Exceptional Spatial Variation of Charge Injection Energies on Plasmonic Surfaces

Abstract

Charge injection into a molecule on a metallic interface is a key step in many photoactivated reactions. We employ the many-body perturbation theory and compute the hole and electron injection energies for CO 2 molecule on an Au nanoparticle with ∼3,000 electrons and compare it to results for idealized infinite surfaces. We demonstrate a surprisingly large variation of the injection energy barrier depending on the precise molecular position on the surface. Multiple "hot spots," characterized by low energy barriers, arise due to the competition between the plasmonic coupling and the degree of hybridization between the molecule and the substrate. The charge injection barrier to the adsorbate on the nanoparticle surface decreases from the facet edge to the facet center. This finding contrasts with the typical picture in which the electric field enhancement on the nanoparticle edges is considered the most critical factor.

Efficient Quasiparticle Determination beyond the Diagonal Approximation via Random Compression

“…The visual changes are, however, not indicative of the magnitude of the QP energy shift accomplished, and hence, these are better inspected in Figure . In turn, stronger localization of HOMO is typically associated with its energy decrease. , These observations are thus in line with what the MBPT should accomplish and underline the need for a more appropriate treatment of surface phenomena. Without studying the change in the orbital structure itself, the large downward energy shift, accomplished by accounting for interactions with higher energy states, emphasizes the importance of taking GW calculations beyond the diagonal approximation.…”

“…Single particle states are frequently used in the study of excitation phenomena such as photoionization, electron injection, and generally optical transitions. − The physical interpretation of such single particle states often depends on the specific type of observables. , In particular, Dyson orbitals, which correspond to the probability amplitude distribution of a specific electron or hole excitation (i.e., quasiparticle state), are directly accessible via orbital tomography and provide insights into the relation between energies and real-space distribution of single particle excitation. , This has fundamental implications for chemistry–e.g., hybridization of quasiparticles on surfaces governs the propensity for direct injection of an electron . These are just a few compelling reasons to account for the physically meaningful orbital distributions, especially for problems concerning (chemical) interfaces.…”