I. New Molecular Design & Synthesis of Organic Dye sensitizers
for Highly Efficient and Stable Dye-sensitized Solar Cells
Dye Sensitizers play a major role in the performance of the dye-sensitized solar cells based on nanocrystalline TiO2. The ideal sensitizer for dye-sensitized solar cells should absorb all light below a threshold wavelength of about 920 nm. In addition, it should be firmly grafted to the semiconductor oxide surface and inject electrons to the conduction band with a quantum yield of unity. The HOMO of the
dye should lie below the energy level of the redox mediator to allow efficient regeneration of the oxidized dye. Finally, it should be stable enough to sustain at least 108 redox turnovers under illumination corresponding to about 20 years of exposure to natural light. We have been involved in the synthesis and design of novel conceptual organic dye sensitizers, through molecular engineering with aim to 1) cosensitization of several dyes with different spectral response for panchromatic high efficiency dye-sensitized solar cells; 2) to long-term stable dye by introduction new anchoring group 3) to optimize and maximize their opto-physical properties; 4) to systematically establish the basic principles of the structural features and their topological requirements through photophysical and electrochemical properties analysis.
