Yongmin Duan

Bio: Yongmin Duan is an academic researcher from China Jiliang University. The author has contributed to research in topics: Quantum dot & Luminescence. The author has an hindex of 4, co-authored 11 publications receiving 54 citations.

Nanocrystalline structure control and tunable luminescence mechanism of Eu-doped CsPbBr3 quantum dot glass for WLEDs.

Abstract: CsPbX3(Cl, Br, I) perovskite quantum dot glass has been widely reported, and the discovery of next-generation perovskite luminescent materials has been challenged by doping rare earth activators with energy-level transitions. In this work, we report a novel Eu-doped quantum dot glass material with tunable luminescence properties. The structure characteristics and tunable luminescence mechanism were investigated by combining X-ray diffraction, X-ray photoelectric spectroscopy, excitation and emission spectra. It was found that Eu ions replaced the lattice of Pb in CsPbBr3 quantum dots and formed CsEuBr3 quantum dots, which resulted in a blue emission. Meanwhile, a green emission from CsPbBr3 quantum dots and a red emission originally from Eu3+ in the glass matrix can also be observed by controlling the heat treatment temperature. A light-emitting diode is designed based on the prepared Eu-doped quantum dot glass without doping any phosphors, and a warm light with CCT at 4075 K is obtained. The present work provides a new luminescence tunable design principle for europium-doped quantum dot glass materials and could inspire the future exploration of rare earth ion-doped quantum dot glass materials.

Potential Application of Perovskite Glass Material in Photocatalysis Field

Abstract: So far, the application of inorganic glass materials in the field of photocatalysis has not been explored. First, phase separation induced CsPbBr3 quantum dot glasses, as an unprecedented method, i...

Negative thermal quenching CsPbBr3 glass-ceramic based on intrinsic radiation and vacancy defect co-induced dual-emission

Abstract: Halide perovskite glass-ceramic has recently moved into the center of the attention of perovskite research due to their potential for temperature sensing. However, quantum dots glass-ceramic with excellent luminescence performance still needs to be combined with rare-earth (RE) ions to accurately measure temperature. In this work, a novel non-RE doped dual-emission (460 nm and 512 nm) CsPbBr3 quantum dots was obtained in telluride glass via the friction crystallization method, where 512 nm was derived from intrinsic luminescence of quantum dots, and 460 nm was originated from thermally induced bromine vacancy, which can be used for temperature sensing. Fluorescence intensity ratio results indicate that the relative sensitivity of dual-emission could reach 5.6 % K−1 at 323 K. The discovery of non-RE doped CsPbBr3 QDs glass-ceramic with negative thermal quenching uncovers a new optional sensing glass material that surpass traditional RE-doped QDs glass by their tunability and sensitivity.

Highly Resolved and Robust Dynamic X-Ray Imaging Using Perovskite Glass-Ceramic Scintillator with Reduced Light Scattering.

Abstract: All-inorganic perovskite quantum dots (QDs) CsPbX3 (X = Cl, Br, and I) have recently emerged as a new promising class of X-ray scintillators. However, the instability of perovskite QDs and the strong optical scattering of the thick opaque QD scintillator film imped it to realize high-quality and robust X-ray image. Herein, the europium (Eu) doped CsPbBr3 QDs are in situ grown inside transparent amorphous matrix to form glass-ceramic (GC) scintillator with glass phase serving as both matrix and encapsulation for the perovskite QD scintillators. The small amount of Eu dopant optimizes the crystallization of CsPbBr3 QDs and makes their distribution more uniform in the glass matrix, which can significantly reduce the light scattering and also enhance the photoluminescence emission of CsPbBr3 QDs. As a result, a remarkably high spatial resolution of 15.0 lp mm-1 is realized thanks to the reduced light scattering, which is so far a record resolution for perovskite scintillator based X-ray imaging, and the scintillation stability is also significantly improved compared to the bare perovskite QD scintillators. Those results provide an effective platform particularly for the emerging perovskite nanocrystal scintillators to reduce light scattering and improve radiation hardness.

Luminescent ion-doped transparent glass ceramics for mid-infrared light sources [invited].

Abstract: Glass ceramics (GCs), which consist essentially of a homogeneous solid state dispersion of nanocrystals (NCs) embedded in a chemically inert and mechanically robust glass matrix, appear to be an extremely promising class of solid state materials that can be easily tailored into arbitrary shapes, including a new generation of optical fibers, for efficient incoherent and coherent sources of mid-infrared (MIR) light emission. This unique capability not only stems from the fact that one can tailor the underlying glass matrix for optimal macroscopic physical properties and ultrahigh transparency at the wavelengths of interest (resulting in appropriate “transparent glass ceramics” or TGCs), but also stems from the fact that one can embed these matrices with size and structure-tailored NCs, which in turn can be doped with relatively high concentrations of MIR emitting rare-earth or transition metal ions. This potential is tantamount to the localization of these highly efficient MIR ionic emitters into carefully selected and highly favorable “process-engineered” custom crystalline host “nanocages,” while insulating the ionic emitters from the emission-quenching glass host matrix, the latter being chosen largely because of its highly favorable macroscopic bulk properties, including its ductility and formability into near-arbitrary shapes (at appropriate temperatures). Such MIR TGCs appear to be very promising for numerous photonics applications, including compact and relatively efficient waveguide sensors, broadband incoherent MIR light sources, superluminescent light sources, advanced fiber-optic devices, and broadly wavelength-tunable and ultrashort pulse mode-locked fiber and bulk solid-state lasers. In this paper, we review past achievements in this field, starting with an overview of TGCs, followed by discussions of currently preferred methods of fabrication, characterization, and optimization of suitably doped oxyfluoride, tellurite, and chalcogenide TGCs and of our projections of anticipated future developments in this field at both the materials and device levels.

Potential Application of Perovskite Glass Material in Photocatalysis Field

Abstract: So far, the application of inorganic glass materials in the field of photocatalysis has not been explored. First, phase separation induced CsPbBr3 quantum dot glasses, as an unprecedented method, i...