量子點已被廣泛運用於生物醫學、發光二極體、太陽能電池以及光感測器。量子點的優點包含了能隙可調變性、高量子效率和高色彩飽和度，這些優勢讓量子點發光二極體在近年來引起關注，使得量子點發光二極體極為可能成為下一代顯示技術的主流。
然而電荷注入不平衡造成量子點發光二極體之電特性下降。本研究提出藉由摻入發光材料(DDCzTrz、PVK)於量子點發光二極體中，利用過量注入的電子於發光材料中和電洞結合形成激子，再藉由福斯特能量共振轉移將激子能量傳遞給鄰近的量子點，其減緩電子堆積並提升元件效率。除此之外，發光材料摻入電洞傳輸層或發光層亦可降低薄膜表面形貌粗糙度而有助於電洞的注入。
供體和受體分子間的距離對於福斯特能量共振轉移有高度依賴性。因此本實驗中DDCzTrz各別摻入電洞傳輸層和發光層以探討其對元件特性的影響。PVK取代DDCzTrz摻入於發光層中可顯著地增加薄膜均勻性。PVK的摻入使元件效率更進一步的提升。而將DDCzTrz摻入電洞傳輸層和PVK摻入發光層同時提升電洞傳輸層和發光層的薄膜均勻性，且增加能量轉移機率。此結構得到最佳的特性，其亮度為每平方公尺200021燭光，電流效率為每安培14.3燭光。

Quantum dots (QDs) have been widely used in biomedical applications, light-emitting diodes (LEDs), light detection and solar cells. The advantages of QDs include tunable bandgap, high photoluminescence quantum yield and color-saturated emission, making quantum dot light emitting diodes (QD-LEDs) a promising candidate for next generation display technology.
However, the unbalanced carrier injection between electrons and holes will result in the efficiency droop. In this research, the luminescent materials (DDCzTrz and PVK) are doped in QD-LEDs to solve this problem. If the electron leakage from emission layer can form excitons with the injected holes from the HTL, followed by energy transfer from the TADF material to the adjacent QDs, the electron accumulation can then be alleviated, and simultaneously the performance can be improved. Additionally, the involvement of luminescent materials doped in hole transport layer or emission layer can smoothen the surface roughness and improve the hole injection.
The FRET efficiency highly depends on distance between donor and acceptor in an exciton. As a result, DDCzTrz is doped in HTL and EML to investigate the effect on device characteristics firstly. Later, DDCzTrz is replaced with PVK because PVK can significantly improve the surface morphology and the QD-LED performance can further be improved. Finally, the DDCzTrz and PVK are respectively added into HTL and EML for reduce surface roughness and increase energy transfer rate. The highest luminance of 20021 cd/m2 and current efficiency of 14.3 cd/A are obtained from this structure.

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