高度比度顯示元件之研究

• Main Authors: 邱天隆, Chiu, Tien-Lung
• Other Authors: 李君浩, Lee, Jiun-Haw, 臺灣大學:光電工程學研究所
• Format: Thesis
• Language: English
• Published: 2009
• Subjects: 有機發光二極體;低反射;吸光性; organic light emitted diode;low reflection;absorption; DML
• Online Access: http://ntur.lib.ntu.edu.tw/handle/246246/188464; http://ntur.lib.ntu.edu.tw/bitstream/246246/188464/1/ntu-98-D93941006-1.pdf

本論文中將介紹兩種高對比度顯示元件。其一為內含黑色陰電極的有機發光元件(OLED)，另一種為利用反射式液晶顯示元件(RLCD)與透明OLED元件垂直整合並封裝成一個單一混成元件。新的黑色陰極的OLED內含有破壞性干涉的共振腔結構，共振腔中所填充的介電層為一具有高吸收特性與高導電特性。介電層的材料是利用銀粒子摻雜有機材料MPPDI而來。有機材料吸收的增強與導電性的增加主要分別來自奈米銀離子的摻雜所造成的表面電漿共振所引發的吸收增強與銀本身電性較佳的結果。未做表面抗反射處理的黑色陰電極的OLED所導致的反射超低大約只有4%，這個值很接近空氣與玻璃介面的反射；在人眼最敏感的波長550 nm部份，也只有5.5%。此元件在廣視角的影像表現很好，反射率也很低，在斜視角60o時有反射率12.3％在550 nm，因此有利於當成手持顯示裝置在戶外使用。再者，此元件的電性與壽命表現也與一般傳統元件相當。造中結合兩種不同元件RLCD與透明OLED具有相當困難度，我們發展了一套適當的製造流程設計以使得OLED的光電特性不受製程影響。在元件的儲存狀態下壽命測試中，可發現透明OLED在此混成元件中可以保有比傳統封裝方式的元件還久的特性，原因來自於液晶也形成另一型式的保護層保護著OLED。 In this thesis, two kinds of high contrast display devices were demonstrated. One is an organic light-emitting device (OLED) with absorptive and destructive interference black cathode (ADIBC) structure. The other is a hybrid device vertically integrated with a reflective liquid crystal display (RLCD) and a transparent OLED in one unit cell.he novel ADIBC-OLED constructed with a destructive interference cavity filled with a highly absorptive and conductively thin-film which was fabricated by doping Ag into N,N''-Bis (2,6-diisopropylphenyl)-1,7-bis (4-methoxy-phenyl) perylene-3,4,9,10 -tetracarboxydiimide (MPPDI). Strong absorption and high conduction of thin-film resulted from plasmon-enhanced absorption and electrical properties improvement of Ag nanoparticles. Reflection from the ADIBC-OLED is as low as 4% at 800 nm, and 5.5% at 550 nm. Besides, low reflection was also achieved at oblique viewing angles (12.3% at 550 nm with 60o) with good image quality under outdoor environments. Such a ADIBC-OLED exhibited a nearly identical J-V and lifetime performances to the control device.abrication and integration issues of the transflective (TR-) hybrid device consisting of a reflective LCD and an OLED were addressed and solved. With suitable design of the process flow, electrical and optical characteristics of the OLED were not affected by the following LCD processes. Storage lifetime of this TR-hybrid device was even longer than that of the control one because of the passivation effect of the LC materials. Contents 要 ibstract iiontents ivable captions: viiigure captions: viiihapter 1 1.1 Contrast ratio (CR) and ambient contrast ratio (A-CR) of a display 3.2 Introduction to OLED and LCD 5.2.1 Organic light-emitting device 6.2.2 Liquid crystal display 8.3 High ambient contrast OLED 11.4 Hybrid Emi-flective device (OLED combined with LCD) 15.5 Thesis organization 18eference 23hapter 2 27.1 Introduction 27.2 Fabrication of OLED 28.2.1 Evaporator 28.2.2 OLED and monolayer device 29.3 Measurement of organic thin film and OLED 31.3.1 B-J-V characteristics of OLED, J-V of organic thin film, and photocurrent measurements 31.3.2 Optical measurements: PL, Transmittance and Reflectance 33.3.3 Morphological measurements (FE-SEM, AFM, SOPRA) 35.4 LCD fabrication and measurements 36eferences 45hapter 3 46.1 Introduction 46.2 Ag Dopant 49.2.1 Appearance of thin-films 49.2.2 Morphology: FE-SEM and AFM 50.2.3 Optical properties: refractive index n(λ) and absorption coefficient k(λ) 52.2.4 Optical analysis: transmittance, reflectance and absorptance 53.2.5 Photoluminescence characteristics 56.2.6 Electrical characteristics of mono-layer device 58.2.7 Photosensitivity 60eference 74hapter 4 76.1 Introduction 76.2 Results of A series 77.2.1 Architecture of ADIBC-OLED 77.2.2 Results and discussions 78.3.1 Architecture and fabrication 82.3.2 Results and discussions 83.3.3 Results and discussion for A-CR and wide view angle reflectance 87eference 110hapter 5 111.1 Introduction 111.2 Experimental details (fabrication for transparent OLED and the TR-hybrid device) 113.2.1 Transparent OLED fabrication 113.2.2 Fabrication process for TR-hybrid device 113.3 Results and discussions 116.3.1 Characteristics of DML for transparent OLED 116.3.2 Variation of transparent OLED characteristics during fabrication 116.3.3 Optical characteristics of TR-hybrid device 118.4 Operational mechanism and Storage lifetime for hybrid device 121eference 132hapter 6 133.1 Summary 133.2 Further works 135eference 138ppendix A 139.1 Introduction: 139.2 Organic material: 141.2.1 Chemical structure 141.2.2 Absorptance spectrum 143.3.1 Absorption characterizations 144.3.2 Photoluminescence 144.3.3 Photocurrent measurement 146eference 152ppendix B 153eference 158ppendix C 159eference 165ppendix D 166.1. High transparent OLED structure and characterization 167.2. Conceptual structure of tandem device 168.3 Simulated A-CR results 169.4 Operational mechanisms and white light A-CR 172eferences 178