After the mixture turned orange (~20 min), which indicates the formation of CsPbBr3 microcrystals, the crystals were dissolved by heating to 145 ˚C and stirring for 40 min. Next, 1 mL of DMF was added, and the solution became transparent. This solution was added dropwise into the ligands blend (OA=125 µL, OLAm=125 µL, and ODE=1.25 mL). Lastly, a swift injection of acetone (5 mL) resulted in a gradual color change from white to green solution and the formation of Cs4PbBr6 NCs. The synthesized NCs were centrifuged at 3500 rpm for 5 min and redispersed in 1 mL of toluene.