本論文旨在研究高分子發光二極體的電性與光學特性，在高分子發光二極體中，隨著不同注入結構與各層模之間不同厚度的搭配，通常會影響發光效率與光譜，因此，本研究使用PPV 衍生物Super Yellow (SY) 作為發光層、ZnO:PEI作為電子注入層並改變兩者的實驗參數與厚度，觀察高分子發光二極體的外部量子效率，最終以ZnO:PEI為1:0.33、SY 為75 nm製作出發光效率為4.14 %的PLED，並藉由電性與光學分析探討影響元件效率高低的原因。 由實驗結果表明，SY PLED 中電洞傳輸效率高於電子傳輸效率，在電子注入層ZnO:PEI 摻入適當比例PEI於ZnO有助於降低電子注入能障至0.1 eV，同時可阻擋電洞並增加電洞於ZnO/SY界面處的累積，進一步幫助電子注入與電洞在SY復合發光。此外，實驗結果表明，當摻入過多的PEI時會導致薄膜表面的電阻值與粗糙度提升，同時，我們藉由Macleod軟體模擬PLED的內部電場分布並分析之，同時也探討PLED中的光學損耗模態。 ;This study aims to discuss the electrical and optical properties of organic light-emitting diode (PLED). In general, the layer thicknesses and injection structures of an PLED may influence the emission efficiency and output spectrum. In this study,we use the PPV derivative , Super Yellow, as the emitter layer, and ZnO:PEI as the electron injection layer, and measure the external quantum efficiencies (EQEs) of the PLEDs as a function of electron injection structures and SY layer thicknesses, we fabricate a PLED with external quantum efficiency 4.14% by using ZnO:PEI for 1:0.33 and SY for 75 nm. We then discuss the results of the different EQEs through the electrical and optical analyses. Our result shows that the hole transport is much more efficient than electron transport in an SY PLED. ZnO:PEI is an nano-composite structure, and an appropriate PEI ratio in the ZnO layer can reduce the electron injection barrier while blocking holes and increasing hole accumulations at the ZnO/SY interface, further facilitating the electron injection and recombination with holes in SY. Furthermore, we use the Macleod optical software to simulate and analyze the electric field distribution within the PLEDs, and also discuss the optical losses modes in the PLED structure, from which the influence of the SY thickness on the emission properties is explained.
