Uncovering the Role of Trioctylphosphine on Colloidal and Emission Stability of Sb-Alloyed Cs<sub>2</sub>NaInCl<sub>6</sub> Double Perovskite Nanocrystals
Razi Ahmad, Lukáš Zdražil, Sergii Kalytchuk, Alberto Naldoni, Andrey L. Rogach, Patrik Schmuki, Radek Zbořil, Štěpán Kment
Abstract
-generated trioctylphosphonium chloride and benzoyl trioctylphosphonium chloride serve as highly reactive halide sources, while benzoyl trioctylphosphonium and oleylammonium cations together with the oleate anion serve as surface capping ligands, which are bound strongly to the PNC surface. The tightly bound ionic pair of oleylammonium oleate and benzoyl trioctylphosphonium chloride/oleate ligands allows one to obtain monodispersed bright-blue-emitting PNCs with high photoluminescence quantum yields exceeding 50% at an optimum Sb content (0.5%), which also exhibit long-term colloidal stability. The approach based on dual cationic ligand passivation of double PNCs opens the doors for applications in other systems with a potential to achieve higher stability along with superior optical properties.