Aspects of the invention provide a composition having a blend of an electron transport material and an organo alkali-metal salt wherein the salt has a glass transition greater than 115 C. The organo-alkali metal salt may be selected from the group consisting of lithium 2-(2-pyridyl)phenolate (LiPP), lithium 2-(2,2-bipyridine-6-yl)phenolate (LiBPP), 2-(isoquinoline-10-yl)phenolate (LiIQP), and lithium 2-(2-phenylquinazolin-4-yl)phenolate and lithium 2-(4-phenylquinazolin-2-yl)phenolate. In a preferred embodiment, the organo-alkali metal salt is lithium 2-(2,2-bipyridine-6-yl)phenolate (LiBPP). Aspects of the invention also provide films and devices having a film layer prepared from the composition.

Provided are a host material for a blue phosphor, and an organic thin film and an organic light-emitting device including the same. The host material for a blue phosphor is such that a carbazole compound is bonded around a central atom, wherein the central atom is a Group 14 element, and the carbazole compound bonded around the central atom is 3 or 4, wherein the carbazole compound. includes carbazole in which an alkyl group is substituted The host material for a blue phosphor has high triplet energy (ET) and excellent electrical mobility and thermal stability. As a result, the organic thin film, which includes the host material, and the organic light-emitting device, which includes the organic thin film, implement a deep blue color and have excellent luminous efficiency.

To provide a light-emitting element which uses a fluorescent material as a light-emitting substance and has higher luminous efficiency. To provide a light-emitting element which includes a mixture of a thermally activated delayed fluorescent substance and a fluorescent material. By making the emission spectrum of the thermally activated delayed fluorescent substance overlap with an absorption band on the longest wavelength side in absorption by the fluorescent material in an S.sub.1 level of the fluorescent material, energy at an S.sub.1 level of the thermally activated delayed fluorescent substance can be transferred to the S.sub.1 of the fluorescent material. Alternatively, it is also possible that the S.sub.1 of the thermally activated delayed fluorescent substance is generated from part of the energy of a T.sub.1 level of the thermally activated delayed fluorescent substance, and is transferred to the S.sub.1 of the fluorescent material.

An organic light emitting diode (OLED) having an improved service life and improved transport of negative charge carriers. The organic light emitting diode based on an organic semiconductor material in which the transport of negative charge carriers and the stability with respect to reduction are determined by azahetarylene/Lewis acid complex units. This leads to an improved service life of the emission layer, which firstly increases the service life of the component and avoids readjustment of the brightness during operation. Organic light emitting diodes are disclosed in which the position of the emission zone in the emitter layer and the color of the emission can be specifically influenced by azahetarylene/Lewis acid complex units.

To provide a light-emitting element which uses a fluorescent material as a light-emitting substance and has higher luminous efficiency. To provide a light-emitting element which includes a mixture of a thermally activated delayed fluorescent substance and a fluorescent material. By making the emission spectrum of the thermally activated delayed fluorescent substance overlap with an absorption band on the longest wavelength side in absorption by the fluorescent material in an S.sub.1 level of the fluorescent material, energy at an S.sub.1 level of the thermally activated delayed fluorescent substance can be transferred to the S.sub.1 of the fluorescent material. Alternatively, it is also possible that the Si of the thermally activated delayed fluorescent substance is generated from part of the energy of a T.sub.1 level of the thermally activated delayed fluorescent substance, and is transferred to the S.sub.1 of the fluorescent material.

A condensed cyclic compound and an organic light-emitting device including the condensed cyclic compound are provided.

A novel light-emitting device is provided. A light-emitting device with high emission efficiency is provided. A light-emitting device with a long lifetime is provided. A light-emitting device with low driving voltage is provided. The light-emitting device includes an anode, a cathode, and an EL layer between the anode and the cathode. The EL layer includes a hole-injection layer, a light-emitting layer, and an electron-transport layer. The hole-injection layer is positioned between the anode and the light-emitting layer. The electron-transport layer is positioned between the light-emitting layer and the cathode. The hole-injection layer contains a first substance and a second substance. The first substance is an organic compound which has a hole-transport property and a HOMO level higher than or equal to 5.7 eV and lower than or equal to 5.4 eV. The second substance exhibits an electron-accepting property with respect to the first substance. The electron-transport layer contains a material whose resistance decreases with current flowing therethrough.

To provide a light-emitting element which uses a fluorescent material as a light-emitting substance and has higher luminous efficiency. To provide a light-emitting element which includes a mixture of a thermally activated delayed fluorescent substance and a fluorescent material. By making the emission spectrum of the thermally activated delayed fluorescent substance overlap with an absorption band on the longest wavelength side in absorption by the fluorescent material in an S.sub.1 level of the fluorescent material, energy at an S.sub.1 level of the thermally activated delayed fluorescent substance can be transferred to the S.sub.1 of the fluorescent material. Alternatively, it is also possible that the S.sub.1 of the thermally activated delayed fluorescent substance is generated from part of the energy of a T.sub.1 level of the thermally activated delayed fluorescent substance, and is transferred to the S.sub.1 of the fluorescent material.

Provided are an organic light-emitting device satisfying a certain range of [Q(t=T50)]Polaron and an electronic apparatus including the organic light-emitting device.

Provided are a method of preparing quantum dots, a quantum dot prepared by the method, an optical member including the quantum dot, and an electronic apparatus including the quantum dot. The method includes: preparing a mixture of a semiconductor compound including indium (In), a first precursor including a first metal element, a second precursor including a second metal element, a third precursor including a third element, and a fourth precursor including a fourth element; and heating the mixture, wherein the first precursor and the second precursor are different from each other, and the third precursor and the fourth precursor are different from each other.