Vibrational Spectroscopy of Subnanogram Samples with Tunneling Spectroscopy

Abstract

As mentioned in Chapter 1, sample preparation is the most challenging part of tunneling spectroscopy. In sample preparation, the most critical step is doping the junction. Thus, it is understandable that a great deal of time and energy have gone into development of improved techniques for doping. The three general categories of techniques that have been discussed thus far in the book are (1) vapor doping, (2) liquid phase doping, and (3) infusion doping. In this chapter we discuss a relatively new technique for liquid phase doping in which a very small drop of dopant solution is placed on the tunneling barrier and evaporated to dryness. This simple new technique has the advantage that it requires orders of magnitude less of the doped compound than other techniques.