Charging of 2D Au nanoplatelets deposited on an insulating SiO2 substrate to or from the tip of a non-contact atomic force microscope (nc-AFM) is demonstrated. Charge transfer is controlled by monitoring the resonance frequency shift Δf(V) during the bias voltage ramp V applied to the tip-back electrode junction. The onset of charge transfer is revealed by a transition from a capacitive parabolic behavior to a constant Δf(V) region for both polarities. An analytical model, based on charging by electron field emission, shows that the field-emitted current saturates shortly after the onset of the charging, due to the limiting effect of the charge-induced rise of the Au platelet potential. The value of this current plateau depends only on the rate of the bias voltage ramp and on the value of the platelet/SiO2/back electrode capacitance. This analysis is confirmed by numerical simulations based on a virtual nc-AFM model that faithfully matches the experimental data. Our charging protocol could be used to tune...

中文翻译：

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通过场发射 nc-AFM 控制绝缘体上金纳米片的电荷

演示了沉积在绝缘 SiO2 衬底上的二维 Au 纳米片与非接触式原子力显微镜 (nc-AFM) 的尖端之间的充电。电荷转移是通过在施加到尖端-背面电极结的偏置电压斜坡 V 期间监测谐振频移 Δf(V) 来控制的。电荷转移的开始通过从电容抛物线行为到两个极性的恒定 Δf(V) 区域的转变来揭示。基于电子场发射充电的分析模型表明，由于电荷诱导的 Au 片电势升高的限制效应，场发射电流在充电开始后不久就饱和。该电流平台的值仅取决于偏置电压斜坡的速率和薄片/SiO2/背电极电容的值。该分析通过基于真实匹配实验数据的虚拟 nc-AFM 模型的数值模拟得到证实。我们的充电协议可用于调整...