LAUSR

The precise control of semiconductor polarity in nanocrystals (NCs) is crucial for optimizing device performance in various optoelectronic applications. In this study, it is shown that Ag⁺, added post-synthetically to InAs NCs using an AgNO3 solution, can induce either n-type or p-type doping of the solid, depending on the intrinsic polarity of the host and the dopant concentration. In n-type InAs NCs, Ag⁺ consistently acts as an interstitial n-type dopant, shifting the conduction band minimum closer to the Fermi level. Conversely, in p-type InAs NCs (innately doped with Zn during synthesis), Ag⁺ initially exhibits a p-type doping effect at low concentrations by forming surface dipoles but transitions to an n-type doping effect at higher concentrations through interstitial incorporation. These results offer a unified understanding of the intricate and adjustable doping behavior of Ag⁺ in colloidal NC systems and present new opportunities for post-synthetic polarity engineering in III-V nanomaterials.