Gold‐Doping Effect on Two‐Photon Absorption and Luminescence of Atomically Precise Silver Ligated Nanoclusters
Anna Pniakowska, Kumaranchira Ramankutty Krishnadas, Patryk Obstarczyk, Martina Perić Bakulić, Željka Sanader Maršić, Vlasta Bonačić‐Koutecký, Thomas Bürgi, Joanna Olesiak‐Bańska
Abstract
Abstract Noble metal nanoclusters allow for the atomically‐precise control of their composition. However, to create nanoclusters with pre‐defined optical properties, comprehensive description of their structure‐property relation is required. Here, we report the gold atom doping impact on one‐photon and two‐photon absorption (TPA) and luminescence properties of ligated silver nanoclusters via combined experimental studies and time‐dependent density functional theory simulations (TD‐DFT). We synthesized a series of Ag 25− x Au x (DMBT) 18 nanoclusters where x =0, 1 and 5–10. For Ag 24 Au 1 (DMBT) 18 we demonstrate that the presence of the central Au dopant strongly influences linear and non‐linear optical properties, increasing photoluminescence quantum yield and two‐photon brightness, with respect to undoped silver nanoclusters. With improved TPA and luminescence, atomically‐precise AuAg alloys presented in our work can serve as robust luminescent probes e.g. for bioimaging in the second biological window.