Siliconized triarylamines as redox mediator in dye-sensitized solar cells.

A new class of triarylamine compound functionalized with bulky triisopropylsilyl ether (-OTIPS) groups is used as a hole transport material in dye-sensitized solar cells (DSSCs). Using both optical and photoelectrochemical techniques, we compared the performance of this compound with that of a parent compound containing methyl ethers as well as the conventional I₃⁻/I⁻ redox couple. DSSCs fabricated with the triisopropylsilyl ether-substituted triarylamine exhibited high open circuit potentials (V(oc) > 0.9 V on average) and efficiencies of up to 1.9%. However, cells fabricated with triarylamine containing methyl ethers performed very poorly, pointing to the importance of -OTIPS in the overall performance of this material.