Ni-NiO-Ni tunnel junctions for terahertz and infrared detection.
Ni-NiO-Ni tunnel junctions for terahertz and infrared detection.
复制标题
用于太赫兹和红外检测的 Ni-NiO-Ni 隧道结。
作者：
P. Hobbs;R. Laibowitz;F. Libsch
我们提出了完整的实验测定的隧道势垒参数（两个势垒高度、结面积、介电常数和非本征串联电阻）作为亚微米Ni-NiO-Ni薄膜隧道结的温度的函数，表明当温度不变参数被迫一致时，在I-V曲线和该极低势垒系统的Simmons方程之间获得了良好的拟合（测量的φ约为0.20 eV）。清楚地示出了由于上电极和下电极的不同处理历史而导致的势垒高度的大约10 meV的分裂，其中上界面具有较低的势垒，这与在更尖锐的材料界面处的图像电势的增加的效果一致。据信，这是第一个具有足够分辨率的势垒高度测量，可以看到这种效应。一种制造技术，产生高产率和一致的结的行为，以及在4 K的非弹性隧穿光谱的初步结果，显示在-59 meV的一个突出的峰值，稍微移动相对于预期的横向光学声子激发在体NiO，但与其他表面敏感的实验一致。我们讨论了这些结果的影响，为太赫兹和红外辐射的有效探测器的设计。
We present complete experimental determinations of the tunnel barrier parameters (two barrier heights, junction area, dielectric constant, and extrinsic series resistance) as a function of temperature for submicrometer Ni-NiO-Ni thin-film tunnel junctions, showing that when the temperature-invariant parameters are forced to be consistent, good-quality fits are obtained between I-V curves and the Simmons equation for this very-low-barrier system (measured phi approximately 0.20 eV). A splitting of approximately 10 meV in the barrier heights due to the different processing histories of the upper and lower electrodes is clearly shown, with the upper interface having a lower barrier, consistent with the increased effect of the image potential at a sharper material interface. It is believed that this is the first barrier height measurement with sufficient resolution for this effect to be seen. A fabrication technique that produces high yields and consistent junction behavior is presented as well as the preliminary results of inelastic tunneling spectroscopy at 4 K that show a prominent peak at -59 meV, shifted slightly with respect to the expected transverse optic phonon excitation in bulk NiO but consistent with other surface-sensitive experiments. We discuss the implications of these results for the design of efficient detectors for terahertz and IR radiation.