2 research outputs found

    Original Core–Shell Structure of Cubic CsPbBr<sub>3</sub>@Amorphous CsPbBr<sub><i>x</i></sub> Perovskite Quantum Dots with a High Blue Photoluminescence Quantum Yield of over 80%

    No full text
    All-inorganic perovskite cesium lead halide quantum dots (QDs) have been widely investigated as promising materials for optoelectronic application because of their outstanding photoluminescence (PL) properties and benefits from quantum effects. Although QDs with full-spectra visible emission have been synthesized for years, the PL quantum yield (PLQY) of pure blue-emitting QDs still stays at a low level, in contrast to their green- or red-emitting counterparts. Herein, we obtained core–shell structured cubic CsPbBr<sub>3</sub>@amorphous CsPbBr<sub><i>x</i></sub> (A-CsPbBr<sub><i>x</i></sub>) perovskite QDs via a facile hot injection method and centrifugation process. The core–shell structure QDs showed a record blue emission PLQY of 84%, which is much higher than that of blue-emitting cubic CsPbBr<sub>3</sub> QDs and CsPbBr<sub><i>x</i></sub>Cl<sub>3–<i>x</i></sub> QDs. Furthermore, a blue-emitting QDs-assisted LED with bright pure blue emission was prepared and illustrated the core–shell QDs’ promising prospect in optoelectrical application

    High-Efficiency Pure-Red CsPbI<sub>3</sub> Quantum Dot Light-Emitting Diodes Enabled by Strongly Electrostatic Potential Solvent and Sequential Ligand Post-treatment Process

    No full text
    Efficient pure-red emission light-emitting diodes (LEDs) are essential for high-definition displays, yet achieving pure-red emission is hindered by challenges like phase segregation and spectral instability when using halide mixing. Additionally, strongly confined quantum dots (QDs) produced through traditional hot-injection methods face byproduct contamination due to poor solubility of metal halide salts in the solvent octadecene (ODE) at low temperatures. Herein, we introduced a novel method using a benzene-series strongly electrostatic potential solvent instead of ODE to prevent PbI2 intermediates and promote their dissolution into [PbI3]−. Increasing methyl groups on benzene yields precisely sized (4.4 ± 0.1 nm) CsPbI3 QDs with exceptional properties: a narrow 630 nm PL peak with photoluminescence quantum yield (PLQY) of 97%. Sequential ligand post-treatment optimizes optical and electrical performance of QDs. PeLEDs based on optimized QDs achieve pure-red EL (CIE: 0.700, 0.290) approaching Rec. 2020 standards, with an EQE of 25.2% and T50 of 120 min at initial luminance of 107 cd/m2
    corecore