Seaweed chlorophyll on the light-electron efficiency of DSSC

Four different seaweed extracts were employed as the dyes of dye sensitized solar cells (DSSCs) to investigate the light-electron efficiency. The sensitizers, extracted from Nannochloropsis spp., Tetraselmis spp., Gracilaria spp., and Ulvales spp., showed their light-electronic transfer ability in different light intensities. Among them, Ulvales output a higher light-voltage, about 0.4 V. The output voltage increased when light intensity increased. Gracilaria extract produced a higher output voltage at 35 Lux, but its output voltage decreased over 500 Lux. The sensitizers extracted from these seaweeds had monochromatic incident photon-to-electron conversion efficiencies (IPCE) between 23-61% in 220-260 nm wavelengths. Among them, Ulvales output higher IPCE than Tetraselmis and Nannochloropsis. SEM analysis of DSSC surfaces revealed that the efficiency of seaweed DSSCs was governed by chlorophyll size. The chlorophyll particle size of Ulvales spp. was the largest. The chlorophyll particle size of Gracilaria spp. was the smallest and yielded the lowest IPCE.