2,2’雙取代與2,2’,7,7’四取代旋環雙芴材料之合成及其光電應用

Abstract

以旋環雙芴為核心結構，分別在2,2’與2,2’,7,7’位置引入不同基團，設計合成出ㄧ系列具雙共軛的材料，兩相正交相互獨立的共軛鏈，使分子具光學異構物，可避免分子堆疊，提高熱穩定性。 高能隙材料具短共軛、高電化學穩定性與高熱穩定性的特點，將SS與TS作為UV-發光材料時，元件外部量子產率高於2.6%，最高亮度4020 cd/m2；亦可作為磷光材料之主體材料。芳香胺外圍取代之電洞材料DPAS可與TCTA搭配做為雙電洞傳導層，應用於藍光磷光元件中，具有極高之效能表現。在核心結構分別引入不同之推、拉電子基團，可調控出紅藍綠之放光波長；此外，發現到CNSDA具有穩定且色彩明顯之電致變色行為，具極高之應用潛力。另外，我們設計出單色團與雙色團分子，觀察其在不同氧化態之吸收光譜變化，推測以旋環架構橋接雙共軛系統之氧化行為，應是單步驟單電子之機制。

we have designed and synthesized 9,9’-spirobifluorene-based materials and introduced different functional group at 2,2’ and 2,2’,7,7’ positions of 9,9’-spirobifluorene. All of these obtained materials adopted a bichromophoric system configured orthogonally via a chiral spiro center. The perpendicular arrangement can efficiently suppress cryastallization and improve thermal stability of the resulting materials. Large energy gap spiro-configured bifluorenes can be used as efficient emitters in UV OLEDs and as effective host materials for red electrophosphorescent devices. In addition, diarylamine substituted material DPAS was used together with TCTA as a co-hole transporting layer in highly efficient blue electrophosphorescent device. Materials emitting RGB colors can be readily accessed by introducing different donor and acceptor moieties. Among them, we have found some interesting spectroelectrochemical behavior of CNSDA, which shows high potential in applications of electrochromic device. In addition, we have designed mono- and bi-chromophore systems for investigating the electronic interactions within spiro-bridged systems. According to the observed, consecutive changes on absorption spectra from neutral sate to second oxidation state. We proposed the oxidation behavior of spiro-configured bichromophore systems is through a one-step-one-electron mechanism.