摘要:
A light-emitting element having high external quantum efficiency is provided. A light-emitting element having low drive voltage is provided. Provided is a light-emitting element which includes a light-emitting layer containing a phosphorescent compound, a first organic compound, and a second organic compound between a pair of electrodes. A combination of the first organic compound and the second organic compound forms an exciplex (excited complex). An emission spectrum of the exciplex overlaps with an absorption band located on the longest wavelength side of an absorption spectrum of the phosphorescent compound. A peak wavelength of the emission spectrum of the exciplex is longer than or equal to a peak wavelength of the absorption band located on the longest wavelength side of the absorption spectrum of the phosphorescent compound.
摘要:
An organic light-emitting element having high efficiency and long lifetime is provided. An organic light-emitting body is provided which includes a host having a high electron-transport property (n-type host), a host having a high hole-transport property (p-type host), and a guest such as an iridium complex and in which the n-type host and the p-type host are located so as to be adjacent to each other. When an electron and a hole are injected to such a light-emitting body, the electron is trapped by the n-type host and the hole is trapped by the p-type host. Then, both the electron and the hole are injected to the guest, and thus the guest is brought into an excited state. In this process, less thermal deactivation occurs and the working rate of the guest is high; thus, highly efficient light emission can be obtained.
摘要:
A light-emitting element having high external quantum efficiency is provided. A light-emitting element having a long lifetime is provided. A light-emitting element is provided which includes a light-emitting layer containing a phosphorescent compound, a first organic compound, and a second organic compound between a pair of electrodes, in which a combination of the first organic compound and the second organic compound forms an exciplex (excited complex). The light-emitting element transfers energy by utilizing an overlap between the emission spectrum of the exciplex and the absorption spectrum of the phosphorescent compound and thus has high energy transfer efficiency. Therefore, a light-emitting element having high external quantum efficiency can be obtained.
摘要:
Provided is a light-emitting element with high external quantum efficiency, or a light-emitting element with a long lifetime. The light-emitting element includes, between a pair of electrodes, a light-emitting layer including a guest material and a host material, in which an emission spectrum of the host material overlaps with an absorption spectrum of the guest material, and phosphorescence is emitted by conversion of an excitation energy of the host material into an excitation energy of the guest material. By using the overlap between the emission spectrum of the host material and the absorption spectrum of the guest material, the energy smoothly transfers from the host material to the guest material, so that the energy transfer efficiency of the light-emitting element is high. Accordingly, a light-emitting element with high external quantum efficiency can be achieved.
摘要:
A light-emitting element having extremely high efficiency of approximately 25% is provided. The light-emitting element includes a light-emitting layer which contains a phosphorescent guest, an n-type host, and a p-type host, where the light-emitting layer is interposed between an n-type layer including the n-type host and a p-type layer including the p-type host, and where the n-type host and the p-type host are able to form an exciplex in the light-emitting layer. The light-emitting element exhibits an extremely high emission efficiency (power efficiency of 74.3 lm/W, external quantum efficiency of 24.5%, energy efficiency of 19.3%) at a low driving voltage (2.6 V) at which luminance of 1200 cd/m2 is attainable.
摘要:
It is an object of the present invention to obtain an organometallic complex that is capable of converting an excited triplet state into luminescence, a light-emitting element that can be driven for a long time, is high in luminous efficiency, and has a favorable long lifetime, and a light-emitting device using the light-emitting element. The present invention provides a light-emitting element that has a pair of electrodes (an anode and a cathode) and a light-emitting layer between a pair of electrodes, where the light-emitting layer includes an organometallic complex represented by the following general formula (5) and one of a compound that has a larger energy gap than the organometallic complex and a compound that has a larger ionization potential and a smaller electron affinity than the organometallic complex, and provides a light-emitting device using the light-emitting device.
摘要:
To provide a light-emitting element with high emission efficiency or long lifetime, in which the use amount of a phosphorescent compound is small. To provide a light-emitting element including a light-emitting layer between a pair of electrodes, wherein the light-emitting layer includes a phosphorescent compound, a first organic compound, and a second organic compound, and the combination of the first organic compound and the second organic compound forms an exciplex. The light-emitting element transfers energy by utilizing the overlap between the emission spectrum of the exciplex and the absorption spectrum of the phosphorescent compound and thus has high energy transfer efficiency, even when the concentration of the phosphorescent compound is low.
摘要:
A light-emitting element having high emission efficiency and long lifetime is provided. By manufacturing a light-emitting device using the light-emitting element, the light-emitting device having low power consumption and long lifetime is provided. The light-emitting element is manufactured in which a light-emitting layer is included between a first electrode serving as an anode and a second electrode serving as a cathode. The light-emitting layer includes a first organic compound having a hole-transporting property, a second organic compound having an electron-transporting property, and an organometallic complex including a dibenzo[f,h]quinoxaline skeleton as a ligand. Further, a light-emitting device is manufactured using the light-emitting element.
摘要:
A light-emitting element is provided which has a light-emitting layer between a first electrode and a second electrode, where the light-emitting layer has a first layer and a second layer; the first layer contains a first organic compound and a third organic compound; the second layer contains a second organic compound and the third organic compound; the first layer is provided to be in contact with the second layer on the first electrode side; the first organic compound is an organic compound with an electron transporting property; the second organic compound is an organic compound with a hole transporting property; the third organic compound has an electron trapping property; and light emission from the third organic compound can be obtained when voltage is applied to the first electrode and the second electrode so that the potential of the first electrode is higher than that of the second electrode.
摘要:
A light-emitting element is provided which has a light-emitting layer between a first electrode and a second electrode, where the light-emitting layer has a first layer and a second layer; the first layer contains a first organic compound and a third organic compound; the second layer contains a second organic compound and the third organic compound; the first layer is provided to be in contact with the second layer on the first electrode side; the first organic compound is an organic compound with an electron transporting property; the second organic compound is an organic compound with a hole transporting property; the third organic compound has an electron trapping property; and light emission from the third organic compound can be obtained when voltage is applied to the first electrode and the second electrode so that the potential of the first electrode is higher than that of the second electrode.