铬掺杂氧化锌薄膜的超声喷雾法制备及其光学与磁学性质

发布时间：2018-06-22 09:43

  本文选题：超声喷雾法 + Cr掺杂ZnO薄膜　； 参考：《光谱学与光谱分析》2016年05期

【摘要】：用注射超声喷雾法将前驱体由针管直接送入超声喷头内,在石英基板上制备Zn_(1-x)Cr_xO(x=0.0,0.01,0.03,0.05)薄膜。采用X射线衍射仪、扫描电子显微镜、荧光光谱仪、紫外-可见分光光度计、振动样品磁强计(VSM)等对薄膜的结构、光学和磁学性质进行测量。实验结果表明,未掺杂的ZnO薄膜为六角纤锌矿结构,沿着c轴(002)择优取向,而Cr掺杂抑制了薄膜的c轴择优取向性;掺杂后的薄膜平均晶粒尺寸均增大,且当x=3%时,晶粒尺寸最大,达31.4nm。扫描电镜(SEM)下薄膜呈球形颗粒状,并且在x=5%下,薄膜出现了长条状的微观形貌。Cr掺杂使样品的光致发光谱(PL)发生了很大的变化:未掺杂的样品的PL谱在378nm处存在一个紫外发射峰,对应于550nm附近还存在一个由于缺陷态引起的绿光发射峰;掺Cr样品只有在350~550nm的很宽的范围内存在一个发射峰,对其进行高斯拟合后,发现掺Cr量为x=1%,3%,5%下样品均存在V_(Zn)(锌空位)、Zn_i(Zn间隙位)、V_(Zn)~-(带一个电子的锌空位)内部缺陷态,且当x=3%时,V_(Zn)最多。Cr的掺杂使得薄膜的带隙增大,并且x=3%时,禁带宽度最大,达到3.374eV。掺Cr的三个样品均具有室温铁磁性,且x=3%样品的磁化强度最大,其与V_(Zn)(锌空位)最大相对应,验证了Cr~(3+)和V_(Zn)的缺陷复合体是ZnO∶Cr样品具有稳定的铁磁有序的最有利条件的理论预测。
[Abstract]:Zn _ (1-x) Cr _ XO (x _ (0.01) Cr _ (1-x) Cr _ (1-x) Cr _ XO (x _ (0.01) C _ (0.01) O) thin films were deposited on quartz substrate by injecting ultrasonic spray method into the ultrasonic nozzle directly from the needle tube. The structure, optical and magnetic properties of the films were measured by X-ray diffractometer, scanning electron microscope, fluorescence spectrometer, UV-Vis spectrophotometer and vibrating sample magnetometer (VSM). The experimental results show that the undoped ZnO thin films are hexagonal wurtzite with preferred orientation along the c-axis (002), while Cr doping inhibits the c-axis orientation, and the average grain size of the doped ZnO films increases, and the average grain size increases when x = 3. The maximum grain size is 31.4 nm. Under scanning electron microscope (SEM), the film was spherical and granular, and at 5% XN, The photoluminescence spectra (PL) of the films changed greatly due to the appearance of long stripe morphology. Cr doping: the PL spectra of the undoped samples have a UV emission peak at 378nm. There is a green emission peak due to the defect state in the vicinity of 550nm, and there is only one emission peak for Cr doped samples in a very wide range of 350~550nm, which is fitted by Gao Si. It is found that there is a defect state in VZn (Zn gap) VZn (Zn gap)-(Zn vacancy with one electron) in the samples with 5% Cr doping, and the band gap increases when x = 3, and the band gap reaches 3.374eV when x = 3. The three Cr doped samples are ferromagnetic at room temperature, and the magnetization of XN 3% sample is the largest, which corresponds to the maximum V _ (Zn) (zinc vacancy). The defect complexes of Cr ~ (3) and V _ (Zn) were proved to be the most favorable conditions for the stable ferromagnetic ordering of ZnO: Cr samples.
【作者单位】： 福建师范大学物理与能源学院福建省量子调控与新能源材料重点实验室;福建省半导体光电材料及其高效转换器件协同创新中心;
【基金】：国家重点基础研究发展计划(973)项目(2011CBA00200) 国家自然科学基金项目(61574037,11004039) 福建省重大专项项目(2013HZ0003) 教育厅B类项目(JB14028)资助
【分类号】：O484.4
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