A light-emitting element containing a light-emitting material with high light emission efficiency is provided. The light-emitting element includes a high molecular material and a guest material. The high molecular material includes at least a first high molecular chain and a second high molecular chain. The guest material has a function of exhibiting fluorescence or converting triplet excitation energy into light emission. The first high molecular chain and the second high molecular chain each include a first skeleton, a second skeleton, and a third skeleton, and the first skeleton and the second skeleton are bonded to each other through the third skeleton. The first high molecular chain and the second high molecular chain have a function of forming an excited complex.

A light-emitting element containing a light-emitting material with high light emission efficiency is provided. The light-emitting element includes a high molecular material and a guest material. The high molecular material includes at least a first high molecular chain and a second high molecular chain. The guest material has a function of exhibiting fluorescence or converting triplet excitation energy into light emission. The first high molecular chain and the second high molecular chain each include a first skeleton, a second skeleton, and a third skeleton, and the first skeleton and the second skeleton are bonded to each other through the third skeleton. The first high molecular chain and the second high molecular chain have a function of forming an excited complex.

A multicolor light-emitting element using fluorescence and phosphorescence, which has a small number of manufacturing steps owing to a relatively small number of layers to be formed and is advantageous for practical application can be provided. In addition, a multicolor light-emitting element using fluorescence and phosphorescence, which has favorable emission efficiency is provided. A light-emitting element which includes a light-emitting layer having a stacked-layer structure of a first light-emitting layer exhibiting light emission from a first exciplex and a second light-emitting layer exhibiting phosphorescence is provided.

A light-emitting element containing a light-emitting material with high light emission efficiency is provided. The light-emitting element includes a high molecular material and a guest material. The high molecular material includes at least a first high molecular chain and a second high molecular chain. The guest material has a function of exhibiting fluorescence or converting triplet excitation energy into light emission. The first high molecular chain and the second high molecular chain each include a first skeleton, a second skeleton, and a third skeleton, and the first skeleton and the second skeleton are bonded to each other through the third skeleton. The first high molecular chain and the second high molecular chain have a function of forming an excited complex.

A light-emitting element is provided. The light-emitting element includes first and second electrodes and an EL layer therebetween. The EL layer includes a light-emitting layer containing first and second substances. The amount of the first substance is larger than that of the second substance. The second substance emits light. Average transition dipole moments of the second substance are divided into three components in x-, y-, and z-directions which are orthogonal to each other. Components parallel to the first or second electrode are assumed to be the components in the x- and y-directions, and a component perpendicular to the first or second electrode is assumed to be the component in the z-direction. The proportion of the component in the z-direction is represented by a, which is less than or equal to 0.2.

An organic light-emitting device and an electronic apparatus including the same are provided. The organic light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer provided between the first electrode and the second electrode and including an emission layer, wherein the emission layer includes a first compound that is a hole-transporting compound, a second compound that is an electron-transporting compound, a third compound capable of emitting phosphorescence, and a fourth compound capable of emitting delayed fluorescence, and a value of R.sup.0 is at least 3.5 nm.

A light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer between the first electrode and the second electrode and including an emission layer, wherein the emission layer includes a first compound, a second compound, a transition metal-containing compound, and a delayed fluorescence compound, the first compound being a hole transport material, and the second compound being an electron transport material, the first compound and the second compound form an exciplex, the first compound, the second compound, or any combination thereof is substituted with at least one deuterium, and an absolute value of a triplet charge transfer state-singlet ground state non-radiative decay rate constant of a mixture of the first compound and the second compound is decreased, compared to a case in which the first compound, the second compound, or any combination thereof is not substituted with deuterium.

An organic electroluminescent device, a display panel, and a display device are disclosed. The organic electroluminescent device includes: an anode and a cathode disposed opposite to each other, a light emitting layer located between the anode and the cathode, an electron blocking layer located between the light emitting layer and the anode, and a hole transport layer located between the electron blocking layer and the anode. The light emitting layer includes an exciplex formed by mixing an electron-type host material and a hole-type host material, and a guest material with which the exciplex is doped. The electron mobility of the hole transport layer is greater than that of the electron blocking layer.

An organic light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an organic layer located between the first electrode and the second electrode and including an emission layer, wherein the emission layer includes a host and a dopant, the host includes a first compound and a second compound, and the first compound, the second compound, and the dopant are different from one another. Two compounds in the host included in the emission layer may have different HOMO and LUMO energy levels and may form an exciplex, and a difference between a HOMO energy level and a LUMO energy level of the exciplex (?E.sub.exciplex) may be greater than a difference between a HOMO energy level and a LUMO energy level of the dopant (?E.sub.dopant).

A light-emitting element is provided. The light-emitting element includes first and second electrodes and an EL layer therebetween. The EL layer includes a light-emitting layer containing first and second substances. The amount of the first substance is larger than that of the second substance. The second substance emits light. Average transition dipole moments of the second substance are divided into three components in x-, y-, and z-directions which are orthogonal to each other. Components parallel to the first or second electrode are assumed to be the components in the x- and y-directions, and a component perpendicular to the first or second electrode is assumed to be the component in the z-direction. The proportion of the component in the z-direction is represented by a, which is less than or equal to 0.2.