| The research in this thesis has been aimed at defining the capabilities of Coherent Multidimensional Spectroscopy (CMDS) to guide and inform the synthesis and development of quantum confined semiconductors for new solar cell technology. The first triply electronically enhanced four wave mixing (TREE-FWM) CMDS of PbSe quantum dots is presented. The spectra contain useful information regarding the excitonic structure and coupling. The picosecond experiments provide a foundation for further development and extension of the technique to a femtosecond pulse system. The dynamics and charge transfer of interest within and between these materials are largely invisible to the picosecond experiment due to the subpicosecond dephasing of the excited superposition states. Over the course of this work, much was learned about the technicalities of performing CMDS on nanomaterials. Issues of concentration, sample handling, damage threshold, scatter, and stability played significant roles in the interpretation of the data. We conclude that the picosecond CMDS serves as a useful guide for the more versatile femtosecond CMDS under development. Future experiments will have the ability to map out the coherent dynamics important in the charge transfer and separation so integral to successful solar cell design. |
