Synthesis And Application Of Band-gap Phosphorescent Host Materials

Ever since1987C.W Tang invented multilayer organic light emitting diode (OLED)devices, it has attracted the attention of researchers as a new technology of lighting anddisplay. Until now, the high efficiency roll off and short device lifetime of the bluephosphorescent devices are still the bottleneck. And the high triplet energy host materialsplay the most important role. Here, a series of band-gap host materials has been synthesizedand charaterized. The related points of the work were summarized as followed:1. According to the reported hole-transport and electron-transport host materials, usingthe carbazole and diphenylphosphine oxide as the subtituent group,3,6substituent fluoreneas the frame core, three host materials9,9’-(9-phenyl-9-(9-phenyl-9H-carbazol-3-yl)-9H-fluorene-3,6-diyl)bis(9H-carbazole)(BCDC),9,9’-(9,9-diphenyl-9H-fluorene-3,6-diyl)bis(9H-carbazole)(BBDC) and (9,9-diphenyl-9H-fluorene-3,6-diyl)bis(diphenylphosphineoxide)(BBDP) were synthesized and characterized. Devices have been fabricated to evaluatethe electro-luminance performances of these host materials.2. Here, we modificted the properties of the most widely used host materials mCP byintroducting electron-dificient nitrogen contained carbazole to solve the disadvantage ofmCP. New host materials5-(3-(9H-carbazol-9-yl)phenyl)-5H-pyrido[4,3-b]indole(N1MCP)，1,3-bis (5H-pyrido[4,3-b]indol-5-yl)benzene (N2MCP) and2,6-bis(5H-pyrido[4,3-b]indol-5-yl)pyridine (N3MCP) were synthesized and characterized. Devices also havebeen fabricated to evaluate the electro-luminance performances of these host materials.