建立於負偏壓下有機發光二極體之亮度劣化模型以應用於AMOLED畫素電路

Abstract

有機發光二極體(Organic light emitting diode；OLED)被視為繼液晶顯視器(Liquid crystal display；LCD)後，未來最具發展潛力的平面顯示技術之ㄧ，其受到青睞的原因為除了具有主動發光、高應答速度特性、高對比、省電、廣視角、低操作電壓、面板輕薄等優點外，另有製程簡單低成本、可應用於可繞式面板等特色，因此OLED號稱為最理想的顯示器之一。然而，目前無法投入大量生產之主要原因在於OLED元件劣化，其劣化原因為OLED在固定電流密度通過下產生之元件劣化效應。本論文為驗證新型對偶畫素電路[1]之功效，此對偶畫素電路其主要優點為減少畫素面積來提高OLED面板解析度以及施予OLED元件負偏壓來改善OLED亮度劣化。透過layout結果可以驗證此對偶畫素電路是具有相當高的面板解析度；再經由友達光電股份有限公司幫忙下線，完成欲進行測試之製程品製作；接著進行實際的實驗量測，由實驗量測的結果來驗證此對偶畫素電路產生之負偏壓的確可以改善OLED的亮度劣化。最後建立於負偏壓下之亮度劣化模型，利用軟體模擬負偏壓改善亮度劣化之效果，並將模擬結果與實際量測結果做比較。另外，亮度劣化模型也可應用於在亮度補償後的OLED亮度劣化模擬。

An organic light emitting diode (OLED) display has been as an ideal display for next generation after liquid crystal display (LCD), since it has many advantages, such as high brightness, high efficiency, wide viewing angle, simple structure, low cost, high response speed (1 us), very thin and very flexible. However, the OLED display cannot be invested a lot of production mainly due to an OLED component degradation. The thesis verifies efficacy of novel dual-pixel circuit [1]. Main characteristics of this dual-pixel circuit are reducing pixel area for raising OLED panel resolution and giving an OLED component reverse biases to alleviate OLED luminance degradation. Layout results can verify that the dual-pixel circuit has high panel resolution. AU Optronics Corp helps chip fabrications. The dual-pixel circuit is fabricated for performance testing. Experimental measurement results can verify that reverse biases of the dual-pixel circuit can indeed alleviate OLED luminance degradation. Finally, an OLED emission model under reverse biases is established. The software is used to simulate effects of alleviating OLED luminance degradation. Simulation results are compared to measurement results. The OLED emission model under reverse biases also can be used to simulate OLED luminance degradation after luminance compensation.