The use of highly tuneable, easily processable organic molecules for photovoltaics holds great promise for future low-cost and low-carbon energy production. One of the most powerful applications is in singlet-fission-sensitized photovoltaics (SFPV), which offers the potential to double the photocurrent collected in the blue-green region of the solar spectrum. Singlet fission (SF) is a manifestation of the unique spin properties of organic materials: in this phenomenon, a spin-singlet excited state separates into two low-energy spin-triplet excited states. In solar cells, this process can more efficiently harness high-energy photons to overcome thermalization limits. The impact of this technique would be especially profound in hybrid devices encompassing a SF ‘sensitizer’ and silicon. However, the precise mechanism of SF remains unclear, and the dynamics of triplet excitons and organic-inorganic interfaces are poorly understood. A clear understanding of the creation and the transfer of triplet excitons in these hybrid systems is necessary to realize the potential of SFPV. Recent studies have indicated the importance of nuclear dynamics for photophysical processes in organic materials. For instance it was found that SF is driven by vibronic coupling in pentacene. We will use pump-IR push-probe techniques to stimulate particular vibrational modes prior to and during triplet formation and investigate the nature of such vibronic coupling and its broader applicability. We aim to identify vibrational modes which help or hinder the SF rate. These techniques will also be extended to the transfer of triplet excitons from organic to inorganic material, with a focus on the vibrational properties of the triplet ‘host’ material and the ligands passivating the inorganic surface. The combination of these results will give a unified picture of the role of vibrational energy in SFPV dynamics and should lead to better photovoltaic devices in which excitations ‘surf’ on a wave of vibrations to the interface.