Abstract
Abstract Chapter I： A short synthesis of unsubstituted chrysene is described to provide a cheap source of this compound. This chrysene was used to prepare 3,6,9,12-tetrabromochrysene, which was subsequently transformed into various 3,6,9,12-tetrasubstituted chrysenes bearing four aryl, alkynyl, or amino groups by means of the Suzuki, Sonogashira, or Buchwald−Hartwig coupling reaction, respectively. These substituents result in large bathochromic shifts in the chrysene absorption and emission spectra. These new chrysene derivatives show blue fluorescent emission (401−471 nm) with high quantum yields (0.44−0.87). One representative chrysene (I-6g) was used as a blue fluorescent emitter in an OLED device that showed an outstanding external quantum efficiency (η = 6.31 %) with blue emission [CIE (x, y) = (0.13, 0.20)] and a low turn-on voltage (3.0 V). Chapter II： A series of substituted dibenzo[de, op]bistetracenes (DBBTs) is prepared in short steps and their applications to organic field-effect transistors (OFETs) are described. These DBBT derivatives bear one or two methyl-, tert-butyl-, or fluoro groups at the 2-, 10-positions. X-ray diffraction studies reveal that the molecular structures of these DBBTs were planar with a shifted π–π stacking or herringbone-stacked type packing in the crystalline state. These substituents perturb the degree of stacking shift because of steric effect and dipolar interaction, consequently affecting the electronic coupling between the neighboring molecules. Needle-like single crystals of DBBT derivatives were prepared by vapor phase transfer method and used for the fabrication of single-crystal field-effect transistors (SCFETs). Theoretical calculation on these DBBTs has been performed to correlate the measured field-effect mobility with their molecular stacking. The SCFET of di-methyl derivative II-4b showed the highest hole mobility (1.19 cm2 V-1 s-1) with a current on/off ratio of 106. Chapter III： PAH derivatives with heteroatom (boron or nitrogen) have been synthesize and prepared. These molecules were used to grow doped graphene by chemical vapor deposition, then we got single-crystal graphene and large area graphene and measure their physical properties. Boron-doped graphene was patterned and used as anode in a phosphorescent OLED device that showed an outstanding external quantum efficiency (η = 15.0 %).