| Semiconductor nanocrystals exhibit strong quantum confinement effects, with the band gap shifting to higher energy with decreasing nanocrystal size. Optical spectroscopies have been used extensively to study the electronic and vibrational properties of nanocrystals. However, electronic spectroscopies have traditionally not been used to study nanocrystals because of difficulties in the preparation of samples to which electrical contact has been made. Because of advances in synthetic techniques, it is now possible to make electrical contact to nanocrystals in a variety of sample geometries, allowing for their study with electronic spectroscopy.; This thesis describes the development and application of techniques for studying nanocrystals using electron spectroscopy. In addition to a description of synthetic techniques, three areas of study are presented. First, a powerful and versatile technique for studying the surface of nanocrystals using photoelectron spectroscopy is described and applied to CdSe and InP nanocrystals. The surface of a nanocrystal directly affects its optical and electrical properties, but few direct studies have been made. Second, near edge x-ray absorption spectroscopy is presented as a technique of directly measuring the conduction band density of states in the nanocrystals. The results of this experiment on CdSe nanocrystals confirm the importance of the surface in determining electronic properties. Finally, direct electrical measurements across nanocrystals are presented. Electrical spectroscopies have the potential to measure not only the electronic structure of nanocrystals, but also the density of states of lower energy mode in these systems, including acoustic modes. |
