Kassel, Univ., Diss., 2008 / Erscheinungsjahr an der Haupttitelstelle: 2007

Universiẗat, Diss., 2002--Kassel.

Recently, ¡§Pyrene¡¨ is a well-known substitutive group because the rigid structure and hole-injection ability of pyrene units can improve the thermal and electronic properties of blue OLED materials. The aromatic ring of pyrene not only improves the thermal and hole-injection ability of derivatives, but also provides high photoluminescence (PL) efficiency and high carrier mobility. Through these characteristics we can understand that the electron-rich pyrene derivatives can enhance the properties of OLED device. In this study, we developed low-molecular-weight structures with spiro-type molecules based on 9,9-spirobifluorene and fabricated the OLED device with the structure of ITO(170 nm)/PEDOT:PSS(50 nm)/PVK:TPSBF (40%)(90 mm)/BPhen (30 nm)/ LiF(1 nm)/Al(200 nm). It exhibited a maximum luminance at 500 mA/cm2 of 4130 cd/m2 with the Commission Internationale de l'Eclairage (CIE) of (0.16 , 0.16), and the maximum current and power efficiency were 1.9 cd/A and 0.9 lm/W, respectively. We concluded that TPSBF has good emission efficiency according to device performances. The PL maximum of the thick film of TPSBF, prepared by vacuum vapor deposition appears broadband spectrum, that resulted from the aggregation of the pyrene moieties. From Atomatic Force Microscopy (AFM) results, we propose three emission mechanisms. 1. Intramolecular spectrum ¡÷ 450 nm 2. Molecular aggregation spectrum ¡÷ 500 nm 3. Longer conjugation spectrum of intermolecular ¡÷ 550 nm We could fabricate the organic white light emitting device with a single and thicker emitting layer TPSBF and the more broadband emitting spectrum can be obtained. Finally, we fabricated the organic white light emitting device with a structure of ITO(170 nm)/2T-NATA(15 nm)/NPB(65 nm)/TPSBF(50 nm)/Alq3(30 nm)/LiF(0.8 nm)/Al(200 nm). It exhibited a maximum luminance at 1300 mA/cm2 of 57680 cd/m2, the maximum current and power efficiency were 6.51 cd/A and 4.07 lm/W, respectively, and with good CIE coordinate of (0.29 , 0.36).

Kassel, Universiẗat, Diss., 2007.

Les oligophénylènes constituent une classe de molécules centrale dans la conception de semi-conducteurs organiques pour des applications optoélectroniques. Ces travaux portent sur la synthèse et l’étude approfondie de dérivés linéaires et cycliques du fluorène (un biphényle rigidifié par un pont méthylène), fragment constitutif essentiel dans l’électronique organique. Nous nous intéressons en particulier aux relations structure-propriétés de ces systèmes π-conjugués. Dans une première partie, avec comme cadre le développement de matériaux hôtes pour diodes électroluminescentes (PhOLEDs), nous présentons une étude de la régioisomérie de phényl-fluorènes et de phényl-spirobifluorènes. Ses résultats ont permis la préparation de quatre matériaux hôtes purs hydrocarbures, dimères de spirobifluorène, intégrés dans des PhOLEDs bleues à hautes performances. Dans une seconde partie, nous nous intéressons au domaine récent des nano-anneaux moléculaires, objets cycliques présentant une conjugaison π de nature singulière. Après une revue bibliographique portant sur les cycloparaphénylènes et leurs propriétés, nous présentons nos études concernant plusieurs exemples de leurs analogues pontés : les cycloparafluorènes. / Oligophenylenes constitute a major class of molecules in the design of organic semiconductors for optoelectronics applications. This work involves the synthesis and in-depth study of linear and cyclic derivatives of fluorene (a biphenyl rigidified by a methylene bridge), an essential building block in organic electronics. We focus our attention on the structure-property relationships of these π-conjugated systems. In a first part, within the framework of host materials for phosphorescent organic light-emitting diodes (PhOLEDs), we present a regioisomerism study of phenyl-fluorenes and phenyl-spirobifluorenes. Its results enabled the preparation of four pure hydrocarbon host materials, spirobifluorene dimers, used in high-performance blue PhOLEDs. In a second part, we take interest in the emerging field of molecular nanorings, cyclic objects presenting a singular nature of π-conjugation. After a bibliographical review covering cycloparaphenylenes and their properties, we present our studies regarding several examples of their bridged analogues: cycloparafluorenes.