微纳米花形ZnO的水浴法制备及其光学性能研究

发布时间：2018-03-14 09:18

本文选题：花形　切入点：氧化锌　出处：《中国海洋大学》2011年硕士论文　论文类型：学位论文

【摘要】：ZnO是一种重要的II-IV族直接宽禁带半导体材料,室温下禁带宽度为3.37 eV,激子束缚能高达60 meV,被认为是一种有广阔应用前景的紫外光发射材料。同时它也是一种多功能氧化物材料,在光电、铁电、压电、热电、铁磁等领域具有优异的特性,可广泛应用于透明电极、压电材料、压敏电阻、声波器件和太阳能电池等诸多领域。目前,ZnO的研究主要集中在ZnO薄膜、ZnO掺杂及ZnO纳米结构的研究。在纳米结构领域,科研人员已经取得了很大进展,但纳米ZnO器件的应用仍然任重而道远。众所周知,材料的性能取决于材料的结构,而材料的结构又很大程度上取决于制备方法和工艺。因此,对于材料的形貌、尺寸等的可控制备研究,对于纳米ZnO器件的应用是至关重要的前提。本论文采用简单的水浴法,以硝酸锌(Zn(NO_3)_2·6H_2O)、六亚甲基四胺((CH_2)6N_4)和乙二胺(C2H8N2)为原料,制备了微纳米花形ZnO结构,为研究其生长过程/原理,在不同实验条件(浓度、温度、时间、反应物配比)下制备了不同形貌的ZnO微纳米材料,系统探讨了不同因素对其形貌和结构的影响,并采用光致发光谱和紫外-可见光吸收光谱作为光学性能的表征手段。此外,以普通玻璃片为基底,采用一步水浴法制备出了微纳米花形ZnO阵列及掺S微纳米花形ZnO阵列,研究了掺S对花形ZnO阵列结构、形貌与发光性能的影响。采用X-射线粉末衍射仪(XRD)进行物相分析,场发射扫描电子显微镜(FESEM)透射电镜(TEM,配有选区电子衍射(SAED))观察产物的形貌,荧光光谱仪(激发光源为Xe灯)在室温下测定光致发光(PL)光谱,紫外光谱仪分析样品的紫外-可见光吸收光谱。研究结果表明: (1)微纳米花形ZnO的花瓣为六角锥形结构,XRD测试表明其为纤锌矿ZnO结构,高分辨透射电镜及选区电子衍射花样表明其为单晶结构,并且沿着从c轴生长,能谱分析表明其由Zn和O元素组成,组成接近1:1,表明其结晶良好。 (2)反应溶液浓度、生长温度、生长时间、反应物配比等对样品形貌的影响较大。随着反应溶液浓度的增大,微纳米花形ZnO的生长速度加快,尺寸增加,结晶致密、晶体质量提高。随着生长温度的降低,晶核易团聚从而导致花瓣聚集;此外温度的降低使反应速率降低,并导致晶粒发育不完全。随着生长时间的延长,初期有助于晶粒的发育和长大,但当时间过长时,容易造成“溶解”现象,使晶体质量下降。乙二胺的选择性吸附提供了二次形核生长点,因此在形成花形ZnO结构中起着决定性的作用,而六亚甲基四胺只是影响花瓣的形貌,吸附在花瓣侧面阻碍其生长,使花瓣更为“修长”。 (3)微纳米花形ZnO的PL谱中有两个特征发光峰,分别是365 nm处的窄的紫外发射峰及406 nm左右宽的紫外-紫光发光峰。不同反应条件(反应溶液浓度、生长温度、反应物配比)对光致发光性能亦有影响。 (4)掺S微纳米花形ZnO阵列较未掺微纳米花形ZnO阵列的均匀性和取向性得到了提高,但表面变得粗糙,此外,掺S后产物的PL光谱的UV发射峰减弱且出现了较强的绿光发射峰。
[Abstract]:ZnO is an important II-IV direct wide band gap semiconductor materials at room temperature, the band gap is 3.37 eV, the high exciton binding energy of 60 meV, is considered to be a promising UV light emitting material. At the same time it is also a kind of multi functional oxide materials, photoelectric, piezoelectric, ferroelectric, pyroelectric that has excellent properties of the magnetic field, can be widely used in transparent electrodes, piezoelectric materials, varistors, acoustic wave devices and solar cells and other areas.
At present, ZnO research mainly focuses on the study of ZnO doped ZnO films, and ZnO nano structure. In nano structure field, researchers have made great progress, but the application of nano ZnO devices still have a long way to go. As everyone knows, the performance of the material depends on the structure of the material, and the material structure and depends largely on in the preparation method and process. Therefore, the material morphology, controllable preparation of size, for the application of nano ZnO devices is essential prerequisite.
This paper adopts the simple water bath method, using zinc nitrate (Zn (NO_3) _2 6H_2O six (four), methylene amine (CH_2) 6N_4) and ethylenediamine (C2H8N2) as raw materials, flowerlike ZnO structure were prepared to study the growth process / principle, in different experimental conditions (concentration, temperature that time, the ratio of reactants) with different morphologies of ZnO micro nano materials were prepared to investigate the effects of factors on the morphology and structure, and the photoluminescence spectra and UV Vis absorption spectroscopy was used to characterize the optical properties. In addition, the ordinary glass sheet as the substrate, the a water bath was prepared flowerlike ZnO arrays and S doped flowerlike ZnO arrays, studied S doped flowerlike ZnO arrays of structure, morphology and luminescent properties of influence. By X- - ray diffraction (XRD) phase analysis, field emission scanning electron microscope (FESEM) transmission (TEM, with electron microscope Selective electron diffraction (SAED) was used to observe the morphology of the products. Photoluminescence (PL) spectra were measured at room temperature with fluorescence spectrometer (excitation lamp as Xe lamp), and ultraviolet visible light absorption spectrum of samples was analyzed by ultraviolet spectrometer.
(1) flowerlike ZnO petals six pyramid structure, XRD test showed that the wurtzite structure of ZnO, indicating that the crystal structure of high resolution transmission electron microscopy and electron diffraction patterns, and along the growth from the c axis, energy spectrum analysis showed that the Zn and O elements, which is close to 1:1 that indicated that the crystal is good.
(2) the concentration of reaction solution, growth temperature, growth time, effect of reactant ratio on the morphology greatly. With the increase of the concentration of reaction solution, micro nano flowerlike ZnO growth rate accelerated, increase in size, compact crystal, crystal quality improved. With decreasing growth temperature, nucleation agglomerate resulting in petals in addition, aggregation; the decrease of the temperature reduces the rate of reaction, and the grains are not fully developed. With the extension of the growth time, early helps grain development and grow up, but when the time is too long, easily lead to "dissolve" phenomenon, the decline in the quality of crystal. The selective adsorption of ethylenediamine provides two nucleation and growth point therefore, in the form of play a decisive role in the flower shaped ZnO structure, and six methylene four amine only affect petal morphology, adsorption inhibited their growth in petals side, the petals is more slender.
(3) there are two characteristic peaks in the PL spectrum of ZnO, which are 365 nm narrow ultraviolet emission peak and 406 nm wide ultraviolet violet photoluminescence peak. Different reaction conditions (concentration of reaction solution, growth temperature and reactant ratio) also affect the photoluminescence property.
(4) the uniformity and orientation of S doped micro nano flower ZnO array were higher than that of the ZnO array without micro nano flower, but the surface became rough. In addition, the S emission peak of PL spectra of products decreased and a strong green emission peak appeared.

【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TB383.1

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