Halide perovskites and select molecular semiconductors promise a future in which solar cells are spray-coated from solution onto flexible substrates — think lightweight modules for drones and satellites, semi-transparent photovoltaic windows, or panels woven directly into buildings and wearables. Turning that promise into long-lived, low-carbon devices requires us to understand, at the atomic scale, how charges are generated, transported, and lost inside these soft, disordered materials.

We combine materials synthesis, ultrafast optical spectroscopy, and multi-dimensional microscopy to resolve carrier dynamics from femtoseconds to seconds and from nanometres to centimetres. The resulting mechanistic picture feeds directly into chemical and processing design rules for the next generation of efficient, cheap, and flexible photovoltaics.