Organic compound, light-emitting element, light-emitting device, electronic device, and lighting device
摘要
說(shuō)明書(shū)
A benzofuro[3,2-d]pyrimidine skeleton and a benzothieno[3,2-d]pyrimidine skeleton are preferably used as the benzofuropyrimidine skeleton and the benzothienopyrimidine skeleton, respectively, because of being available at low cost.
A structure in which a benzofuro[3,2-d]pyrimidine skeleton or a benzothieno[3,2-d]pyrimidine skeleton includes a substituent including one condensed ring or two condensed rings is preferable because the structure is effective in improving electrochemical stability and film quality, so that the reliability of a light-emitting element can be improved.
A structure in which a bicarbazole skeleton is bonded to the 4-position of the benzofuro[3,2-d]pyrimidine skeleton or the benzothieno[3,2-d]pyrimidine skeleton directly or through an arylene group is preferable because the structure has high electrochemical stability and a high carrier-transport property and a highly reliable light-emitting element with low driving voltage can be provided.
In the case where the bicarbazole skeleton is directly bonded to the benzofuropyrimidine skeleton or the benzothienopyrimidine skeleton, a relatively low molecular compound is formed, and therefore, a structure that is suitable for vacuum evaporation is obtained, which is preferable for a material for a light-emitting element. In general, a lower molecular weight tends to reduce heat resistance after film formation. However, because of high rigidity of the benzofuropyrimidine skeleton, the benzothienopyrimidine skeleton, and the bicarbazole skeleton, the compound of one embodiment of the present invention can have sufficient heat resistance even with a relatively low molecular weight. The structure is preferable because a band gap and an excitation energy level are increased.
