Herein, I(V) characteristics of the tunnel junction between the scanning tunneling microscopy (STM) Pt/Ir probe and atomically flat Au film on mica using ultrahigh vacuum STM is investigated. To ensure cleanness and flatness of the Au films, optimization of the substrate annealing and Ar plasma treatment are performed. The obtained technological parameters allow to drastically improve the reproducibility of I(V) measurements. The analysis of I(V), d²I/dV² (V), and Fowler–Nordheim plots is conducted, and the presence of the features in the bias region near 1.8 V in the form of peak and minimum, peak and anomalous extra minimum, respectively is demonstrated. The direct optical measurements confirm that the features on I(V) curves are associated with the generation of photons from the STM probe‐sample gap, governed by inelastic tunneling processes. The proposed I(V) analysis approach is used for indirect sensing and investigation of the light emission in the tunnel junction offering a powerful tool for the studies of the photonic sources with deeply subwavelength dimensions.

中文翻译：

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间接检测本地隧道交界处的发光

本文中，使用超高真空STM研究了扫描隧道显微镜（STM）Pt / Ir探针与云母上原子平坦的Au膜之间的隧道结的I（V）特性。为了确保Au膜的清洁度和平坦度，对基板退火和Ar等离子处理进行了优化。所获得的技术参数可以极大地提高I（V）测量的可重复性。的分析我（V），d ²我/ d V ²（V），并进行了Fowler-Nordheim绘图，并证明了在1.8 V附近的偏置区域中分别以峰值和最小值，峰值和异常额外最小值的形式存在特征。直接光学测量结果证实，I（V）曲线上的特征与STM探针-样品间隙中光子的产生有关，并受非弹性隧穿过程的控制。提议的I（V）分析方法用于间接检测和研究隧道结中的光发射，为研究深亚波长尺寸的光子源提供了有力的工具。