Fast time-resolved electrostatic force microscopy: Achieving sub-cycle time resolution
Fast time-resolved electrostatic force microscopy: Achieving sub-cycle time resolution
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DOI：
10.1063/1.4948396
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发表时间：
2016-06-01
影响因子：
1.6
通讯作者：
Ginger, David S.
中科院分区：
文献类型：
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作者：
Karatay, Durmus U.;Harrison, Jeffrey S.;Ginger, David S.
利用广泛可用的原子力显微镜硬件测量低于衍射极限的微秒和纳秒尺度局部动态的能力将使从生物学到半导体物理学等领域的新科学研究成为可能。然而，商业上可获得的扫描探针仪器通常提供仅在毫秒到秒的时间尺度上测量动态的能力。在这里，我们详细描述了快速时间分辨的静电力显微镜使用振荡悬臂作为一种手段来测量快速本地动态扰动后的样品的实施。我们展示了如何振荡悬臂相对于扰动事件的相位是至关重要的，以实现可靠的子周期时间分辨率。我们探讨了噪声如何影响可实现的时间分辨率，并提出了经验准则，以减少噪声和优化实验参数。具体来说，我们表明，减少噪声的悬臂梁上使用光热激励，而不是压电声激励进一步提高了时间分辨率。我们证明了歧视的信号上升时间与时间常数快至10 ns，并同时进行数据采集和分析，大大提高了图像采集时间。出版社：AIP Publishing
The ability to measure microsecond- and nanosecond-scale local dynamics below the diffraction limit with widely available atomic force microscopy hardware would enable new scientific studies in fields ranging from biology to semiconductor physics. However, commercially available scanning-probe instruments typically offer the ability to measure dynamics only on time scales of milliseconds to seconds. Here, we describe in detail the implementation of fast time-resolved electrostatic force microscopy using an oscillating cantilever as a means to measure fast local dynamics following a perturbation to a sample. We show how the phase of the oscillating cantilever relative to the perturbation event is critical to achieving reliable sub-cycle time resolution. We explore how noise affects the achievable time resolution and present empirical guidelines for reducing noise and optimizing experimental parameters. Specifically, we show that reducing the noise on the cantilever by using photothermal excitation instead of piezoacoustic excitation further improves time resolution. We demonstrate the discrimination of signal rise times with time constants as fast as 10 ns, and simultaneous data acquisition and analysis for dramatically improved image acquisition times. Published by AIP Publishing.