氧化锌薄膜与纳米棒的制备及其性质研究

发布时间：2018-01-21 02:52

  本文关键词： ZnO 水热法 CVD 阵列 薄膜 掺杂 形貌　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：ZnO是一种宽禁带(室温下为3.37 eV)直接带隙半导体材料,其波长处于近紫外范围,对可见光是透明的,氧化锌的激子束缚能约为60 meV。氧化锌能够在比较低的温度下制备,可以用不同的基底来生长,既能用单晶衬底(如蓝宝石、Si等)来制备,又能用非晶衬底(如玻璃、塑料等)来制备。除过体单晶和薄膜,氧化锌的纳米构成非常丰富,因为纳米结构有比表面积大的特点,所以适用于传感器领域。此外,氧化锌的工艺简单、热稳定性高、体单晶易得等优点。因此,ZnO是新一代的光电半导体材料,目前半导体材料与器件研究皆聚焦于此。本论文运用水热法、化学气相沉积(CVD)法分别制备了氧化锌纳米阵列和薄膜,涂层对ZnO进行Al掺杂、Ag/N双掺杂,并制备异质pn结。研讨、剖析了氧化锌纳米阵列和薄膜的制备工艺、生长机理及一些相干特性,大部分研究工作和结果如下:1、应用浸渍提拉法在玻璃基片上涂覆ZnO晶种膜层,对晶种生成质量的影响因素如Zn2+浓度、Zn源溶剂、涂覆次数、退火温度进行了较为细致的研究分析,并以此为依据优化了二步法的晶种制备工艺。实验发现采用0.01M的乙酸锌乙醇溶液涂覆8到10次并在500℃下退火处理2h可以获得质量较好的ZnO晶种膜层。2、以上述晶种层作为生长基点,在不同浓度的生长溶液内尝试了ZnO纳米棒的恒温水浴生长,并在不同条件下进行CVD法制备ZnO薄膜,对ZnO阵列和薄膜的SEM图片做了初步探讨与分析。研究发现,以载玻片作衬底,水热法采用0.05M的生长溶液在95℃下恒温水浴生长4h到5h均可获得取向良好、分布密实、直径大小均匀的ZnO纳米棒及其一维阵列。CVD法采用0.005M晶种溶液,三温区管式炉的温度为800℃-450℃-450℃生长1h,充入O2流量35sccm、Ar2流量10sccm时可获得颗粒尺寸均匀的ZnO纳米薄膜。3、涂层制备ZnO纳米薄膜,向其中掺杂Al、(Ag,N),在n-Si和p-Si上制备薄膜形成异质pn结,并测量它们的电阻值和I-V曲线。对电阻值进行测量,n型掺杂的材料导电性比未掺杂的材料有了明显的改善;对pn结进行电学性能测量,ZnO异质pn结出现了典型的整流曲线,相比而言,p-Si/ZnO:(Al)结比ZnO:(Ag,N)/n-Si结具有较好的电学性能;我们测定600℃退火温度下的pn结的整流曲线,比未退火的pn结有较好的电学性能,而最适宜的退火温度还需要我们进一步探究。
[Abstract]:ZnO is a wide bandgap semiconductor (3.37eV at room temperature). Its wavelength is near ultraviolet, and it is transparent to visible light. The exciton binding energy of zinc oxide is about 60 MEV. Zinc oxide can be prepared at relatively low temperature and can be grown on different substrates, such as single crystal substrates (such as sapphire Si). Besides bulk single crystals and thin films, ZnO nanostructures are very rich because of their large specific surface area. In addition, zinc oxide has the advantages of simple process, high thermal stability and easy to obtain bulk single crystals. Therefore, ZnO is a new generation of optoelectronic semiconductor materials. In this thesis, ZnO nanoarrays and thin films were prepared by hydrothermal method and chemical vapor deposition (CVD) method, respectively. The coatings were used to doped ZnO with Al. The preparation process, growth mechanism and some coherent properties of ZnO nanoarrays and thin films are analyzed. Most of the research work and results are as follows: 1. The ZnO seed coating was coated on the glass substrate by impregnation Czochralski method. The factors affecting the seed formation quality such as Zn2 concentration Zn source solvent and the coating times were discussed. The annealing temperature was studied and analyzed in detail. On the basis of the above, the preparation process of the crystal seed by two-step method was optimized. It was found that the better quality Zn could be obtained by coating with 0.01m zinc acetate ethanol solution for 8 to 10 times and annealing at 500 鈩，

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