Department of Chemistry and Biochemistry, Queens College, Flushing, New York 11367, United States.
The Graduate Center of CUNY, New York, New York 10016, United States.
Anal Chem. 2022 May 24;94(20):7169-7173. doi: 10.1021/acs.analchem.2c00753. Epub 2022 May 9.
The use of scanning electrochemical microscopy (SECM) for nanoscale imaging of photoelectrochemical processes at semiconductor surfaces has recently been demonstrated. To illuminate a microscopic portion of the substrate surface facing the SECM probe, a glass-sealed, polished tip simultaneously served as a nanoelectrode and a light guide. One issue affecting nanoscale photo-SECM experiments is mechanical interactions of the rigid optical fiber with the tip motion controlled by the piezo-positioner. Here we report an improved experimental setup in which the tip is mechanically decoupled from the fiber and light is delivered to the back of the tip capillary using a complex lens system. The advantages of this approach are evident from the improved quality of the approach curves and photo-SECM images. The light intensity delivered from the optical fiber to the tip is not changed significantly by their decoupling.
扫描电化学显微镜（SECM）最近已被用于在半导体表面上对光电化学过程进行纳米级成像。为了照亮面向 SECM 探头的衬底表面的微观部分，一个玻璃密封的抛光尖端同时充当纳米电极和光导。影响纳米光电 SECM 实验的一个问题是光纤与由压电定位器控制的尖端运动之间的机械相互作用。在这里，我们报告了一种改进的实验装置，其中尖端与光纤在机械上解耦，并使用复杂的透镜系统将光输送到尖端毛细管的背面。从改进的接近曲线和光电 SECM 图像的质量可以明显看出这种方法的优势。光纤到尖端的光强度通过它们的解耦不会发生显著变化。
