Synthesis Of Organic Photosensitizer Based On Truxene And Their Photovoltaic Performance

As a kind of renewable energy, the solar energy is abundant and infinite. Recently, it has become the focus of public concern, owing to its advantages: large-area fabrication, low cost and simply design. Using organic dye as the sensitizer of dye-sensitized solar cell (DSSCs) not only was able to reduce environmental pollute but also alleviate the waste of resources. At the same time, DSSCs using the principle of the photoelectric conversion to make the full use of the solar energy. Therefore, it has good prospects.In this thesis, we have synthesized seven new dyes starting as indanone to get the intermediate after some reactions such as Vilsmeier, Suzuki, Witting-Horner, Stille, Knoevenagel. One new class of triarylamine organic dyes (MXD1-4) based on truxene that contain triarylamine as donor and cyanoacrylic acid as electron acceptor (anchoring groups), bridged by methine, thiophene, bithiophene or 3,4-ethylenedioxythiophene (EDOT); the other class of bis-hexapropyltruxeneamino-based organic dyes we designed, MXD1-7 contain bis-hexapropyltruxeneamino as electron donor and cyanoacrylic acid as electron acceptor (anchoring groups), bridged by thiophene and 3,4-ethylenedioxythiophene (EDOT). The structures of the new compounds have been characterized by IR nuclear, magnetic resonance and mass spectra (MS) techology. The photophysical, electrochemical properties and the performance on DSSCs of the three dyes (MXD1-7) are measured and studied.It was found that the compounds have strong absorption (400-550nm) in the visible spectrum and high molar extinction coefficient(40～75×10³M^-1cm^-1). In addition the HOMO-LUMO levels of MXD1-7 dyes are suitable for DSSCs. Apply the seven dyes (MXD1-7) to the DSSCs, we found that they all have high IPCE value and high power conversion efficiencies. Among the two class of dyes, the DSSCs based on the dye MXD4 and MXD7 showed the best photovoltaic performance: a short-circuit photocurrent density (J_SC) of 11.5 and 11.8 mA cm^-2, an open-circuit photovoltage (V_OC) of 772 mV, and a fill factor (ff) of 0.68, corresponding to an overall conversion efficiency of 6.04 % and 6.18 % under 100 mW cm^-2 irradiation, respectively.