摻雜對量子點發光二極體之影響

The Influence of Doping on Quantum Dot Light Emitting Diodes

蔡孟庭(Tsai Meng-Ting)

指導教授 ： 趙宇強

國立臺灣師範大學/理學院/物理學系/碩士(2020年)

https://doi.org/10.6345/NTNU202001269

摘要

本研究使用全溶液製程製備量子點發光二極體，並針對其中作為電洞注入層的poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)和作為電洞傳輸層的poly(9-vinylcarbazole) (PVK)進行摻雜。首先，先分別對各自層摻雜，研究單層摻雜對於元件效率的影響，並且從不同材料特性方面做摻雜前後分析比較。接著，研究同時對兩層摻雜。固定其中一層之摻雜濃度為可以得到最高效率的濃度，再去調整另一層的摻雜比例，以瞭解同時對兩層摻雜對元件效率之影響。
我們所製備的量子點發光二極體元件之材料分別為：ITO作為陽極材料；LiF、Al作為陰極材料；PEDOT:PSS做為電洞注入層；PVK作為電洞傳輸層；ZnO、PEIE作為電子傳輸層；而發光層量子點則使用熱門材料──紅光CdSe。我們在電洞注入層PEDOT:PSS中摻雜不同比例的編號P105分散劑；並且在電洞傳輸層PVK中摻雜TAPC。自兩層的摻雜比例中找到能使元件經過電致發光的元件效率達到最高數值的比例，並從光特質(光致發光譜、吸收光譜和穿透光譜)、表面形貌(AFM原子力顯微鏡)、材料電性改變(電流電壓圖)等方面對摻雜前後做比較分析。
最後我們從實驗結果分析中得到，在電洞注入層中摻雜P105使得電流密度下降，而在電洞傳輸層摻雜TAPC反而使電流密度上升，然而上升的幅度比PEDOT摻雜造成的下降幅度小，故在最後同時摻雜時整體的電流密度是下降的。而表面形貌也因為摻雜，粗糙度降低。最終我們由實驗可以得到在PEDOT:PSS中摻雜P105以及在PVK中摻雜TAPC確實能夠將量子點發光二極體的量子效率提高。

關鍵字

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並列摘要

In this research work, the quantum dot light-emitting diodes were prepared by all-solution-process and the influences of doping of the hole injection layer and the hole transport layer on the device performance were investigated. First, the influences of doping of the hole injection layer or the hole transport layer were investigated respectively. The properties of the undoped and doped materials were studied. Second, devices with both the doped hole injection layer and the doped hole transport layer were investigated. The doping concentration of the hole injection layer was varied while the one of the hole transport layer was fixed.
The quantum dot light-emitting diodes were prepared by using ITO as the anode, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as the hole injection layer, poly(9-vinylcarbazole) (PVK) as the hole transport layer, CdSe quantum dots as the emissive layer, ZnO as the electron transport layer, and LiF/Al as the cathode. P105 was doped into PEDOT:PSS, while 1,1-Bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) was doped into PVK. Photoluminescence spectra, absorption spectra, transmission spectra, atomic force microscope images, current-voltage curves were used to understand the influence of doping. It was found that by carefully control the doping concentration of P105 and TAPC, device performance con be improved.

並列關鍵字

none

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