INVESTIGASI TD-DFT PADA STRUKTUR ELEKTRONIK DAN SPEKTRUM ABSORPSI KOMPLEKS cis-(Ru(H2dcbpy)2(SCN2) DAN cis-(Ru(H2dcbiq)2(SCN2) FASA GAS DAN FASA LARUTAN ETANOL UNTUK APLIKASI DSSC

• Main Author: DELIANA DEWI SUNDARI (NIM : 20510050); Pembimbing : Dr. Muhamad A. Martoprawiro, CITRA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/15238
• Institution: Institut Teknologi Bandung

Dye sensitized solar cell (DSSC) is one kind of low-cost third generation solar cell which employed organic/complex “dye” molecule as photon catcher. Ruthenium polipyridyl complex and its derivatives are known as dye capable to <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> yield high overall cell efficiency. Two kinds of ruthenium polipyridyl derivatives studied computationally in this research were cis-(Ru(H2dcbpy)2(SCN)2) and <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> cis-(Ru(H2dcbiq)2(SCN)2) (H2dcbpy = 2,2’-bipyridine-4,4’-dicarboxylic acid, H2dcbiq = 2,2’-biquinoline-4,4’-dicarboxylic acid). All calculations were carried <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> out with Gaussian03 code, using Becke, three-parameter, Lee-Yang-Parr (B3LYP) hybrid functional DFT and TDDFT for ground state geometry optimization and excited states calculations respectively. Two kind of basis set were used for comparation, i.e. 3-21G for all elements, and mixed basis sets (GENECP) with pseudopotentials for Ru (SDD MWB28 for Ru and 6-31G for the remaining atoms). Tomasi’s Polarized Continuum Model (PCM) was used for modelling the <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> complex in ethanol solution. Combination of GENECP basis set with PCM in cis-(Ru(H2dcbpy)2(SCN)2) calculation achieve the best approach regarding to experimental absorption spectra. The last two maximum absorption peaks <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> dominated by charge transfer excitation are blue shifted in ethanol solution with respect to those in the gas phase. Electronic polarization between complex and solvent caused the structure to relax, permitting a greater charge separation. This method is then used to calculate absorption spectra of cis-(Ru(H2dcbiq)2(SCN)2). Absorption spectra of both complexes were compared and it was found that cis-(Ru(H2dcbiq)2(SCN)2) has absorption peaks at larger wavelength than cis-(Ru(H2dcbpy)2(SCN)2). Absorption peaks of cis-(Ru(H2dcbq)2(SCN)2) complex are located at a wavelength of 601 nm, 430 nm, 346 nm, and 292 nm, whereas the cis-(Ru(H2dcbpy)2(SCN)2) complex (N3 sensitizer) absorption peaks are located at a wavelength of 545 nm, 431 nm, 372 nm , and 296 nm. Based on these results, the complex cis-(Ru(H2dcbq)2(SCN)2) has the possibility of generating higher value of DSSC cells efficiency compared to cis-(Ru(H2dcbpy)2(SCN)2) (N3sensitizer).