Abstract
To investigate the detailed photophysical properties of dye-sensitized solar cell (DSSC), we set up a complete system to measure and analysis the charge transfer and transport processes in DSSCs. The relationship between dye structure and the charge transfer kinetics can thus be clarified. We utilize the measurement systems to analyze DSSCs employed a series of Ru-based sensitizers and metal-free organic D-π-A dyes. In the first chapter, we briefly review the development of photovoltaics, including the state-of-the-arts DSSCs. The operation principles and characteristics of DSSCs are described in the first part of the second chapter followed by the details of carrier dynamics at each steps. The loss mechanisms are also investigated and correlated to the performance of solar cells. The measurement setups and principles (substrate/counter electrode side illumination external quantum efficiency analysis, SE/CE E.Q.E., transient photovoltage/photocurrent TPV/TPC, transient absorption spectrum, TAS) are also addressed in this chapter. The photophysical measurements are employed to analysis the Ruthenium-based and metal-free organic Donor-π conjugated-Acceptor (D-π-A) sensitizers in the third and fourth chapter, respectively. We analyze carrier behaviors of PRT series sensitizers and compared that with N749. Devices characteristics can be correlated to the charge transfer processes. Instructive results for future development of Ru-based sensitizers are acquired. Systematic results are also obtained in the DSSCs employed metal-free organic D-π-A sensitizers (DPTP, OHexDPTP, TPCADTS, and TP6CADTS). It is found that the photophysical properties of D-π-A sensitizer DSSCs are highly depended on the molecular structures of dyes (e.g. π-bridges and anchoring groups on donor chromophores).