Chen-Fu Lo

A strategy to design highly efficient porphyrin sensitizers for dye-sensitized solar cells

We designed highly efficient porphyrin sensitizers with two phenyl groups at meso-positions of the macrocycle bearing two ortho-substituted long alkoxyl chains for dye-sensitized solar cells; the ortho-substituted devices exhibit significantly enhanced photovoltaic performances with the best porphyrin, LD14, showing J(SC) = 19.167 mA cm(-2), V(OC) = 0.736 V, FF = 0.711, and overall power conversion efficiency η = 10.17%.

Effects of potential shift and efficiency of charge collection on nanotube-based porphyrin-sensitized solar cells with conjugated links of varied length

For dye-sensitized solar-cell devices fabricated from porphyrin sensitizers with links of varied length (PE1-PE4) adsorbed on anodic titanium-oxide nanotube arrays, we measured induced photocurrent and photovoltage decays under constant bias illumination; the evaluated efficiencies of charge collection of the devices show a systematic trend PE4 > PE3 > PE2 > PE1 at a large short-circuit current, implying that a long link would improve the charge separation if the electrons were effectively injected into the semiconductor.

Electrochemistry and spectroelectrochemistry of carboxyphenylethynyl porphyrins

Zinc 5-(4-carboxy-phenylethynyl)-10,20-biphenylporphines bearing various substituents on the 10,20-phenyl rings are studied for their electrochemical and spectroelectrochemical properties. Cyclic voltammetry and optically transparent thin-layer electrochemical measurements suggest that the first reductions of these porphyrins should be the reduction reaction of the carboxylic protons. For the porphyrin ring reactions, our study shows that the redox properties can be significantly affected by the alkoxyl chains on the 10,20-phenyl rings.