高效率固態有機黃光電化學元件

Highly Efficient Solid-State Yellow Light-Emitting Electrochemical Cells

羅价良(Chieh-Liang Lo)

指導教授 ： 蘇海清

國立交通大學/光電學院/光電科技學程/碩士(2019年)

摘要

近年來有機發光二極體 (organic light-emitting diodes, OLEDs)因其高對比度，廣視角及低功耗等特性，在照明與顯示領域被廣泛討論，其中使用離子性過渡金屬錯合物 (ionic transition-metal complexes, iTMCs)製作的有機發光電化學元件(light-emitting electrochemical cells, LECs)，因構造簡單具有比一般小分子OLED更低的操作電壓，此外溶劑製程也使得LEC具有做為大面積顯示器的潛力。
本論文將分成三個部分討論離子性銥金屬錯合物[Ir(bppz)2(BPhen)]+(PF6-)，其中bppz為Butylphenylpyrazole，BPhen為4,7-Diphenyl-1,10-phenanthroline，在電致發光元件上之應用。在第一部分，我們將針對錯合物進行厚度優化，得到最高外部量子效率為13%，功率效率為34.3 lm/W。
第二部分，以藍光離子性銥金屬錯合物[Ir(dfppz)2(dmbpy)]+(PF6-)，其中dfppz為1-(2′,4′-difluorophenyl)pyrazole，dmbpy為4,4'-dimethyl-2,2'-bipyridine，作為主體並透過主客體摻雜機制製成六組不同摻雜比例的有機發光電化學元件，由於自我猝熄受到抑制，最高外部量子效率可提高到16.6%，功率效率為56.2 lm/W。
第三部分，我們延續主客體摻雜實驗所得知的最佳摻雜比例，並透過使用含有內嵌式散射層的複合式基板，使元件整體出光上升而進一步提高元件效率。此階段實驗分別製作兩組元件，分別為使用原本玻璃基板的對照組及更改為散射層基板的實驗組使用散射層基板後，不但抑制了對照組元件的共振腔效應，使頻譜更加穩定，在效率方面也隨著元件整體出光的上升，得到顯著的提升，最高外部量子效率達23.7%，功率效率為81.2 lm/W。

關鍵字

有機 ； 黃光 ； 銥金屬錯合物 ； 固態

並列摘要

In recent years, organic light-emitting diodes (OLEDs) have been widely studied for lighting and display applications due to their high contrast, wide viewing angle and low power consumption. Solid-state light-emitting electrochemical cells (LECs) based on ionic transition-metal complexes (iTMCs) have lower operating voltage than typical small-molecule OLEDs due to electrochemical doping. In addition, the solution-processable LECs have the potential in large-area displays.
This thesis will be divided into three parts in optimizing electroluminescence (EL) efficiency of the LECs based on the yellow-emitting ionic iridium complex [Ir(bppz)2(BPhen)]+(PF6-), where bppz is Butylphenylpyrazole and BPhen is 4,7-Diphenyl-1,10-phenanthroline. Firstly, the device thickness is optimized to reach the highest device efficiency. The peak external quantum efficiency (EQE) and power efficiency is 13% and 34.3 lm/W, respectively.
Secondly, the blue-emitting ionic iridium complex [Ir(dfppz)2(dmbpy)]+(PF6-), where dfppz is 1-(2′,4′-difluorophenyl)pyrazole and dmbpy is 4,4'-dimethyl-2,2'-bipyridine, is used for the host material for doping of the guest complex [Ir(bppz)2(BPhen)]+(PF6-). By adjusting the doping concentration, the highest EQE and power efficiency of 16.6% and 56.2 lm/W, respectively, can be obtained in the optimized host-guest LECs.
Thirdly, a composite substrate containing an embedded diffusion layer is utilized to further improve the device efficiency of the optimized host-guest LECs. With the diffusive substrate, the peak EQE and power efficiency can be further enhanced to 23.7% and 81.2 lm/W, respectively. Furthermore, the EL spectrum becomes more stable since the microcavity effect in the control device without a diffusive substrate can be destroyed in the LEC with a diffusive substrate.

並列關鍵字

Solid-State ； Yellow ； Light-Emitting Electrochemical Cells

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