Fabrication and Characterization of CNT-Based Smart Tips for Synchrotron Assisted STM

Figure 6

(a) Normalized photocurrent map of the bare Pt₉₀Ir₁₀ tip (0.5 mm in diameter). The photocurrent is normalized with respect to the maximum current detected in the same plot; (b) normalized photocurrent map of a CNT-based smart tip (0.25 mm Pt₉₀Ir₁₀ wire coated with 350 nm SiO₂, attached to a CNT, as shown in the insert). A thick boron nitrite film is applied to the tip holder to additionally reduce the photocurrent. The black dash line is used as a guide to show where the tip apex is. The result shows that photocurrent is generated by the whole bare tip apex while the photocurrent of the smart tip is drastically reduced after coating the tip with SiO₂.

(a)

(b)