Dye-sensitized solar cells using phthaloylchitosan based gel polymer electrolyte containing I¯/I3¯ redox species / Shahan Shah

• Main Author: Shahan , Shah
• Format: Thesis
• Published: 2016
• Subjects: Q Science (General)
• Online Access: http://studentsrepo.um.edu.my/9686/1/Shahan_Shah.pdf; http://studentsrepo.um.edu.my/9686/2/Shahan_Shah_%2D_Dissertation.pdf; http://studentsrepo.um.edu.my/9686/

Gel polymer electrolytes (GPE) consisting of phthaloylchitosan (PhCh), polyethylene oxide (PEO), dimethylformamide (DMF), ethylene carbonate (EC),tetrapropyl ammonium iodide (TPAI) and iodine (I2) have been prepared and characterized using electrochemical impedance spectroscopy (EIS). The highest conductivity of 11.1 mS cm-1 was obtained for 5.04 wt.% PhCh-1.26 wt.% PEO-31.51 wt.% DMF-37.81wt.% EC-22.68wt.% TPAI-1.7 wt. % I2 GPE. Dye-sensitized solar cell (DSSCs) have been fabricated by sandwiching GPE between FTO/TiO2-dye photoanode and platinum/FTO counter electrode. The photocurrent density-voltage (J-V) characteristics of the DSSCs have been measured under white light illumination of 100 W m-2 with active area of 0.20 cm2. The optimized GPE exhibits the efficiency of 7.1 % using N3 dye as sensitizer and 0.81 % with mixed natural dyes. The natural dyes used were anthocyanin (An) and chlorophyll (Chl) which have been extracted from black rice and fragrant screwpine (Pandanus amaryllifolius) leave, respectively using methanol as solvent. The anthocyanin and chlorophyll dyes were characterized using UV-Vis absorption spectroscopy. While the anthocyanin dye has a broader absorption peak at 541 nm, the chlorophyll dye has two prominent absorption peaks at 410 nm and 663 nm. The anthocyanin and chlorophyll dyes were deposited sequentially on the TiO2 electrode. The optimized GPE has been added with tert-butyl-pyridine (TBP) at different concentration as additives and have been tested in DSSC. With the addition of 8 wt. % of TBP, the conductivity of GPE decreased to 10.28 mS cm-1. However,the open circuit voltage, (Voc) and the efficiency of DSSC using 8 wt. % TBP increased to 0.73 V and 8.84 %, respectively.