preparation method thereof, and a display device. The method includes mixing a perovskite precursor and a photo-initiated polymer monomer, and realizing polymerization of a part of a predetermined area under shielding of a photomask, that is, the formed perovskite crystals are encapsulated by the formed polymer with formation of the patterned perovskite film.

To provide a light-emitting element with high emission efficiency and low driving voltage. The light-emitting element includes a guest material and a host material. A LUMO level of the host material is higher than a LUMO level of the host material, and a HOMO level of the guest material is lower than a HOMO level of the host material. The guest material has a function of converting triplet excitation energy into light emission. The difference between a singlet excitation energy level and a triplet excitation energy level of the host material is greater than 0 eV and less than or equal to 0.2 eV. The energy difference between the LUMO level and the HOMO level of the host material is larger than or equal to light emission energy of the guest material.

Disclosed is a polycyclic aromatic compound that can be employed in an organic layer of an organic electroluminescent device. Also disclosed is an organic electroluminescent device including the polycyclic aromatic compound. The use of the polycyclic aromatic compound significantly improves the luminous efficiency of the device and ensures high efficiency and long lifetime of the device.

Multilayer structures comprising a covalent organic framework (COF) film in contact with a polyaromatic carbon (PAC) film. The multilayer structures can be made by combining precursor compounds in the presence of a PAC film. The PAC film can be for example, a single layer graphene film. The multilayer structures can be used in a variety of applications such as solar cells, flexible displays, lighting devices, RFID tags, sensors, photoreceptors, batteries, capacitors, gas-storage devices, and gas-separation devices.

The present invention relates to heteroleptic complexes comprising a phenylimidazole or phenyltriazole unit bonded via a carbene bond to a central metal atom, and phenylimidazole ligands attached via a nitrogen-metal bond to the central atom, to OLEDs which comprise such heteroleptic complexes, to light-emitting layers comprising at least one such heteroleptic complex, to a device selected from the group consisting of illuminating elements, stationary visual display units and mobile visual display units comprising such an OLED, to the use of such a heteroleptic complex in OLEDs, for example as emitter, matrix material, charge transport material and/or charge blocker.

To provide a light-emitting device not only including a light-emitting layer in which energy is efficiently transferred from a host material to a guest material but also having high reliability. The light-emitting device not only includes a light-emitting layer in which the T1 levels and the S1 levels of a host material and a guest material fall within certain ranges so that energy can be efficiently transferred from the host material to the guest material and but also has improved reliability.

A light-emitting polymer comprising a light-emitting repeat unit in a backbone of the polymer, wherein the polymer has an anisotropy of no more than 0.8 and wherein a transition dipole moment of the light-emitting repeat unit is aligned with the polymer backbone.