Tunable Electrochemiluminescence Properties from Mixed-Monovalent Cations CsPbBr3 Perovskite Nanocrystals

Herein we demonstrate a simple approach for tuning the elecrochemiluminescence (ECL) properties of CsPbBr3 perovskite nanocrystals (NCs) by mixed-monovalent cations. By replacing part of Cs+ by Rb+, a series of RbxCs1-xPbBr3 NCs were obtained. They exhibit narrow ECL emission peak with the full width at half-maximum about 26~34 nm. After continuously injecting holes to produce different charged state radicals, an annihilation ECL was observed, implying the as-prepared RbxCs1-xPbBr3 NCs are in electron-rich state. In the presence of 2-dibutyaminoethanol as co-reactant, strong andodic ECL of RbxCs1-xPbBr3 NCs was obtained. From CsPbBr3 NCs to CsPbBr3 NCs, the ECL peak potential position was moved from 1.25 V to 1.80 V with the ECL spectrum peak shifted from 512 to 468 nm, respectively, indicating the tunable ECL properties. The Rb0.2Cs0.8PbBr3 NCs have higher ECL intensity than CsPbBr3 NCs.