以畫素分區與中空排列微透鏡陣列促進有機發光元件效率

Abstract

本篇論文目的是為了增加有機發光元件的外部發光效率，採取貼附微透鏡陣列的方法，以破壞玻璃基板與空氣之間的全反射。我們提出使用中空式排列的新型微結構，並且結合畫素分區的方式，可應用在指向性照明用的面板上，例如桌燈；並可搭配使用補助電極以增進電流傳導特性。 我們是以數值模擬進行相關的研究，使用光學軟體 LightTools 進行光線追蹤模擬，並藉由系統性的進行參數調整，如子畫素面積、子畫素週期、以及微透鏡的高徑比，來探討其對於元件的功率以及正向亮度的影響。 從我們的模擬結果得知，在不加補助電極的情況下，畫素分區成子畫素面積 100 μm × 100 μm，使用中空式的微透鏡排列，將可以改善畫素未分區時的效率，使正向亮度達到 58.6 %；加上補助電極之後，為了避免畫素發光被補助電極擋住，使用畫素分區的方式分成子畫素面積 104 μm × 104 μm，並且用中空式的微透鏡排列，可以得到正向效率隨著補助電極覆蓋率增加而提升，補助電極覆蓋率53.76 % 時，正向效率提升 48 %。

We demonstrate a simulation model of OLED by utilizing ray-tracing with the optical software LightTools. Applying the microlens array film (MAF) is the way to reduce the total internal reflection (TIR) between air and glass interfaces. Furthermore, in order to improve optical characteristics of devices and also have the potential for longer lifetime, partitioning pixel incorporate hollow-arranged MAF with auxiliary electrodes was proposed. We modulate some parameters such as area and period of sub-pixel, and aspect ratio of MAF which to find out the effects on total power enhancement and 0° luminance enhancement compared to bare device. In our simulation results, partitioned devices with hollow-arranged MAF can have vastly improvement to 58.6 % under the same total active area and optical power generated by the organic emitter. However, applying auxiliary electrodes could shield rays from the organic emitter, partitioning pixel assisted with hollow-arranged MAF seems to be a good choice and 0° luminance enhancement will be promoted to 48 %.