A light in the dark

The in silico optimization of solar energy conversion devices in which light is used to separate charge and generate power requires advanced quantum mechanical approaches to describe the photon-harvesting component and the initial charge-propagation process in the excited state.

Computing excited states, however, is highly demanding for electronic structure methods, which often struggle to ensure accuracy or treat the large, relevant system sizes. To overcome these limitations, we work in the sophisticated framework of many-body quantum Monte Carlo (QMC) methods, we have been actively developing in recent years for the accurate treatment of excited states in complex systems.

Here, we propose to professionally structure and further accelerate our methodology for energy-related applications into a set of open and re-usable software tools addressing three key elements of QMC simulations: fast computation of observables, effective non-linear optimization schemes, and efficient graphics-processing-units kernels.

With these enhanced tools, we will in parallel proceed to establish a computational protocol to optimize the primary elements of a dye-sensitized solar cell and provide robust reference data for the characterization of one of the major limitations in efficiency, namely, the charge-recombination process at the interface between dye and semiconductor.