APPLICATION OF PHOTOSYNTHETIC PIGMENTS FROM MARINE MICROALGAE NAVICULA SP. AS SOLAR CELLS SENSITIZER

• Main Author: (NIM: 20512007) ; Pembimbing Dr. Santi Nurbaiti , Zeily Nurachman, D.Sc, HAIRUNNISA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/18576
• Institution: Institut Teknologi Bandung

Solar cells sensitized by natural organic materials continue to be developed recently, which are more economical and more environmentally friendly than the synthetic sensitizers. The commonly used natural organic sensitizer are pigments from fruits and vegetables, but the utilization of these resources will compete againts the fulfillment of human food. Navicula sp., one of the marine microalgae, is potential as an alternative pigments source for solar cells sensitizer. The purposes of this research are to isolate and characterize the photosynthetic pigments from Navicula sp., then test the photoelectric ability of the solar cells sensitized by Navicula sp. pigments. This research was conducted through cultivation of Navicula sp. in a photobioreactor containing seawater enriched with nutrients from the modified medium (Urea, NaH2PO4.2H2O, FeCl3, Na2EDTA and Na2SiO3.5H2O); pigments isolation by extracting dried-biomass in acetone; pigments purification using column chromatography; pigment characterization by spectra absorption scanning in ultraviolet and visible light; fabrication of solar cells with 3 different TiO2 pastes, A, D and S; and test the photoelectric capability of the dye-sensitized solar cells. The results showed that the best cultivation of Navicula sp. in modified medium produced 6.52 g of biomass density. There were 7 pigments obtained from Navicula sp. which have characteristic of absorption spectra at 350 – 900 nm and identified having similarities with β-carotene (424, 449, 474 nm), pheophytin a (410, 665 nm), chlorophyll a (430, 662 nm), diatoxanthin (405, 429, 457 nm), diadinoxanthin (429, 449, 476 nm), fucoxanthin (422, 446, 470 nm) and chlorophyll c (441 nm). All of the solar cells sensitized by a mixture of fucoxanthin and chlorophyll a (1:1) produced photoelectric characteristics of Jsc 2.93×10-3 mA/cm2, Voc 0.375 V, FF 0.392 and ɳ 4.32×10-5% for solar cells with paste A; also Jsc 0.004 mA/cm2; Voc 0.01 V, FF 0.54 and ɳ 2.38×10-5% for solar cells with paste D. Meanwhile, The best photoelectric characteristic obtained from solar cells with paste S which produced Jsc 0.008 mA/cm2, Voc 0.130 V, FF 2.76 and ɳ 3.17×10-4%.