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基于ZnO量子點的納米帶異質結可控制備與光學性能研究

發(fā)布時間:2018-04-24 23:01

  本文選題:ZnO量子點 + ZnO/CuO異質結構。 參考:《南昌航空大學》2015年碩士論文


【摘要】:本論文采用熱蒸發(fā)法成功制備出了ZnO/CuO量子點納米帶異質結、ZnO量子點/SnO2納米帶異質結材料。我們借助掃描電鏡(SEM)、X射線衍射(XRD)、透射電鏡(TEM)、能譜分析儀(EDS)對材料進行表征。借助拉曼光譜(Ramam)、光致發(fā)光(PL)、對材料進行光學性質研究。并對影響ZnO量子點在CuO納米帶上生長的條件,CuO納米帶的形貌控制、SnO2納米線的生長機制,ZnO/SnO2納米線的生長機制等多個問題進行了研究。1.ZnO/CuO納米帶點異質結的制備及光學特性研究我們首先通過熱蒸發(fā)法制備了CuO納米帶,找出了生長CuO納米帶的較優(yōu)條件。再把制備出的CuO納米帶浸泡在乙酸鋅溶液中,使乙酸鋅薄膜包裹在CuO納米線上,待干燥后放入管式爐中退火得到樣品。經(jīng)過改變不同條件后的多次實驗,并把制備的樣品通過XRD、FESEM和TEM進表征,我們發(fā)現(xiàn)了CuO納米線上可控生長ZnO量子點的較佳條件為450℃,乙酸鋅濃度0.37mol/L,氣體流量200sccm,分解時間3h。在這幾個條件下比較適合ZnO量子點在CuO納米線上生長,且量子點在CuO納米帶上分布均勻,ZnO量子點的尺寸大約5-10nm,長出了比較理想的ZnO/CuO納米帶異質結構。拉曼光譜(Ramam)測量發(fā)現(xiàn)在297.6cm-1、345.7cm-1、630.5cm-1、附近存在相應的拉曼頻移峰。其中,297cm-1處的拉曼頻移峰是單斜晶體CuO的特征峰,對應單斜相A2/B2的晶格振動模式,345.7cm-1處的拉曼峰是ZnO量子點對應的A1/E1縱向(LO)模,630.5cm-1處的拉曼振動是紅外活性模式,對應著氧缺陷激發(fā)發(fā)光模式。2.熱蒸發(fā)法制備ZnO/SnO2量子點/納米帶及其光學特性研究采取二步法在SnO2納米帶上浸泡乙酸鋅,再退火加熱得到ZnO/SnO2量子點/納米帶異質結,通過PL和Ramam研究了純SnO2納米帶、ZnO/SnO2量子點/納米帶的光學性能。發(fā)現(xiàn)純SnO2納米帶的PL譜的兩個卷積子帶分別位于613nm、727nm。SnO2/ZnO異質結構的PL譜通過高斯擬合后,兩個卷積子帶分別位于636.6nm,840.8nm。這是由于ZnO量子點改變了SnO2納米帶的帶隙,發(fā)生了紅移現(xiàn)象。
[Abstract]:In this paper, ZnO/CuO quantum dots / Sno _ 2 nanoscale heterojunction materials were successfully prepared by thermal evaporation method. The materials were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The optical properties of the materials were studied by Raman spectra and photoluminescence (PL). The growth mechanism of ZnO / Sno _ 2 nanowires and the growth mechanism of ZnO / Sno _ 2 nanowires were studied. 1. Preparation and optics of ZnO / CuO nanobelts heterojunction First, we prepared CuO nanobelts by thermal evaporation. The optimum conditions for the growth of CuO nanobelts were found out. Then the prepared CuO nanobelts were immersed in zinc acetate solution, and the zinc acetate film was coated on CuO nanowires. After drying, the samples were annealed in a tube furnace. After several experiments under different conditions, and the samples were characterized by TEM and FESEM, we found that the optimal conditions for the controllable growth of ZnO quantum dots on CuO nanowires were 450 鈩,

本文編號:1798631

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