Solar-to-Chemical Energy Conversion with Advanced Nitride Semiconductors

ended

As photovoltaic technologies gain prominence, an outstanding challenge is the development of systems that can robustly store solar energy with high density. Within this context, the capture of sunlight and its direct conversion to chemical fuels in artificial photosystems provides a promising route for sustainably meeting future energy demands. However, a central challenge is the lack of systems that can efficiently direct light excitations towards desired chemical products with high efficiency and stability under harsh reaction conditions. In recent years, advances in using thin films to protect chemically sensitive light absorbers have relaxed the requirement for intrinsically stable semiconductors and motivate an entirely new perspective for rational design of materials and interfaces. Within this context, SECANS aims to create the scientific basis for solar-to-chemical devices that achieve unprecedented combinations of efficiency and stability, enabled by targeted exploration and rational optimization of an underexplored class of materials – transition metal nitride semiconductors. The electronic structures of these materials can enable a favourable balance between large charge carrier mobility and high defect tolerance. However, due to the high stability of molecular nitrogen, the expansive range of possible nitrides is largely unexplored and their basic properties poorly understood. SECANS overcomes these challenges through an interdisciplinary approach that couples non-equilibrium semiconductor deposition and newly developed interface engineering methods, supported by advanced operando spectroscopies, to enable high efficiency light harvesting systems with self-healing interfaces. This project will develop novel nitride semiconductors optimized for solar-to-chemical energy conversion, elucidate the roles of defects and disorder on competitive kinetics within photochemical reaction cycles, and provide new insights into the science of photochemical stability.