Au电极厚度对MgZnO紫外探测器性能的影响

利用分子束外延设备(MBE)制备了MgZnO薄膜.X射线衍射谱、紫外-可见透射光谱和X射线能谱表明薄膜具有单一六角相结构,吸收边为340 nm,Zn/Mg组分比为62:38.采用掩膜方法使用离子溅射设备,在MgZnO薄膜上制备了Au电极,并实现了Au-MgZnO-Au结构的紫外探测器.通过改变溅射时间,得到具有不同Au电极厚度的MgZnO紫外探测器.研究结果表明:随着Au电极厚度的增加,导电性先缓慢增加,再迅速增加,最后缓慢增加并趋于饱和;而Au电极的透光率则随厚度的增加呈线性下降.此外,随着Au电极厚度的增加,器件光响应度先逐渐增大,在Au电极厚度为28 nm时达到峰值,之后逐渐减小.

Effect of Au Electrode Thickness on The Performance of MgZnO UV Detector

MgZnO films were prepared by RF MBE equipment. X-ray diffraction, UV-visible transmission spectroscopy and X-ray energy dispersive spectroscopy indicated that MgZnO films had a single hexagonal phase structure with a shap absorption edge at ~340 nm, and the composition ratio of Zn and Mg was 62:38. Au electrodes were deposited on MgZnO thin films by an ion sputtering apparatus with a mask and Au-MgZnO-Au UV detectors were fabricated. Au electrodes thicknesses could be modified by changing the sputtering time. With the increasing of Au electrode thickness, the conductivity of Au films increased slowly at first, then increased rapidly, and slowly to saturation finally. As for the transmittance of Au films, it decreased nearly linearly with the increasing of Au electrode thickness. In addition, with the increasing of Au electrodes thickness, the responsivity of MgZnO UV photodetectors gradually increased at first, and then decreased. When the thickness of Au electrode was 28 nm, the device has the best responsivity.