Polymer White Light Emitting Diode based on phosphorescent dopant

• Main Authors: Shu-Chia Hsu, 許書嘉
• Other Authors: Yan-Kuin Su
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/28053526083282124876

碩士 === 國立成功大學 === 光電科學與工程研究所 === 94 === 　　By the development of the intelligent industry, people have more require for the monitor. Although the CRT is low-cost and good image quality, the CRT is too big and too heavy. Therefore, the new flat panel displays (FPD) have to be thinner and lighter. In this age, polymer light-emitting diodes (PLED) that are based on conjugated polymers have attracted much attention because of their potential applicability to large-area flat panel displays (FPD). Because polymeric materials are known to be sensitive, therefore, various approaches have been explored to improve the device efficiency and luminescence. In this work, an effect of thermal treatment before cathode deposition and post cathode deposition are presented for the purpose of achieving high efficiency Polymer light - emitting diodes by change the roughness and the chain intensity. 　　At first, the devices had been made as ITO/PEDOT:PSS /FIrpic&Ir(btp)2(acac)&PBDorTPD/Ca/Al. The PEDOT: PSS served as HTL, and FIrpic and Ir(btp)2(acac) served as phosphorescent materials. The white emission was tuned the ratio between FIrpic and Ir(btp)2(acac). The PVK was belonging to p-type material. If I wanted to increase the exciton, to increase the injections of the electrons and holes was must. The dopants were TPD and PBD. 　　The most difficulty of all was the modulation of the accurate weight-ratio. The energy-transfer of Ir(btp)2(acac) from host was very good. The intensity of the red peak was serious when the quantity of dopant was a little. Finally the CIE coordinate closest to white emission was (0.34, 0.37). In order to increase the ability of recombination, to dope PBD and TPD was necessary. After that, I found the TPD was useless in my system. The PBD could increase the performance of my device indeed. And the maximum luminance and efficiency were 3100 Cd/m2 and 1.8 Cd/A.