[[alternative]]The study in using black film to improve the contrast ratio of organic light emitting diode

碩士機電工程學系[[abstract]]隨著在國內、外各大廠商所開發出的OLED(有機發光二極體)，不論是亮度、電流效率、壽命或驅動電壓等，都有不斷提升突破的成果發表，OLED儼然已成為下一代面板的要角。 本研究以氧電漿微波功率120 W轟擊陽極ITO表面，處理時間在90 sec時，獲得ITO表面最佳均方根粗糙度2.60 nm及水滴接觸角8.05度。再以熱蒸鍍的方式，在有機腔體中蒸鍍有機材料NPB、Alq3及金屬腔體蒸鍍LiF並搭配Al/CuPC/Al/CuPC、CuPC/Fe2O3及CuPC/CuO等三種結構製成黑膜，成為有機發光二極體(OLED)中的複合式陰極，大幅地提高OLED元件之對比度。 研究結果顯示，標準反射鏡反射環境光源亮度在33.5 cd/m2的條件下，以Al/CuPC/Al/CuPC黑膜結構的OLED元件，厚度依序為4 nm/40 nm/4 nm/40 nm時，元件亮度可達4800 cd/m2，反射環境光的亮度為2.61 cd/m2，可獲得最高對比度1840；以黑膜結構的OLED元件，厚度依序為50 nm/60 nm時，元件亮度可達4110 cd/m2，反射環境光的亮度為4.49 cd/m2，最高對比度為916；以CuPC/CuO黑膜結構的OLED元件，厚度依序為30 nm/40 nm時，元件亮度最高亮度可達2060 cd/m2，反射環境光的亮度為8.09 cd/m2，最高對比度為256。而在無黑膜的一般元件中，最高亮度雖然達11000 cd/m2，但反射環境光的亮度有30 cd/m2，所能展現的最高對比度只有362。[[abstract]]This study in using 120 W micro wave power of oxygen plasma to bombard the ITO surface for 90 sec and got the best root mean square roughness 2.60 nm and water contact angle 8.05 degrees。 In sequential process, deposited NPB, Alq3 in organic chamber and LiF which collocates three kinds of black film Al/CuPC/Al/CuPC, CuPC/Fe2O3, CuPC/CuO separately being complex cathode electrodes in metal chamber by thermal vacuum vapor deposition process. And those three kinds of black film do increase the contrast ratio of OLED device largely. The experiment resulted that the brightness of OLED device which made by Al/CuPC/Al/CuPC in 4 nm/40 nm/4 nm/40 nm thickness is 4800 cd/m2. And the brightness of reflected ambient light is 2.61 cd/m2 by Al/CuPC/Al/CuPC black film when the luminance is 33.5 cd/m2 reflected from standard mirror. In the same ambient light luminance the black film of OLED is made by CuPC/Fe2O3 in 50 nm/60 nm thickness which let device have 4110 cd/m2 luminance and the reflected ambient light brightness is 4.49 cd/m2 and the contrast ratio is 916. The last black film structure of OLED is CuPC/CuO in 30 nm/40 nm thickness. In this device presented 2060 cd/m2 luminance, the reflected ambient light brightness is 8.09 and the contrast ratio is 916. And compare the non-black film structure device, the highest brightness is 11000 cd/m2. But as the reflected ambient light brightness is 30 cd/m2 so the highest contrast ratio is only 362