Pulsed Force Kelvin Probe Force Microscopy
Pulsed Force Kelvin Probe Force Microscopy
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DOI：
10.1021/acsnano.0c00767
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发表时间：
2020-04-28
期刊：
影响因子：
17.1
通讯作者：
Xu, Xiaoji G.
中科院分区：
文献类型：
--
作者：
Jakob, Devon S.;Wang, Haomin;Xu, Xiaoji G.
测量材料的接触电位差和功函数对于分析材料的电子结构和表面残余电荷具有重要意义。Kelvin探针力显微镜（KPFM）是原子力显微镜的一种成像技术，已被广泛用于纳米尺度的表面势和功函数映射。然而，传统的KPFM变体在环境条件下的空间分辨率通常限于30-100 nm。光活性材料和半导体器件尺寸的不断减小和复杂性的不断增加，将对通过KPFM揭示其纳米级电学性质提出未来的挑战。在这里，我们介绍了一种基于原子力显微镜的脉冲力模式的KPFM技术。我们的技术，命名为脉冲力开尔文探针力显微镜（PF-KPFM），是一种单程技术，利用AFM针尖和导电样品之间的本征费米能级对准，而不需要外部振荡电压。诱导悬臂梁振荡产生的尖端和样品之间的电子的自发重新分配提取和用于获得悬臂梁振荡幅度，并推导出表面电位。PF-KPFM的空间分辨率被证明是
Measurement of the contact potential difference (CPD) and work functions of materials are important in analyzing their electronic structures and surface residual charges. Kelvin probe force microscopy (KPFM), an imaging technique of atomic force microscopy, has been widely used for surface potential and work function mapping at the nanoscale. However, the conventional KPFM variants are often limited in their spatial resolution to 30-100 nm under ambient conditions. The continuingly decreasing size and increasing complexity of photoactive materials and semiconductor devices will present future challenges in uncovering their nanometer-scale electrical properties through KPFM. Here, we introduce a KPFM technique based on the pulsed force mode of atomic force microscopy. Our technique, named pulsed force Kelvin Probe Force Microscopy (PF-KPFM), is a single-pass technique that utilizes the intrinsic Fermi level alignment between the AFM tip and the conductive sample without the need for an external oscillating voltage. Induced cantilever oscillations generated by a spontaneous redistribution of electrons between tip and sample are extracted and used to obtain the cantilever oscillation amplitude and to derive the surface potential. The spatial resolution of PF-KPFM is shown to be