| 초록 |
In both academia and industry, tremendous effort has been devoted to improving the power conversion efficiency of dye-sensitized solar cells (DSCs) to exploit their high efficiency, and low production costs. The efficiency of a DSC is determined by the short circuit current density (JSC), the open circuit voltage (VOC), and the fill factor (FF). These key parameters are strongly governed by the characteristics of the TiO2/dye/electrolyte interface, at which many electrochemical reactions occur. Modifications of the interfacial properties can alter the conduction band edge and shield the trap states of TiO2, thereby influencing VOC, JSC, and the recombination reaction of the photoinduced electrons with any oxidized species. In addition, interfacial recombination pathways act as a loss mechanism in competition with the transport processes. The photoinjected electrons in the TiO2 have two possible recombination pathways: Direct recombination with cations of the dye, or with the HTM. In this talk, I will present some modifications of heterogeneous interface using coadsorbents, organic dyes and electrolytes, influencing the energy gap (VOC) between the potential of the redox couple and the Fermi level, and discuss charge transportation phenomena in DSCs studied using nanosecond transient absorption spectrophotometer (TAS) and electrochemical impedance spectrophotometer (EIS). |
