A feasible scalable porphyrin dye for dye-sensitized solar cells under one sun and dim light environments

We have devised a new porphyrin dye Y1A1 for photovoltaic applications under both light sources of AM1.5G standard conditions and low light intensity at 300-2400 lux. The dye Y1A1 is tailored with two 3,5-di-tert-butyl-4-methoxyphenyl groups at meso-10,20-positions which helps the solubility of the molecule in solvents and avoids involvement of the hazardous chemical n-butyllithium, which is used during the synthesis of some typical high efficiency porphyrins such as YD2-o-C8 and LD-series dyes. The dye is also structurally simple so that large-scale synthesis for future industrial applications becomes feasible. The Y1A1-based cells were found to exhibit higher performance using I-/I-3(-) rather than Co2+/(3+) electrolytes in the presence of CDCA co-adsorbent. The addition of Li+ additive to the GuSCN-free electrolyte benefits the performance in terms of higher capacitance at the compensation of surface charge recombination and electron lifetime. The optimized cells based on Y1A1 showed a power conversion efficiency of 9.22% under AM1.5G conditions and as high as 19.5% when illuminated under 350 lux of LED light.