Synthesis of Metal Doped Strongly Confined Halide Perovskite Nanocrystals Under Ambient Conditions

Halide perovskite (HP) semiconductor nanocrystals (NCs) hold great promise for optoelectronic applications due to their high photoluminescence (PL) quantum yields and energetic tunability via composition and size. Substitution of the divalent metal ion can improve the native properties of the HP NCs, where the radiative rate or NC stability can improve, or the metal dopant can introduce novel properties, such as ferromagnetism. Synthesis of strongly confined doped HP NCs has been difficult historically, as hot injection techniques commonly produce polydisperse, large HP NCs.<br/><br/>In contrast, our novel synthetic method, which builds upon new work from the Kovalenko group, allows for facile doping of various divalent metal ions (Ni, Zn, Mn), which can be performed at room temperature and in ambient conditions. Here, we synthesize a variety of CsPbCl₃ NC sizes, with variable concentrations of metal dopants. Using Mn as a case study, we find that we can vary the Mn composition from 0.1 - 0.5% in NCs ranging in size from ~4 - 12 nm. Further, we find that Mn incorporates into the NC lattice, resulting in a variety of interesting photophysical phenomena, which we quantify using ultrafast transient absorption.