以咔唑及芴為核心之給體-受體分子的合成、性質與應用

Abstract

本論文主要分兩部分，第一部分: 利用具有高電洞傳輸性質的咔唑為核心，利用合成方式於其3、6位置上，取代具有電子傳輸性質的基團，包括: 苯並咪唑 (benzimidazole)、吡啶 (pyridine)、噁二唑 (oxadiazole) 以及芳香硼的一系列衍生物。藉由結合電洞與電子傳輸性質的基團，發展出具有雙極性 (Bipolar) 或雙偶極性 (Ambipolar) 的主體材料，依其物理性質來搭配客體磷光材料使用。其中CMesB可作為主體材層搭配藍色磷光材料Firpic (ηext = 12 %, ηp = 19 lm/W) 與綠光磷光材料Ir(ppy)2acac (ηext = 16 %, ηp = 34 lm/W)；COxaPh之三重激發態能階較低只適合搭配綠光磷光材料Ir(ppy)2acac (ηext = 18 %, ηp = 76 lm/W) 與紅光磷光材料OS2 (ηext = 21 %, ηp = 36 lm/W)；CBzIm目前則與藍光磷光材料NFirpic (16 %, ηp = 29 lm/W) 摻混效果最佳；而CPhBzIm則是一個相當特別的材料，除了可以直接作為深藍光螢光發光層使用 (ηext = 3 %, CIE = 0.16, 0.05)，搭配黃綠光磷光材料Ir(pbi)2acac 效率也相當高 (ηext = 19.2 %, ηp = 62 lm/W, CIE = 0.42;0.56)，更能製作單一摻混之白光元件 (ηext = 7 %, CIE = 0.31, 0.33)；另外的結構異構物CNBzIm則分別搭配藍光Firpic (13 %, ηp = 31 lm/W)、綠光Ir(ppy)2acac (18 %, ηp = 59 lm/W)、紅光OS2 (ηext = 19 %, ηp = 27 lm/W) 以及共摻混成的白光元件都有不錯的效率 (ηext = 16 %, ηp = 37 lm/W)；CAymPy與CSymPy因分子性質相近，作為主體材料製成的元件，分別搭配綠光磷光材料Ir(ppy)2acac (CAymPy, ηext = 12 %, ηp = 47 lm/W；CSymPy, ηext = 11 %, ηp = 42 lm/W) 與紅光磷光材料Ir(mpq)2acac (CAymPy, ηext = 11 %, ηp = 12 lm/W；CSymPy, ηext = 8 %, ηp = 9 lm/W) 可得到相似的元件效率。總結來說，我們設計與合成之雙極性主體材料應用於有機發光二極體確實具有相當好的結果。 第二部分: 以芴基為核心之π-共軛系統上，利用鈀金屬催化方式於其3、6位置上，引入具有給體 (Donor) 效果的芳香胺，再利用縮合反應於芴之9號位置帶入多種具有受體 (Acceptor) 性質的拉電子基團。此新型的給體-受體分子，具有發展有機薄膜太陽能與雙光子吸收之光動力療法等應用性。其中LCC-1作為p-type 材料與C60共蒸鍍而成的單層異質接面太陽能電池，於標準太陽光下效率約1 %，IPCE最大值為35 % (498 nm)。另外雙光子吸收之光動力療法上的應用，則在初步測試以化合物17有最高的雙光子吸收係數 (1636 GM)，以及和參考品H2TPP比較後最佳之單重態氧的生成效率 (＞100 %)。

This thesis is composed of two major parts. For the first part, we have successfully synthesized a series of bipolar hosts by introducing two electron-withdrawing moieties onto the 3 and 6 positions of N-phenyl carbazole. The introduced electron-withdrawing blocks are dimesityl boron, phenylbenzimidazole, pyridine, and oxadiazole. The new molecules obtained by different structure combinations have led to different film-forming property, comparable electron and hole mobilities, tunable triplet energies and energy levels which govern their various applications as host materials in phosphorescent organic light-emitting devices (PhOLEDs) with good to excellent external quantum efficiencies (EQE). Among those, CMesB can serve as host material for doping with Firpic (ηext = 12 %, ηp = 19 lm/W) and Ir(ppy)2acac (ηext = 16 %, ηp = 34 lm/W) to realize efficient blue and green PhOLEDs, respectively. High performance PhOLEDs have been achieved with COxaPh as host material doping with green emmitters Ir(ppy)2acac (ηext = 18 %, ηp = 76 lm/W) and red emmiter OS2 (ηext = 21 %, ηp = 36 lm/W). CBzIm can dope with NFirpic) to get a blue PhOLED with EQE up to 16 % and ηp = 29 lm/W. Due to its high photoluminescence, CPhBzIm was not only used to fabricate non-doped deep blue-emitting devices with promising performance (ηext = 3 %, CIE = 0.16; 0.05), but also served as host material doped with Ir(pbi)2acac to realize green PhOLED (ηext = 19.2 %, CIE = 0.42; 0.56). Furthermore, we have demonstrated a simple single-doped way to realize two-color based WOLEDs (ηext = 7 %, CIE = 0.31, 0.33) by using the dual roles of CPhBzIm. CNBzIm served as a universal host host material for Firpic (13 %, ηp = 31 lm/W), Ir(ppy)2acac (18 %, ηp = 59 lm/W), OS2 (ηext = 19 %, ηp = 27 lm/W), and WOLEDs (ηext = 16 %, ηp = 37 lm/W). CAymPy and CSymPy have similar physical properties which were applied as host materials gave devices with Ir(ppy)2acac as emitter (CAymPy, ηext = 12 %, ηp = 47 lm/W, CSymPy, ηext = 11 %, ηp = 42 lm/W) and Ir(mpq)2acac as emitter (CAymPy, ηext = 11 %, ηp = 12 lm/W；CSymPy, ηext = 8 %, ηp = 9 lm/W). The second part, we have successfully synthesized a series of novel bipolar molecules with various donors and acceptors which were bridged with a fluorene conjugation. The donors, mainly diaryl amino groups, were introduced onto the C3 and C6 of the fluorenone core employing Hartwig’s palladium-catalyzed C-N bond coupling reaction of 3,6-dibromofluorenone and diarylamines. After then, cyanoacetic acid, dicyano , and diethyl malonate were introduced as the acceptor parts onto the 9-position of the fluorenone by Knoevenagel condensation. Those bipolar materials have shown to have potential applications of organic thin-film solar cell and photodynamic therapy. The photovoltaic bulk heterojunction solar cells with p-type LCC-1 as the dye in combining with C60 as the electron acceptor have been fabricated by thermal evaporation. These devices have reached power conversion efficiencies of ~1 % and IPCE at 498 nm up to 35 % under simulated AM 1.5 solar irradiation at 100 mWcm-2. In addition, compounds 17 was found to exhibit larger two-photon absorption (TPA) cross section value of 1636 GM as measured by the two photon induced fluorescence. More strikingly, the best single-photon singlet oxygen generation quantum yield (＞100 %) as compared to that of the standard tetraphenylporphyrin (H2TPP) was observed, which indicates the highly potential application in photodynamic therapy is possible in the dye can be designed to interact with cells.