Modifikation der spektralen Eigenschaften eines einzelnen Moleküls vor einer Oberfläche

Abstract

This work treats experiments with single molecules in two different configurations: First, the molecules are embedded in a microcrystal which is glued to the tip of an optical fibre and approaches a gold surface. In these experiments a distance-dependent lineshift as well as a broadening of the spectral lines of single molecules are observed. Both effects are attributed to mechanical influences on the molecules. In the second configuration, the dye molecules are embedded in nanocrystals which are situated on a cover glass. The latter can be moved in front of an electrically contacted probe using a scanner. Owing to the Stark effect, in this case a strongly position-dependent lineshift of a single molecule can be induced by applying a voltage to the probe. This shift is used to image the probe