COMPUTATIONAL STUDY OF NATURAL DYE POTENCY AS ACTIVE MATERIAL IN DYE SENSITIZED SOLAR CELL

• Main Author: Fonda Maahury, Mirella
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/34093
• Institution: Institut Teknologi Bandung

Computational calculations have been done for natural dyes: curcumin, its derivatives and anthocyanin compounds. Computational calculations were performed to determine the stable structures and electronic properties of curcumin and anthocyanin which have potency as active material in the dye sensitized solar cells. The calculations were done using Density Functional Theory (DFT) for geometry optimization of the ground state and Time-Dependent Density Functional Theory (TDDFT) for single point calculation excited states. All calculations use functional B3LYP / 6-31G (d). The calculations were performed for the gas phase and solution phase. Geometry optimization calculations show that the structure of curcumin and its derivatives are more stable in the keto-enol structures compared to the diketo structures. The stable structures for anthocyanin are in the forms of cation structures. Curcumin, its derivatives (keto-enol) and anthocyanin compounds have small excitation energis. Most curcumin and anthocyanin compounds have high percentage excitation compositions HOMO to LUMO in solution phase. The density of HOMO-LUMO displays of curcumin and its derivatives in keto-enol structure are overlap with different densitis, whereas all the anthocyanin compounds only have been on its anthocyanidin. The absorption wavelength of curcumin and its derivatives (keto-enol) quite consistent with experimental data which is between its data for gas and solution phase while the calculated wavelength of anthocyanin compounds are shorter than experimental results. It can be concluded, curcumin and its derivatives in keto-enol show better potencies as active materials in dye sensitized solar cells than diketo while six anthocyanin compounds, show good potencies. The low density of LUMO in anchoring group causes the low conversion efficiency solar cell when curcuminoid and anthocyanin are used as photosensitizer.