https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19296 OC) and short circuit current (J_SC) have increased. The increased V_OC is attributed to increased electron lifetimes due to a steric blocking effect. Analysis of the increased short circuit current (ΔJ_SC) showed that only less than 10% of ΔJ_SC originates from increased light absorption under simulated air mass 1.5 illumination, while the rest of the improvements are attributed to a steric effect enhancing the electron injection efficiency. These results suggest that developing non-conjugated multichromophoric dyes can lead to simultaneous increases in both the photocurrent and the photovoltage of dye-sensitized solar cells.]]> Sat 24 Mar 2018 07:56:08 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:26340 meso groups have been studied with UV-vis, resonance Raman, emission spectroscopies, and density functional theory (DFT) calculations. Dye-sensitized solar cells (DSSCs) of these materials have also been fabricated and their performance parameters measured. DFT calculations show perturbation of frontier molecular orbitals, and redox-active substituents cause greater perturbation than nonredox active substituents. All substituents cause a broadening of the B band, as is common for substituted porphyrins. TD-DFT calculations and resonance Raman spectroscopy suggest the donor and acceptor substituents play a small role in transitions of the B band. The meso donor substituent is electronically isolated and does not significantly perturb the molecular orbitals (MOs), while the meso cyanoacrylic acid TiO₂ binding group has a much larger effect on the e_g MO in particular. However, in the oxidized porphyrin species, the hole is located on the meso substituent, localizing it away from the semiconductor surface, which should reduce recombination and also improve performance. They show modest efficiency when incorporated into solar cells; however, the pattern of behavior is consistent with localization of charge at the meso unit.]]> Sat 24 Mar 2018 07:35:57 AEDT ]]>