基于ZnO量子点的纳米带异质结可控制备与光学性能研究

发布时间：2018-04-24 23:01

  本文选题：ZnO量子点 + ZnO/CuO异质结构　； 参考：《南昌航空大学》2015年硕士论文

【摘要】：本论文采用热蒸发法成功制备出了ZnO/CuO量子点纳米带异质结、ZnO量子点/SnO2纳米带异质结材料。我们借助扫描电镜(SEM)、X射线衍射(XRD)、透射电镜(TEM)、能谱分析仪(EDS)对材料进行表征。借助拉曼光谱(Ramam)、光致发光(PL)、对材料进行光学性质研究。并对影响ZnO量子点在CuO纳米带上生长的条件,CuO纳米带的形貌控制、SnO2纳米线的生长机制,ZnO/SnO2纳米线的生长机制等多个问题进行了研究。1.ZnO/CuO纳米带点异质结的制备及光学特性研究我们首先通过热蒸发法制备了CuO纳米带,找出了生长CuO纳米带的较优条件。再把制备出的CuO纳米带浸泡在乙酸锌溶液中,使乙酸锌薄膜包裹在CuO纳米线上,待干燥后放入管式炉中退火得到样品。经过改变不同条件后的多次实验,并把制备的样品通过XRD、FESEM和TEM进表征,我们发现了CuO纳米线上可控生长ZnO量子点的较佳条件为450℃,乙酸锌浓度0.37mol/L,气体流量200sccm,分解时间3h。在这几个条件下比较适合ZnO量子点在CuO纳米线上生长,且量子点在CuO纳米带上分布均匀,ZnO量子点的尺寸大约5-10nm,长出了比较理想的ZnO/CuO纳米带异质结构。拉曼光谱(Ramam)测量发现在297.6cm-1、345.7cm-1、630.5cm-1、附近存在相应的拉曼频移峰。其中,297cm-1处的拉曼频移峰是单斜晶体CuO的特征峰,对应单斜相A2/B2的晶格振动模式,345.7cm-1处的拉曼峰是ZnO量子点对应的A1/E1纵向(LO)模,630.5cm-1处的拉曼振动是红外活性模式,对应着氧缺陷激发发光模式。2.热蒸发法制备ZnO/SnO2量子点/纳米带及其光学特性研究采取二步法在SnO2纳米带上浸泡乙酸锌,再退火加热得到ZnO/SnO2量子点/纳米带异质结,通过PL和Ramam研究了纯SnO2纳米带、ZnO/SnO2量子点/纳米带的光学性能。发现纯SnO2纳米带的PL谱的两个卷积子带分别位于613nm、727nm。SnO2/ZnO异质结构的PL谱通过高斯拟合后,两个卷积子带分别位于636.6nm,840.8nm。这是由于ZnO量子点改变了SnO2纳米带的带隙,发生了红移现象。
[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，

本文编号：1798631