Efficient Interfacial Synthesis Strategy for Perovskite CsPbBr ₃ Nanorods in the Biphase Solution

1D APbX 3 (A = Cs, MA, FA, X = Cl, Br, I) nanorods (NRs) show potential for the future integrated optoelectronic devices as the ideal building blocks due to their outstanding optoelectronic performances. However, there is still a lack of high‐efficiency controllable strategies to synthesize CsPbX 3 NRs. An interfacial synthesis strategy is shown here to fabricate CsPbBr 3 NRs by inserting Pb 2+ into postsynthetic CsBr nanocrystals in vortex method at the water‐hexane interface. The water phase can intrinsically separate from the hexane phase in such a system and take away excess Pb 2+ and other side reaction salts. Additionally, without additional ligand assisted growth, the whole reaction system could result in a very clean surface of CsPbBr 3 NRs, eliminating the further purification process. The new approach for interfacial synthesis paves the way for efficient synthesis of CsPbBr 3 nanorods.