Abstract: Using three 9,10-bis-styrylanthracene derivatives (BSA's) with different substituents for emission layer materials, various types of electroluminescent (EL) devices were fabricated. Combining with a triphenylamine derivative as a hole transport layer material and an oxadiazole derivative as an electron transport layer material, two-layer type and three-layer type devices were fabricated. We found that the performances of two- and three-layer type devices were largely dependent on the electronic nature of emission layer materials. We found that the BSA's attached with electron-donating groups have the specific electronic nature which allowed the transport of both electrons and holes. A single layer device with about 100 nm-thick BSA layer showed high luminance comparable with conventional two-layer type devices. Two-layer type devices which consisted of two different BSA layers were prepared in order to confirm that BSA layers surely behave as both electron and hole transporting materials. BSA with an electron-accepting substituent surely behaved as an electron transport material. In contrast, BSA's with electron-donating groups showed the bipolar charge transporting characteristics, which means the capability of transport of both electrons and holes.!12
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