Abstract: An organic electroluminescent device having an anode, a cathode, and a light-emitting layer between the anode and the cathode, wherein the light-emitting layer contains at least a first organic compound, a second organic compound and a third organic compound satisfying the following formula (A), the second organic compound is a delayed fluorescent material, and the third organic compound is a light-emitting material, has a high light emission efficiency. Formula (A): ES1(A)>ES1(B)>ES1(C) wherein ES1(A), ES1(B) and ES1(C) each represent a lowest excited singlet energy level of the first organic compound, the second organic compound and the third organic compound, respectively.

Abstract: Using a compound represented by a general formula (A)m-L-(D)n, a light-emitting device having a high emission efficiency can be provided. L is an (m+n)-valent aromatic linking group; A is a group having a positive Hammett's ?p value; D is a group having a negative Hammett's ?p value; m is an integer of 1 or more; n is an integer of 2 or more. Two of plural D's differ in point of the substituent condition at specific aromatic rings.

Abstract: An organic electroluminescent device having a structure of at least an anode 2, a light-emitting layer 3 and a cathode 4 layered in that order, wherein the light-emitting layer 3 contains a first host material, a second host material and a light-emitting material of a dopant, and both the first host material and the second host material have a lowest excited triplet energy level higher than the lowest excited triplet energy level of the light-emitting material. The device is protected from performance deterioration with time in driving and has a long lifetime.

Abstract: Disclosed is a persistent luminescence emitter containing an electron donor molecule and an electron acceptor molecule having a LUMO level of lower than ?3.5 eV, wherein emission intensity increases by temperature rise after photo-irradiation of the persistent luminescence emitter stops.

Abstract: An organic electroluminescent device having an anode, a cathode, and a light-emitting layer between the anode and the cathode, wherein the light-emitting layer contains at least a first organic compound, a second organic compound and a third organic compound satisfying the following formula (A), the second organic compound is a delayed fluorescent material, and the third organic compound is a light-emitting material, has a high light emission efficiency. Formula (A): ES1(A)>ES1(B)>ES1(C) wherein ES1(A), ES1(B) and ES1(C) each represent a lowest excited singlet energy level of the first organic compound, the second organic compound and the third organic compound, respectively.

Abstract: An organic electroluminescent device having a structure of at least an anode 2, a light-emitting layer 3 and a cathode 4 layered in that order, wherein the light-emitting layer 3 contains a first host material, a second host material and a light-emitting material of a dopant, and both the first host material and the second host material have a lowest excited triplet energy level higher than the lowest excited triplet energy level of the light-emitting material. The device is protected from performance deterioration with time in driving and has a long lifetime.

Abstract: Luminescent particles with a maximum diameter of less than 100 ?m are produced by stirring an emulsion material, including a host material, an organic luminescent material containing no heavy metal element, a surfactant and water, under conditions that melt the host material, thereby forming an emulsion, and then cooling the emulsion. This method can provide luminescent particles which are highly safe and which exhibit high luminous efficiency in water.

Abstract: Disclosed are a current excitation type organic semiconductor laser containing a pair of electrodes, an organic laser active layer and an optical resonator structure between the pair of electrodes and a laser having an organic layer on a distributed feedback grating structure. The lasers include a continuous-wave laser, a quasi-continuous-wave laser and an electrically driven semiconductor laser diode.

Abstract: An organic-inorganic perovskite satisfying ET<ET1 and ES-ET?0.1 eV has a high emission efficiency. ES represents the excited singlet energy level in emission of an inorganic component, ET represents the excited triplet energy level in emission of an inorganic component, ET1 represents the excited triplet energy level in emission of an organic component.

Abstract: When ?EST of at least one of a donor compound and an acceptor compound to form an exciplex is 0.35 eV or less, the driving lifetime of an exciplex light-emitting device can be improved.

Abstract: Disclosed is a current-injection organic semiconductor laser diode comprising a pair of electrodes, an optical resonator structure, and one or more organic layers including a light amplification layer composed of an organic semiconductor, which has a sufficient overlap between the distribution of exciton density and the electric field intensity distribution of the resonant optical mode during current injection to emit laser light.

Abstract: An organic electroluminescent device having an anode, a cathode, and a light emitting layer between the anode and the cathode, in which the light emitting layer contains a first organic compound, a second organic compound, and a third organic compound that satisfy the following expression (A), the second organic compound is a delayed fluorescent material, and the third organic compound is a light emitting material, is capable of enhancing the light emission efficiency. ES1(A), ES1(B) and ES1(C) represent a lowest, singlet excitation energy level of the first, second and third organic compound, respectively.

Abstract: An organic light-emitting device containing both a compound represented by the following general formula (1) and a compound represented by the following general formula (2) has a high light emission efficiency. The rings a to c each are a benzene ring that can be optionally condensed, R1 and R2 each represent a substituted or unsubstituted aryl group, etc., four of R31 to R35 each are a substituted or unsubstituted carbazol-9-yl group, but all of these four are not the same, and the remaining one is a hydrogen atom, a cyano group, etc.

Abstract: An organic light-emitting device having a perovskite layer having a thickness of 50 nm or more has a low drive voltage and a high power efficiency, and can suppress interelectrode short-circuiting and current leakage.

Abstract: Provided is a light-emitting device including an organic light-emitting element and a control unit that controls the organic light-emitting element. The organic light-emitting element includes a first electrode, a second electrode, and an organic light-emitting layer which is disposed between the first electrode and the second electrode and in which separation of charges occurs due to incidence of excited light. The control unit changes a potential difference between the first electrode and the second electrode so that recoupling of the charges occurs, in a second period after passage of a delay period from a first period in which the excited light is incident to the organic light-emitting layer.

Abstract: Disclosed are a current excitation type organic semiconductor laser containing a pair of electrodes, an organic laser active layer and an optical resonator structure between the pair of electrodes and a laser having an organic layer on a distributed feedback grating structure. The lasers include a continuous-wave laser, a quasi-continuous-wave laser and an electrically driven semiconductor laser diode.

Abstract: An organic light-receiving element includes an organic light-receiving layer containing a plurality of organic semiconductor molecules. Each of the plurality of organic semiconductor molecules is a molecule in which an excited state enabling reverse intersystem crossing from a lowest excited triplet state to a lowest excited singlet state is formed in each of the plurality of organic semiconductor molecules due to irradiation with light.

Abstract: Provided is an organic electroluminescent device that has a long device lifetime and is stable. The organic electroluminescent device has a light emitting layer containing first to third compounds satisfying the following formulae. ES1 is a lowest excited singlet energy and EHOMO(n) is a HOMO energy. ES1(1)>ES1(2)>ES1(3) 0 eV<EHOMO(3)-EHOMO(2)<0.

Abstract: A high-efficiency near-infrared emitting organic EL device may be provided, using a compound represented by the following general formula. At least one of R1 to R4 is *-Ar-D, or R1 and R2, R2 and R3, or R3 and R4 bond to each other to form an aromatic ring having D. D represents a donor group, and Ar represents an arylene group.

Abstract: Disclosed are a current excitation type organic semiconductor laser containing a pair of electrodes, an organic laser active layer and an optical resonator structure between the pair of electrodes and a laser having an organic layer on a distributed feedback grating structure. The lasers include a continuous-wave laser, a quasi-continuous-wave laser and an electrically driven semiconductor laser diode.