三重態融合有機發光二極體之模擬及優化

Abstract

本論文利用實驗室開發的1D-DDCC軟體，模擬具有不同發光層材料的TTF-OLED裝置，其中模擬軟體考慮了高斯能態密度及field-dependent載子遷移率，以更完整呈現有機材料的電特性，亦包含同時考慮單重態及三重態激子的激子擴散模型，並有效模擬新一代OLED元件的性質。透過軟體我們計算TTF-OLEDs之電流密度-電壓曲線、內部量子效率及TREL頻譜等特性，及分析造成TTF-OLEDs效率產生損耗的原因，發現在hyper-TTF-OLEDs當中，嚴重的三重態激子-極化子熄滅效應會導致三重態融合效應減弱，並降低元件效率表現。在單發光層non-TTF-OLEDs當中，較弱的三重態激子-極化子熄滅效應將會帶來嚴重的三重態激子-單重態激子湮滅效應，導致效率下降。而藉由討論發光層之能帶結構、載子遷移率及激子擴散等性質，我們總結出幾項能讓TTF-OLEDs效率優化的方法，並在最後章節，透過這些論點比較具有不同發光層材料DMPPP，DCPPP和PPC之TTF-OLEDs的表現差異。

In this research, we utilize the 1D-DDCC solver developed in our laboratory to simulate TTF-OLED devices with different emissive layer materials. The simulation solver includes the Gaussian density of states and field-dependent carrier mobility to comprehensively analyze the electrical properties of organic materials. It includes a model that considers both singlet and triplet exciton diffusion and effectively simulates the performance of the next-generation OLED devices. We calculate various properties of TTF-OLEDs, such as current density-voltage curves, internal quantum efficiency, and TREL spectrum, and analyze the reasons for efficiency losses in TTF-OLEDs and identify that in hyper-TTF-OLEDs, severe triplet-polaron quenching weakens the triplet-triplet fusion effect, leading to reduced device efficiency. In non-TTF-OLEDs with a single emissive layer, weaker triplet-polaron quenching results in significant triplet-singlet exciton annihilation, causing the efficiency decrease. By investigating the band structure, carrier mobility, and exciton diffusion properties of the emissive layers and summarizing several methods for optimizing the efficiency of TTF-OLEDs. In the final section, we compare the performance differences of TTF-OLEDs with different emissive layer materials: DMPPP, DCPPP, and PPC.