高熱穩定性有機電激發光材料之合成

Abstract

本論文分為三部份，分別針對高熱穩定性的有機電激發光二極體之電洞傳輸材料、藍光發光材料、與高分子電激發光二極體的電子傳輸材料之合成與性質及元件做討論。 在A部份中，我們設計了新的電洞傳輸材料Adm-TPD和Adm-NPB，在Pd complexes的催化下合成出具有高度立體障礙的spiro-fluorene-金鋼烷(adamantane)之小分子，由於以剛硬的spiro-fluorene為中心結構，這些triaryldiamines分子表現出高度的熱穩定性及薄膜型態的穩定度。 在B部份中，我們將pyrazoloquinolines的化合物中導入9,9¢-螺結雙茀結構，剛硬的spiro中心讓這個小分子化合物成為具有高熱穩定性的藍光發光材料，並設計製程有機發光二極體藍光元件結構，使其在元件中扮演客發光體的角色，且探討其元件性質。 在C部份中，以Friedländer condensation 合成出主鏈含有cardo及9,9¢-螺結雙茀結構的聚奎琳高分子，由於雙茀的共軛架構被一個四級碳以σ鍵方式連結且相互垂直，可增加高分子的溶解度以及加強分子鏈的剛硬度，進而提高高分子的熱穩定性。由電化學研究，此系列聚奎琳具有較低的LUMO能階，顯示此類的聚奎琳可以擔任高分子發光二極體元件的電子傳輸/電洞阻隔材料。

This thesis is divided into three parts regarding the synthesis and characterization of hole transport, electron transport, and blue-emitting materials, which exhibit pronounced thermal stabilities. We also report the fabrication and performances of OLEDs based on these materials. In part A, new hole-transport materials, Adm-TPD and Adm-NPB, which contain a spiro(adamantane-2,9¢-fluorene) core, are synthesized and characterized. Attributed to the rigid spiro-fluorene core, these triaryldiamines exhibit higher glass transition temperatures (Tg) and have a less tendency toward crystallization, in comparison with their biphenyl analogs. In part B, we report on the synthesis of pyrazoloquinolines containing 9,9¢-spirobifluorene. The spiro-annulated segment would be expected to enhance the rigidity, leading to a significant increase in both Tg values and thermal stability. Moreover, these pyrazoloquinolines are used as dopants in organic light-emitting diodes, they give a bright blue color. In part C, polyquinolines, which contain cardo and 9,9¢-spirobifluorene unit in the main chain, are synthesized via the acid-catalyzed Friedländer condensation reactions of bis(o-aminoketone) with bisacetyl monomers. In the spiro-fused bifluorene moiety, the two mutually perpendicular fluorene rings are connected via a common tetracoordinated carbon atom. This structural feature leads to polymers that possess high thermal stability and good solubility in common organic solvents. The electrochemical behaviors of these polymers were investigated by cyclic voltammetry. The reversible reduction and low-lying LUMO energy level suggest that some of the polyquinolines might have favorable potential for use as materials for electron injection and transport in polymer light-emitting diodes.