Abstract:
Photoelectrochemical cells face fundamental performance-stability trade-offs that conventional synthesis approaches cannot overcome. This perspective demonstrates how physical vapor deposition delivers orders of magnitude higher energies (103–105 meV/atom) compared to chemical-based methods (∼25–60 meV/atom), enabling precise stoichiometric and structural control in multinary metal-oxide photoelectrodes. However, optimal crystallization requires high-temperature postprocessing exceeding substrate’s limits. Rapid-photonic-annealing achieves heating-rates of 102–107 versus ∼0.01–1 K/s for conventional conduction/convection heating, creating thermal-nonequilibrium conditions that enable high-temperature crystallization while preserving substrate integrity with dramatically reduced energy consumption and enhanced processing versatility. This synergistic combination of energetic deposition with ultrafast annealing produces superior films with reduced grain-boundary density, minimized defects, and enhanced crystallinity. Case-studies of metal-oxides demonstrate enhanced photoelectrochemical stability and performance compared to conventional processing routes. Proof-of-concept SnWO4 validation achieves phase-pure crystallization within several milliseconds─six-orders-of-magnitude faster than furnace annealing. This framework represents a paradigm-shift, simultaneously addressing efficiency, stability, and scalability requirements for practical photoelectrochemical systems.
