Ultrafast charge carrier dynamics and photoluminescence of CsPbBr3−xIx quantum dots in boro‐germanate glasses

Abstract CsPbBr 3− x I x quantum dots were precipitated in boro‐germanate glasses with various Br/I ratios by the melt‐quenching method. When the heat treatment temperature ( T H ) increased from 480 to 550°C, more I − entered the perovskite crystal lattice, resulting in lattice expansion, the X‐ray diffraction peaks of CsPbBr 1.5 I 1.5 glasses shifted to small angles. The high concentration of I − entered into the perovskite crystal lattice, decreasing the bandgap. The photoluminescence (PL) peaks of CsPbBr 1.5 I 1.5 glasses redshifted from 577 to 620 nm, the PL peaks of CsPbBrI 2 glasses shifted from 614 to 636 nm, and the PL peaks of CsPbBr 0.5 I 2.5 glasses shifted from 650 to 672 nm. As the ratio of Br/I reduced from 2.5/0.5 to 0.5/2.5, the PL lifetime of CsPbBr 3− x I x glass increased from 2.08 to 74.5 ns. With the delay time from 1 to 1500 ps, the carriers gradually accumulated in the band‐edge state, and the bleaching signal intensity increased. Then more and more carriers returned to the ground state through radiative or nonradiative recombination, the bleaching signal intensity decreased.