Study on the Structure Design and Process Development of Organic Light-Emitting Diodes

• Main Authors: Wei-Lin Lai, 賴韋霖
• Other Authors: Jian-Yang Lin
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/81435966345091081026

碩士 === 國立雲林科技大學 === 電子與資訊工程研究所 === 93 === This paper is making a study of organic light emitting diodes (OLED) process and techniques. Forces on the small molecule organic light emitting diodes. To use sputtering technology making transparent conductive thin films and evaporator technology making organic thin films. The sputtering fabrication technology to grow up the indium tin oxide (ITO) thin films substrate that necessary for anode of the OLED devices and the evaporating fabrication technology. To investigate the factors of the sputtering fabrication parameter for the analysis of characteristic grow up ITO transparent conductive thin films. Including influences of the thin films electric conductivity, optical transparent, and roughness for the sputtering parameters, such as power, working pressure, heating temperature, deposition time, etc. And investigate the property of ITO thermal process and pre-clean process. After sputtering finished and via the thermal and pre-clean process, ITO films sheet resistance can reduce reach 22Ω/□, visible light optical transparence is 78%, surface roughness 0.773nm. Finally, the ITO substrate will be finished by the optimization fabrication as OLED devices anode of follow-up investigation. In the follow up fabrication, major structure forces on double layer type of OLED, the material choose two kinds of most general green light materials of OLED, Alq3 material as electron transport and emission layer, NPB material as hole transport layer, and the Al metal is made for the device back electrode (Cathode). To investigate two kinds of materials that different thickness match influences on the OLED devices electro-optical characteristic, include the electroluminescence, current density, turn on voltage, luminance or brightness, EL Spectrum etc. With NPB : Alq3 = 50nm : 70nm condition, in applied voltage 15V, luminance reaches 486 cd/m2, current density 351A/m2 that the best luminance show and the turn on voltage as 6V also the supreme luminance and the lowest turn on voltage in this research. In this investigation, we expect to understand the organic display physical property and optimize fabrication conditions of the OLED and reach self-technology purpose.