單層及雙層發光層有機發光二極體模擬

Abstract

我們專注於模擬具有雙發光層結構的有機發光二極體。因為模擬的有機發光二極體的發光層具有三重態-三重態融合和高能量傳輸率的特點，因此可以實現高量子效率。為了能完整地模擬發光層中單重態和三重態激子的物理機制和發光機制，我們採用了多種公式和方法，經過不斷的修正和與實驗數據的比較，最終得到了一個與實驗數據吻合的完整模型。在雙層發光層的裝置中，電子電洞在DMPPP為主體DPaNIF為客體的發光層複合，產生單重態激子跟三重態激子，單重態激子直接放光，三重態激子則是流到隔壁以NPAN為主體DPaNIF為客體的發光層進行三重態-三重態融合，生成單重態激子隨即放光，因為有單重態激子的直接放光，又有三重態-三重態融合生成單重態激子進行延遲放光，因此雙發光層裝置的效率比單發光層裝置還要好。影響三重態-三重態融合的關鍵因素為電子電洞與三重態激子之間的交互作用，隨著電壓加大，電子電洞與三重態激子間的交互作用也越發劇烈，因此模擬的雙發光層裝置的效率離理想狀態的62.5%還有一段差距，未來還有挑戰需要克服。

We focus on simulating organic light-emitting diodes (OLED) with a double-emitting layer (EML) structure. Because the EML of the simulated OLED is characterized by triplet-triplet fusion (TTF) and a high energy transfer rate, high quantum efficiency can be achieved. To completely simulate the physical and light-emitting mechanisms of singlet and triplet excitons in the EML, we adopted a variety of formulas and methods. After constant revision and comparison with the experimental data, we finally obtained a consistent with the experimental data—complete model. In the double-EML device, electrons and holes recombine in the EML with DMPPP as the host and DPaNIF as the guest to generate singlet excitons and triplet excitons. The singlet excitons emit light directly. The triplet excitons flow to the EML with NPAN as the host and DPaNIF as the guest for TTF to generate singlet excitons and then emit light. Because of the direct emission of singlet excitons, TTF generates an extra singlet exciton. Furthermore, the excitons perform delayed emission, so the efficiency of the double-EML device is better than that of the single-EML device. The interaction between electron holes and triplet excitons is critical to TTF. As the voltage increases, the interaction between electron holes and triplet excitons becomes more intense. Therefore, the simulated efficiency of the double-EML device is still a long way from the ideal 62.5%, and there are still challenges to be overcome in the future.