Organic light-emitting devices include an anode, cathode, and a thin film containing a fluorescent organic compound and disposed between the anode and the cathode. Excitons of the fluorescent organic compound are generated by injecting electrons and holes from the electrodes, and the organic light-emitting devices utilize light emitted when the excitons are returned to the ground state. Such organic light-emitting devices are also referred to as “organic electroluminescent devices” or “organic EL devices”.
Recently, organic light-emitting devices have become markedly advanced and the possibility of a wide variety of applications has been suggested therefor because of the high luminance achieved by a low applied voltage, a variety of emission wavelengths, a high-speed responsiveness, and the possibility of realization of a thin, lightweight light-emitting devices. Heretofore, novel compounds have been actively developed. This is because creation of novel compounds is important to provide high-performance organic light-emitting devices. For example, Patent Literatures 1 to 3 describe examples of organic compounds used as the materials for a light-emitting layer.
However, from the standpoint of practical application, there is still a room for improvement in the organic compounds described in Patent Literatures 1 to 3 and organic light-emitting devices including the same. Specifically, for practical application, an optical output with higher luminance and higher conversion efficiency are necessary. Furthermore, improvements are necessary in terms of durability, for example, a change with time due to long-term use and degradation due to an atmospheric gas containing oxygen, moisture, or the like.
Furthermore, considering an application to a full-color display or the like, a blue-light emission having good color purity and high luminous efficiency is necessary. However, technologies related to these issues have not yet satisfactorily been developed. Accordingly, in particular, an organic light-emitting device having high color purity, high luminous efficiency, and high durability and a material that realizes such an organic light-emitting device have been desired.
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