Reactive High-Energy-Per-Molecule Oxygen Clusters for Reliable ToF-SIMS Depth Profiling of Hybrid Nanomaterials

Hybrid materials that integrate organic and inorganic components within a single architecture pose significant challenges for depth profiling due to their compositional complexity. Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) offers spatially resolved chemical information coupled with high sensitivity, but conventional sputtering conditions typically fail to simultaneously preserve organic molecular information while efficiently eroding inorganic materials. Here, we report a previously unexplored approach for the characterization of such complex hybrid systems. By employing a reactive oxygen gas cluster ion beam (O2-GCIB) operated at high-energy-per-molecule, we achieve, for the first time, consistent and reliable depth profiling of both layered and blended hybrid structures comprising molybdenum oxide (MoO₃) and N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPD). High-energy per molecule oxygen clusters enhance the sputtering yield of the inorganic phase, also mitigating chemical degradation in the organic component, helping to preserve molecular information. This dual functionality effectively overcomes the limitations observed with argon-based clusters establishing a new paradigm for the molecular analysis of hybrid interfaces.