Effect of Cu Doping in the Structural, Electrical, Optical, and Optoelectronic Properties of Sol-Gel ZnO Thin Films
Effect of Cu Doping in the Structural, Electrical, Optical, and Optoelectronic Properties of Sol-Gel ZnO Thin Films
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DOI：
10.1149/1.3079619
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发表时间：
2009-04
影响因子：
3.9
通讯作者：
T. Ghosh;M. Dutta;S. Mridha;D. Basak
中科院分区：
文献类型：
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作者：
T. Ghosh;M. Dutta;S. Mridha;D. Basak
研究了Cu掺杂（0.08-4%）对ZnO溶胶-凝胶薄膜结构、电学、光学和光电子性能的影响。x射线衍射研究表明，掺杂膜是具有随机取向的单相纤锌矿结构。c轴参数呈下降趋势，下降幅度达0.5%，随后又呈上升趋势。场发射扫描电镜显示晶粒结构。能量色散光谱和薄膜颜色证实了铜的掺杂。光学透射率测量表明，当Cu含量达到0.3%时，薄膜在可见光区域的透明度为80%。通过四个探针的电阻率和电流-电压测量表明，掺杂薄膜变得非常电阻。光致发光光谱显示，铜掺杂后，在515 nm处出现绿色发光，在376 nm处的紫外峰强度大幅降低。然而，当掺杂量增加到0.5%以上时，没有观察到绿色发光。结构、电学和光学性质的变化与间隙缺陷有关。光电导率研究表明，薄膜的紫外灵敏度提高了0.1%，可以作为紫外传感器使用。
The effect of Cu doping (0.08-4%) on the structural, electrical, optical, and optoelectronic properties of sol-gel ZnO thin films deposited on glass substrates have been investigated. X-ray diffraction studies show that the doped films are single-phase wurtzite structure with random orientations. A decreasing trend in the c-axis parameter up to 0.5% is observed followed by an increasing trend above that. Field-emission scanning electron microscopy shows a grain texture. The energy dispersive spectroscopy as well as the film color confirms the Cu doping. Optical transmittance measurements show 80% transparency in the visible region for the films up to 0.3% Cu content. The doped films become very resistive as indicated by the four probe electrical resistivity and current-voltage measurements. The photoluminescence spectra reveal with Cu doping, a green emission at 515 nm appeared and the UV peak intensity at 376 nm is drastically lowered. However, no green emission is observed as the doping is increased beyond 0.5%. The changes in the structural, electrical, and optical properties are correlated to interstitials defects. The photoconductivity studies show that the UV sensitivity of the films is enhanced up to 0.1%, which indicates that the films can be used as UV sensors.