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Bi催化生长、掺杂和修饰ZnO纳米线的制备及光学性质研究
Synthesis and Optics Property of Bi Catalyzed、 Doped and Modified ZnO Nanowires
【作者】 周阳；
【导师】 高义华；
【作者基本信息】 华中科技大学 ， 物理电子学， 2011， 硕士
【摘要】 ZnO是一种直接带隙的半导体发光材料,室温下禁带宽度为3.37 eV,激子束缚能为60meV。金属元素Bi具有非常丰富的电子壳层结构,能有效地调节ZnO纳米结构的表面状态,进而达到调控其性能及应用的目的。本文主要结果如下:(1)以BiI3粉、Zn粉为原料,在Si衬底上,利用CVD的方法,在较低温度下成功制备了各种形貌的ZnO纳米线。通过研究温度、气压等因素对纳米线生长的影响,分析得出了Bi催化ZnO纳米线生长的基本规律。并通过PL谱的测试发现了材料能带变化的特征。(2)以Bi粉和Zn粉作为原料,在镀金的Si衬底上,利用CVD的方法,获得了Bi掺杂的ZnO纳米线。利用XPS的方法分析检测出了ZnO:Bi中Bi的含量为0.653%。通过荧光光谱研究,发现光谱出现了一定程度的红移,在704nm处发现,定性解释了新的较强发光峰值的出现。(3)用化学气相法在ITO玻璃上制备了ZnO线,通过水热法对ZnO纳米线进行了Bi修饰。对修饰结果进行了详细表征和分析,证实了单晶Bi对ZnO纳米线的修饰。并对修饰后的纳米线进行了光吸收谱的测定,利用Tauc方程比较了修饰前后纳米线的能带结构,解释了光吸收谱红移现象发生的原因。
【Abstract】 Znic oxide is a semiconductorr with a direct wide band gap of 3.37 eV at room temperature, its exciton has a binding energy up to 60 meV. The properties of ZnO nanowires can be adjusted by the metal element Bi doping techniques,which is rich in the electronic shell structure.It can effectively adjust the surface state of ZnO nano-structures in order to make some new the properties and applications. The main results of my research including the following aspects:(1) Using vapor transport method and Zn、BiI3 powder as source material, we successfully synthesized ZnO nanowires with different morphologies. The influences of temperature, vacuum pressure, O2 pressure on the ZnO nanowires’growth were studied. And we found out the basic rules of Bi catalyzing ZnO nanowires and the characteristics of energy band by PL.(2) Using vapor transport method and Zn, Bi powder as source material, we synthesized Bi doped ZnO nanowires on silicon substrate with gold films and also detected the Bi content is 0.653% in ZnO:Bi nanowires through the XPS analysis. We analyzed photoluminescence (PL) spectrum of the ZnO: Bi nanowires. We found and discussed that the PL spectrum peak has a red shift when the Bi-doped ZnO nanowires.(3) Using vapor transport method, we synthesized Bi surface-modified ZnO nanowires on ITO substrate.This result is confirmed through a series of experimental results and synthesizations. We compared the result with pure ZnO nanowires by employing Optical absorption and find out the influence of the modified layer’s thickness to the Optical absorption. Moreover, we compared the nano energy structure by Tauc equation and presented the red shift of the possible reasons.