以透明氧化物導體為基礎之透明有機發光二極體開發研究

Abstract

近年來，有機發光二極體的快速發展，成為重要的平面顯示與照明技術，其研究發展備受矚目，其中因為有機材料的透明性，使得透明有機發光二極體具有可行性，能有更廣泛的潛在應用。因此，有許多研究致力於發展透明有機發光二極體。有別於現行較為普遍的薄金屬電極元件研究，本論文將以研究透明導電氧化物電極為主軸，另外為了滿足高效率、低操作電壓、長壽命的顯示元件特性，我們必須設法了解透明元件的光學特性，來達到最佳的外部出光效率，並維持元件的高穿透度。在本論文的第一部分，我們針對透明導電氧化物的電極做製程上的測試，藉由調控濺鍍的功率，取得不同條件下的光學及電性特性，接著透過文獻回顧選擇適當的緩衝保護/電荷注入層，並與上電極搭配選擇最佳結構。在本論文的第二部分，我們說明了光學模擬所應用的原理，並透過此模型來預測能達到最佳外部出光效率的最佳結構及該結構下之穿透度。接著，我們實作出以透明導電氧化物為電極的透明有機發光二極體元件，將其實驗結果與模擬相比較，並推測與模擬結果有所出入的原因。

Nowadays, Organic light-emitting devices (OLEDs) have been demonstrated as an important display and lighting technology. Among various advantages, transparency of organic materials can further extend applications to transparent OLEDs. Therefore, many researchers have been devoted to developing transparent OLEDs. Different from many current researches using thin metal as transparent top electrodes, we focus on the transparent conducting oxides (TCOs) electrodes. Also, to achieve high efficiency, low operating voltage and long lifetime, we should understand the optical characteristics in transparent devices to optimize the external quantum efficiency and maintain high transparency.In the first part of this thesis study, we conducted tests on the deposition of TCO electrodes. By controlling the power of sputtering process, we studied the optical properties and electrical properties of TCOs made under different conditions. Then, suitable buffer protection/ injection materials were also studied together with the TCO electrode to form the effective transparent top electrode for transparent OLEDs. In the second part of this thesis study, we conducted both simulation and experiment studies on optical characteristics of transparent OLED structures using TCOs as transparent top electrodes to determine suitable structures for optimum external quantum efficiency and transmittance. Then, by comparing the experiments and simulation results, we analyzed the reasons that result in the difference between the simulation and the experiments.