Luminescence and nonlinear optical properties of stable MAPbBr₃ quantum dots in SiO₂ mesopores

Abstract

MAPbBr3 quantum dots in SiO2 mesopores ([Formula: see text][Formula: see text]nm) were prepared by the spin-coating method, and their luminescence and nonlinear optical properties were studied by time-resolved photoluminescence (TRPL) and Z-scan techniques. The results showed that the absorption and photoluminescence peaks are at 464[Formula: see text]nm and 476[Formula: see text]nm, respectively. The TRPL spectroscopy showed two relaxation processes, a short lifetime (1.04[Formula: see text]ns) and a long lifetime (4.49[Formula: see text]ns), attributed to the trap–capture recombination and the electron–hole radiative recombination, respectively. Two-photon absorption (TPA) coefficient was 529[Formula: see text]cm/GW at 800[Formula: see text]nm. The nonlinear signal changed from TPA to saturable absorption with increase in light intensity.