The electro-optical characteristics of polymer light-emitting devices by incorporating Au nanoparticles in luminescent polymer

• Main Authors: Sung-Nien Hsieh, 謝松年
• Other Authors: Ten-Chin Wen
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/68755456785459228674

博士 === 國立成功大學 === 化學工程學系碩博士班 === 95 === In this dissertation, the effects and application of incorporating a small amount of Au nanoparticles into a luminescent polymer are investigated. The contents include two parts: This first section reports the luminescent and electric properties of phenyl-substituted poly(para-phenylene vinylene) copolymer (HY-PPV) in which Au nanoparticles were incorporated. Incorporating a small amount of Au nanoparticles into HY-PPV film increases the electroluminescence (EL) efficiency and the operating voltage of HY-PPV-based polymer light-emitting diodes (PLEDs) using Al as cathode. These unique behaviors are due to the increase in the density of the effective hole trap centers. In addition, the device performance is found to strongly depend on both the Au nanoparticle/HY-PPV volume ratio and the difference between the work function of Au nanoparticles and the highest occupied molecular orbital (HOMO) of the luminescent polmer. In second section, an efficient top-emissive polymer light-emitting diode (T-PLED) employing Ag as a semitransparent cathode is achieved by adding Au nanoparticles to HY-PPV. The efficiency of the T-PLED with Au nanoparticles is 3.4 cd/A, which is much higher than that of the T-PLED without such particles (0.15 cd/A). The superior performance of the device is attributed to the balance between the electron and hole currents induced by the Au nanoparticles, which increases the probability of hole-electron recombination. Furthermore, the device’s stability in air can be significantly improved because of the use of stable electrodes.