A high quality and quantity hybrid perovskite quantum dots (CsPbX₃, X= Cl, Br and I) powders synthesis via ionic displacement

Recently, all-inorganic perovskites CsPbX₃ (X= Cl, Br and I) quantum dots (QDs) have drawn great attentions because of their PL spectra tunable over the whole visible spectral region (400-700 nm) and adjustable bandgap, which revealed a promising potential on the field of photoelectronic devices, such as solar cells, LEDs and sensors. In this paper, CsPbX₃ QDs and hybrid QDs, CsPbClxBr3-x and CsPbBrxI3-x were synthesized via one-step and two-step methods comparably. The optical bandgaps of CsPbCl₃, CsPbBr₃, and CsPbI₃, were calculated as 3.08, 2.36, and 1.73eV, respectively, based on the Tauc's equation and UV absorption spectra. Ionic displacement and phase transformation occurred during the mixing process were found based on the monitoring of PL spectra and HRTEM characterization. The long-Term stability, dried, high quality and two-dimensional hybrid CsPbBrxI_3-x QDs powders could be achieved via the two-step method. Polar solution inductions were used to wash and purify the CsPbX₃ QDs, which help obtain of various compositions and well crystallize all-inorganic perovskites QDs powders.