Sequential series multijunction dye-sensitized solar cells (SSM-DSCs), which are mechanically stacked single illuminated area DSC devices wired in series, are reported to have the highest photovoltages obtained from a single illuminated area DSCs. The use of multiple photoactive films under one area within the SSM-DSC framework is made possible by fine tuning the thickness of TiO₂ in each device and judicious dye selection to allow for excellent light distribution among the films, termed as “photon management”. Photovoltages (V_oc) ranging from 1.9-4.7 V are observed for SSM-DSCs fabricated from 2-5 stacked subcells constructed with metal-free organic dyes and cobalt redox shuttles. In SSM-DSCs photon management approach allows for incorporation of materials designed to use the maximal potential energy of photons in each region of the solar spectrum. Further optimizations through the inclusion of antireflection film and replacing organic dyes with efficient metal complex dyes, have achieved up to ~10% power conversion efficiency for three cell based SSM-DSC with photovoltage of 2.2 V for single illuminate area devices. As the results of these optimizations, SSM-DSCs were found have up to 6.5% solar to fuel (STF) efficiency for water splitting compared to 3% of STF previously reported. Studies are underway to characterize optimized SSM-DSCs for CO₂ reduction, previously SSM-DSCs showed 2% STF efficiency (2.7% including H₂ production) for the reduction of CO₂ to CO with IrO₂ and Au₂O₃ electrocatalysts without bias for the first time with DSCs.