We explore a disruptive approach to nanoscale sensing by performing electron energy loss spectroscopy through the use of low-energy ballistic electrons that propagate on a two-dimensional semiconductor. In analogy to free-space electron microscopy, we show that the presence of analyte molecules in the vicinity of the semiconductor produces substantial energy losses in the electrons, which can be resolved by energy-selective electron injection and detection through actively controlled potential gates. The infrared excitation spectra of the molecules are thereby gathered in this electronic device, enabling the identification of chemical species with high sensitivity. Our realistic theoretical calculations demonstrate the superiority of this technique for molecular sensing, capable of performing spectral identification at the zeptomol level within a microscopic all-electrical device.

我们通过使用在二维半导体上传播的低能弹道电子来执行电子能量损失光谱，探索纳米级传感的颠覆性方法。与自由空间电子显微镜类似，我们发现半导体附近分析物分子的存在会在电子中产生大量能量损失，这可以通过主动控制电势门进行能量选择性电子注入和检测来解决。因此，分子的红外激发光谱被收集在该电子设备中，从而能够高灵敏度地识别化学物质。我们的现实理论计算证明了这种分子传感技术的优越性，能够在微观全电装置内进行 zeptomol 水平的光谱识别。