Monodisperse Bismuth-Halide Double Perovskite Nanocrystals Confined in Mesoporous Silica Templates

Abstract

Metal halide perovskites have fascinating electronic properties and have already been implemented in various devices. Although the behavior of the properties of lead halide perovskite nanocrystals has been studied, the properties of lead-free perovskite nanocrystals are less wellunderstood because synthesizing them is still very challenging. Here, a simple and popularizable method has been demonstrated to grow monodisperse bismuth-halide double perovskite nanocrystals, Cs 2 AgBiBr 6 (1), inside three kinds of mesoporous silica templates. The size and morphology of nanocrystals depend on the structure and pore size of the template. Structural analysis shows that the nanocrystals of various sizes and morphologies retain the crystal structure of bimetallic perovskite. 1 exhibits different morphologies in the silicon channels of three templates: square nanoparticles in KIT-6, spherical and rodlike particles in SBA-15, and nanowires in MCM-41. UV−vis−NIR and photoluminescence measurements show us the variation of band gap and carrier recombination time due to quantum confinement of nanocrystals in mesoporous silicon materials. The band gaps of nanocrystals in the template exhibit an obvious blue shift compared with that of the bulk sample, and the carrier recombination time is significantly shortened. We show that mesoporous silicon templates can be used to prepare lead-free perovskite nanocrystals, and the controllable preparation of nanocrystals can be achieved by the template's own characteristics. This provides a new idea for us to find new functional materials of lead-free metal halide solidstate light-emitting diodes.

Recent Advances in Cs2AgBiBr6-Based Halide Double Perovskites as Lead-Free and Inorganic Light Absorbers for Perovskite Solar Cells

“…Isopropanol was injected as the antisolvent to form the precipitate of nanocrystals . Moreover, different morphologies (square nanoparticles, spherical and rod-like particles, and nanowires) of monodispersed Cs 2 AgBiBr 6 nanocrystals were prepared using corresponding silica templates (KIT-6, SBA-15, MCM-41) …”

Aerobic Oxidation of Fluorene to Fluorenone over Copper-Doped Co3O4 with a High Specific Surface Area

“…Figure shows the low-angle XRD patterns of KIT-6. The peaks at around 1° were attributed to the (211) and (220) reflections of KIT-6, indicating the existence of ordered cubic structural Ia3d. , …”

“…The peaks at around 1°were attributed to the (211) and (220) reflections of KIT-6, indicating the existence of ordered cubic structural Ia3d. 30,31 N 2 adsorption−desorption isotherms of KIT-6 (Figure 2a) showed the type IV isotherm with a H1 hysteresis loop, suggesting ordered channel-like pores with narrow pore size distribution. 30,31 The specific surface area of KIT-6 was 842 m 2 • g −1 (Table 1) and the BJH pore diameter distribution of KIT-6 was between 5 and 8 nm (Figure 2b).…”

“…30,31 N 2 adsorption−desorption isotherms of KIT-6 (Figure 2a) showed the type IV isotherm with a H1 hysteresis loop, suggesting ordered channel-like pores with narrow pore size distribution. 30,31 The specific surface area of KIT-6 was 842 m 2 • g −1 (Table 1) and the BJH pore diameter distribution of KIT-6 was between 5 and 8 nm (Figure 2b).…”

Nanoconfined Crystallization for High‐Efficiency Inorganic Perovskite Solar Cells

“…To our knowledge, the easily obtainable mesosilica family covering SBA‐15, MCM‐41, KIT‐6, MSU‐H, and MCM‐48 has been incorporated in perovskite nanocrystals to benefit photoluminescence (PL) performance due to the nanoconfined crystallization effect. [ 34–36 ] However, this appealing strategy has not been applied in the photovoltaic conversion field because the size of the aforementioned mesosilica is considerably large for the thin perovskite film, and the nanofluidic effect will impede the insertion of perovskite precursors. [ 37 ] Therefore, we synthesized the Zr‐doped SBA‐15 (named as ZrSBA‐15) nanoplatelets and applied it in inorganic PSCs because it possesses similar pore structure but suitable size compared with the other mesoporous silica materials.…”