物理汽相沉積法成長 Alq3 薄膜及其物理特性之探討

Growth and Characterization of Alq3 Films by Physical Vapor Deposition.

詹大正(Da-Jeng Jan)

指導教授 ： 邱寬城

中原大學/理學院/物理研究所/碩士(2011年)

https://doi.org/10.6840/cycu201100054

摘要

本實驗利用物理汽相沉積法 (Physical vapor deposition, PVD)，藉由固定粉末端溫度 (Tsou = 280℃)，調控基板端溫度 (Tsub = 60 ~ 180℃)、成長時間 (τ = 1 ~ 80 h)，製備不同形貌和厚度的 Alq3 多晶薄膜。由掃描式電子顯微鏡 (Scanning electron microscope, SEM) 觀測薄膜表面形貌與厚度，可觀察到 ITO 基板上先形成一層非結晶性薄膜且表面有一些成核的結構，而多壁管狀結構再由這些成核的結構繼續堆疊而成。由 X-ray 繞射 (X-ray diffraction, XRD) 分析薄膜之結晶相與結晶性，可觀察到此多壁管狀結構為 α-Alq3。經過分析各溫度點的成長速率與 Tsub 的關係圖 (Arrhenius plot)，可估算所對應的活化能。再由分析光穿透與光激螢光頻譜進而探討電子躍遷之模型，並決定能隙 Eg 大小，及其隨溫度之變化。最後由傅立葉轉換遠紅外線頻譜圖 (FT-IR) 分析得知此類晶體為 meridional 之同質異構物。

關鍵字

有機小分子 ； 物理汽相沉積法

並列摘要

In this study, various Alq3 films were grown from a physical vapor deposition system by controlling substrate temperature (Tsub= 60 ~ 180℃), source temperature (Tsou= 280℃), and growth time (τ = 1 ~ 80 h). The surface morphology and thickness of the Alq3 films were characterized by scanning electron microscopy (SEM). From the comparison of side-view and top-view SEM pictures, an Alq3 amorphous layer over an ITO-substrate was observed, then, an Alq3 tubular structure was found to be nucleated from this amorphous layer. From x-ray diffraction, the wetting layer exhibits an amorphous characteristic, while the Alq3 tubular layer possesses a triclinic α-phase structure. The growth behaviors of the tubular layer are studied in terms of the Arrhenius plot for this organic molecular solid formed by weak van der Waals interaction. From optical transmission and photoluminescence spectra, the optical properties of these Alq3 organic molecular films are discussed by using the energy terms diagram, and the temperature dependence of Eg is analysed. Finally, the Alq3 films deposited in this temperature range were confirmed to be mer-Alq3 by fourier transform infrared (FTIR) spectroscopy.

並列關鍵字

Alq3 ； Physical Vapor Deposition

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