Synthesis Of CsPbBr3 Perovskite Nanocrystals Research Articles

Facile room-temperature colloidal synthesis of CsPbBr3 perovskite nanocrystals by the Emulsion-based ligand-assisted reprecipitation approach: Tuning the color-emission by the demulsification process

Although perovskite nanocrystals (PNCs) have established themselves as the future of light-emitting devices and the photovoltaic industry, their synthesis protocols have always been debated. In this study, CsPbBr3 NCs were prepared using an emulsion-based ligand assisted reprecipitation (emulsion LARP) approach. This synthesis approach presented a facile process for preparing CsPbBr3 NCs by removing the hassles and complications experienced in the hot-injection and conventional LARP methods. Emulsion LARP also presented a unique advantage of avoiding the over use of polar solvents, heat-treatments of the precursor solutions, requirement of inert atmosphere, during the synthesis process. Acetone was used as the demulsifier to precipitate NCs from the solution. The introduction of acetone during the synthesis not only improved the photoluminescence intensity of the NCs, but also brought about color-tuning in their emission. By varying the acetone concentration, the color emission was tuned from green to blue. The PNCs prepared by this synthesis protocol demonstrated good photostability under near ultraviolet light exposure and their photoluminescence quantum yield decreased from 64% to 47% over a span of one year.

Facile Room-Temperature Colloidal Synthesis of Cspbbr3 Perovskite Nanocrystals by the Emulsion-Based Ligand-Assisted Reprecipitation Approach: Tuning the Color-Emission by the Demulsification Process

Facile Room-Temperature Colloidal Synthesis of Cspbbr3 Perovskite Nanocrystals by the Emulsion-Based Ligand-Assisted Reprecipitation Approach: Tuning the Color-Emission by the Demulsification Process

Solution-Processed Fabrication of Light-Emitting Diodes Using CsPbBr3 Perovskite Nanocrystals

The sonochemical synthesis of CsPbBr3 perovskite nanocrystals (PNCs) is an attractive method for the large-scale synthesis and low-cost production of PNC at low temperature; however, there are no r...

Revealing the Formation Mechanism of CsPbBr3 Perovskite Nanocrystals Produced via a Slowed-Down Microwave-Assisted Synthesis.

We developed a microwave-assisted slowed-down synthesis of CsPbBr3 perovskite nanocrystals, which retards the reaction and allows us to gather useful insights into the formation mechanism of these nanoparticles, by examining the intermediate stages of their growth. The trends in the decay of the emission intensity of CsPbBr3 nanocrystals under light exposure are well correlated with their stability against decomposition in TEM under electron beam. The results show the change of the crystal structure of CsPbBr3 nanocrystals from a deficient and easier to be destroyed lattice to a well crystallized one. Conversely the shift in the ease of degradation sheds light on the formation mechanism, indicating first the formation of a bromoplumbate ionic scaffold, with Cs-ion infilling lagging a little behind. Increasing the cation to halide ratio towards the stoichiometric level may account for the improved radiative recombination rates observed in the longer reaction time materials.

Shape-Controlled Synthesis of All-Inorganic CsPbBr3 Perovskite Nanocrystals with Bright Blue Emission.

We developed a colloidal synthesis of CsPbBr3 perovskite nanocrystals (NCs) at a relative low temperature (90 °C) for the bright blue emission which differs from the original green emission (∼510 nm) of CsPbBr3 nanocubes as reported previously. Shapes of the obtained CsPbBr3 NCs can be systematically engineered into single and lamellar-structured 0D quantum dots, as well as face-to-face stacking 2D nanoplatelets and flat-lying 2D nanosheets via tuning the amounts of oleic acid (OA) and oleylamine (OM). They exhibit sharp excitonic PL emissions at 453, 472, 449, and 452 nm, respectively. The large blue shift relative to the emission of CsPbBr3 bulk crystal can be ascribed to the strong quantum confinement effects of these various nanoshapes. PL decay lifetimes are measured, ranging from several to tens of nanoseconds, which infers the higher ratio of exciton radiative recombination to the nonradiative trappers in the obtained CsPbBr3 NCs. These shape-controlled CsPbBr3 perovskite NCs with the bright blue emission will be widely used in optoelectronic applications, especially in blue LEDs which still lag behind compared to the better developed red and green LEDs.