The objective of this work is to characterize the effect of nanowire length on the ionization potential (IP) of a series of Ag nanowires. The ionization potential can provide important information about the density of states and energies near valence band edge which can provide insight into conductivity and electron transport processes in nanowires. In this work, we present a first-principles computational investigation of the effect of length of linear Ag clusters and nanowires on the ionization potential. This was achieved by combining Green's function theory with the recently-developed stochastically-enumerated stratified sampling of molecular orbitals (SESSMO) method for solving the Dyson equation. The results from a series of Ag<sub>10</sub> to Ag<sub>100</sub> nanowires showed that the IP scale non-linearly with respect to length of the wire. This non-linearity can be attributed to the sharp increase in the density of states near the valence edge due to increasing length. The trend in the IPs as a function of nanowire length observed from using the SESSMO method were found to be greatly different from the trend displayed when using the Koopman's approximation to the ionization potentials. Therefore, electron-electron correlation was found to be important and IPs calculated from the Dyson equation were found to be different from Koopman's approximation IPs. The closing of the HOMO-LUMO gap and contributions from the unoccupied states were found to be a critical factor and highlights the need for a high-level method for understanding length dependent trends of nanowires.

Characterization of electron detachment energies in silver nanowires

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.