Compound doping enables efficient CsPbBr3 nanocrystal light emitting diodes

All-inorganic cesium-based perovskite nanocrystals (PeNCs) attract much attentions in displays due to their facile synthesis protocol and superior luminous performance, while material instability hinders their practical applications. Herein, by inducing a multi-functional dopant, i.e., SrBr2, into the perovskite precursor solution, the as-formed SrBr2-doped CsPbBr3 NCs possess purer phases, suppressed defects and hydrophobic surfaces, which leads to a high photoluminescence quantum yield of ∼90 %, as well as much improved moisture stability. Benefiting from dopant passivation and improved luminescence properties, the doped CsPbBr3 light emitting diodes show five times and two times of current efficiency and external quantum efficiency improvements, respectively, in comparison to their undoped counterparts.