Effect of thermal annealing on the structural, electrical and optical properties of Al-Ni co-doped ZnO thin films prepared using a sol-gel method
Effect of thermal annealing on the structural, electrical and optical properties of Al-Ni co-doped ZnO thin films prepared using a sol-gel method
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DOI：
10.1016/j.surfcoat.2014.11.043
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发表时间：
2015-01
影响因子：
5.4
通讯作者：
Xianlei Zhang;K. S. Hui;Feng Bin;K. Hui;Lei Li;Y. Cho;R. Mane;Wei Zhou
中科院分区：
文献类型：
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作者：
Xianlei Zhang;K. S. Hui;Feng Bin;K. Hui;Lei Li;Y. Cho;R. Mane;Wei Zhou
采用溶胶-凝胶法在玻璃衬底上制备了Al-Ni共掺杂ZnO（NiAl：ZnO）薄膜。基于先前的研究，Zn 1 − xAlxO（AZO; Al/Zn = 1.5 mol%）薄膜优化为Ni含量为0.5 mol%，在N2/H2（95/5）形成气体中在450至600 °C的不同温度下退火1 h。研究了退火温度对薄膜结构、电学和光学性能的影响。X射线衍射分析表明，在500 °C退火的NiAl：ZnO薄膜结晶质量最好。XPS分析表明，NiAl：ZnO薄膜中存在金属Ni和Ni 2 O3态，Ni和Al原子成功掺杂，但未改变ZnO的晶体结构和取向。扫描电子显微镜（SEM）观察表明，薄膜表面平整致密，晶粒尺寸随退火温度的升高而增大，从23.8 nm增大到34.6 nm。根据霍尔效应测量，当温度达到500 °C时，薄膜的电阻率显示出1.05 × 10− 3（Ω cm）的最低值，这是NiAl：ZnO薄膜报道的最低电阻率。UV-Vis透射光谱表明，薄膜在可见光区的透过率大于80%，带隙由3.30 eV增加到3.55 eV。研究表明，在形成气体中的退火温度是影响薄膜质量的重要因素。此外，500 °C是NiAl：ZnO薄膜的最佳退火温度。本研究为制备高质量、高透明、低电阻率的光电用NiAl：ZnO薄膜提供了一种简单有效的方法。
Al–Ni co-doped ZnO (NiAl:ZnO) thin films were deposited on glass substrates using a sol–gel method. Based on a previous study, Zn1 − xAlxO (AZO; Al/Zn = 1.5 mol%) thin films optimized with a Ni content of 0.5 mol% were annealed at different temperatures from 450 to 600 °C in N2/H2(95/5) forming gas for 1 h. The effects of the annealing temperature on the structural, electrical and optical properties were determined. X-ray diffraction showed that NiAl:ZnO thin film annealed at 500 °C exhibited the best crystallization quality. XPS revealed the presence of metallic Ni and Ni2O3states, as well as Ni and Al atoms were successfully doped in NiAl:ZnO films, which did not result in a change in ZnO crystal structure and orientation. Scanning electron microscopy showed that the films were smooth and compact, and the grain size increased with increasing annealing temperature from ~ 23.8 nm to ~ 34.6 nm. According to the Hall Effect measurements, when the temperature reached 500 °C, the resistivity of the thin film showed the lowest value of 1.05 × 10− 3(Ω cm), which is the lowest resistivity reported for NiAl:ZnO films. The UV–Vis transmission spectra showed a high transmittance of more than 80% in the visible light range, and the band gap of the films was increased from 3.30 to 3.55 eV. This study showed that the annealing temperature in the forming gas is a vital factor affecting the quality of thin films. In addition, 500 °C was found to be the most appropriate annealing temperature for NiAl:ZnO films. This study provides a simple and efficient method for preparing high quality, high transparency and low resistivity NiAl:ZnO films for optoelectronic applications.