以吡啶修飾咔唑與三唑雙偶極化合物之合成、性質探討及其在藍色磷光有機發光二極體的應用

Abstract

本篇論文合成出一系列作為藍光主發光體的衍生物，是以三唑基團作為受體 (acceptor)，咔唑的基團作為施體 (donor)，並以吡啶修飾咔唑所構成的雙偶極 (bipolar) 化合物。 利用吡啶增加咔唑的氧化難度，降低HOMO能階，提供高三重態能階。以X-Ray單晶繞射觀察晶體結構與排列情形；以紫外-可見光吸收光譜、螢光放射光譜與磷光放射光譜測量光化學性質；以循環伏安法與差式脈波伏安法測量電化學性質並進行討論。結果發現，三唑基團接在咔唑基團不同位置上會導致排列方式不同，造成衍生物間有不同的熔點。電化學性質方面，將咔唑基團上的氮原子接上吡啶，確實可將氧化電位延後，增加咔唑的氧化難度。 將合成出的一系列作為藍光主發光體的衍生物材料，並製作成多層式有機電激磷光二極體元件，並測量效率。化合物7為主發光體所製成的元件在最大亮度值 (10620 cd/A)、最佳發光效率 (52.64 cd/A)、最大外部量子效率 (24.00 %) 及在效率隨電流密度提高而降低 (roll-off) 有最佳的表現；化合物10則是在最佳發光功率 (42.12 lm/W) 方面表現最佳。

A series of bipolar derivatives as host materials containing triazole group as acceptor, and carbazole-pyridine group as (donor) for blue phosphorescent organic light emitting diodes (PhOLED) has been synthesized. Increasing the oxidation difficulty of carbazole by using pyridine to reduce energy level of HOMO, the way provides high triplet energy level. X-ray crystallography, UV-Vis spectrum, photoluminescence, cyclic voltammetry and differential pulse voltammetry have been used to analyze the propertied of the series of bipolar derivatives. It was found that differences in the connected position of triazole group on carbazole will lead to a different arrangement, resulting in between derivatives have different melting points. Utilizing pyridine connected the nitrogen of carbazole lead to oxidation potential be delayed, resulting in the difficulty of carbazole oxidation. The series of bipolar derivatives as host materials made into a multi-layered organic phosphors excited diode device and measure efficiency. The device of compound 7 as host material has better performing than other compounds in the maximum luminance value (10620 cd/A), the maximum current efficiency (52.64 cd/A), the maximum external quantum efficiency (24.00 %), and roll-off. The device of compound 10 as host material has better performing than other compounds in the maximum power efficiency (42.75 lm/W).