Enhancing orange-red emission by doping/codoping CsPb2Br5 with cations through a room-temperature aqueous-phase synthesis†

Despite the rising advances in the field of all-inorganic CsPb₂Br₅-based materials and their photoelectronic applications, the exploitation of facile synthetic procedures and enhancement of optical properties remain challenging. Herein, we report a facile room-temperature aqueous phase synthesis of orange-red-emitting cation-doped and codoped CsPb₂Br₅ materials with enhanced photoluminescence (PL) performance and stability. Only a very weak broad PL peak at around 618 nm is observed in the undoped CsPb₂Br₅ microsheets. However, doping with Cu and codoping with Cu/Mn, Cu/Zn or Cu/Cd significantly enhance the PL intensity of the resulting CsPb₂Br₅-based samples. The stability of the representative Cu-doped and various codoped CsPb₂Br₅ samples is evaluated under various conditions such as soaking in water, high temperature up to 150 °C, and an ambient environment at room temperature. This work provides a facile and cost-effective path for large-scale and controlled synthesis of orange-red emissive CsPb₂Br₅-based materials with enhanced optical performances, excellent environmental stability, and potential in LEDs.