Developing photosensitizers with high extinction coefficients, proper electronic structures, and steric properties is warranted for the dye-sensitized solar cells (DSCs) employing one-electron outer-sphere redox shuttles. DSCs incorporating Co(II/III)tris(1,10-phenanthroline)based redox electrolyte and three synthesized organic dyes as photosensitizers (M14, M18, and M19) are described. The hexapropyltruxene group on the dyes retards the rate of interfacial back electron transfer from the conduction band of the nanocrystalline titanium dioxide film to the [Co(III)-(phenanthroline) 3 ] 3+ ions, which enables attainment of high photovoltages approaching 0.9 V. The measurement of photocurrent transients shows that the mass transport limitation of the cobalt redox shuttle has been largely removed by using thin TiO 2 films. DSCs sensitized with M14 in combination with the cobalt redox shuttle yield a DSC with an overall power conversion efficiency (PCE) of 7.2% under 100 mW cm −2 AM1.5 G illumination. The influences of the dye structure on the performance of DSCs were also investigated.

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New building blocks of cores and periphery groups for organic hole-transporting materials (HTMs) have been paid much attention for recent development in perovskite solar cells (PSCs). In this work, we applied facile synthesis to join a 2,4,6-triarylpyridine building block for new HTMs based on a pyridine core by cheap industrial initial materials. The three small molecules, namely, D104, D105, and D106, were used in the pristine state. To the best of our knowledge, pyridine-cored dopant-free HTMs have not been reported in PSCs. The changing periphery 4-methoxyphenyl and bis(4-methoxyphenyl)amine groups formed different Y-shapes. Under 1 sun conditions, the devices achieved an increased power conversion efficiency (PCE) of 16.28%, 17.40%, and 18.24% for D104, D105, and D106. They displayed great potential with improved stability in inverted planar PSCs. The unencapsulated device in ambient environment (30% RH) based on D104, D105, and D106 retained 33%, 70%, and 75% of the initial PCE after 275 h.

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