Improving the Quality and Luminescence Performance of All-Inorganic Perovskite Nanomaterials for Light-Emitting Devices by Surface Engineering.

Lead halide perovskites and their applications in the optoelectronic field have garnered intensive interest over the years. Inorganic perovskites (IHP), though a novel class of material, are considered as one of the most promising optoelectronic materials. These materials are widely used in detectors, solar cells, and other devices, owing to their excellent charge-transport properties, high defect tolerance, composition- and size-dependent luminescence, narrow emission, and high photoluminescence quantum yield.

The luminescence properties of CsPbMBr perovskite nanocrystals transformed from CsPbBr mediated by various divalent bromide MBr salts.

A novel high concentration doping method based on the transformation from CsPbBr nanocrystals (NCs), which reacted with divalent metal bromide MBr, to CsPbMBr NCs was developed. Two types of M and Zn which cannot emit light and Mn and Eu which can be used as the luminous centres, were chosen to trigger the transformation of CsPbBr NCs to CsPbMBr NCs. CsPbZnBr NCs maintained high photoluminescence quantum yields (PLQY) (>75%) and had good dispersion in hexane without obvious dissolution or agglomeration after two weeks.

Broadening emission band of BaBO: Dy by codoping Ce as sensitizer and its application to white LEDs.

In order to achieve broad-band white emitting phosphor, Ce/Dy codoped BaBO were synthesized by a solid-state method, and the luminescence property and energy transfer were discussed in detail. Dy doped BaBO shows white emission, and the two narrow peaks which are assigned to the F→H and F→H transitions of Dy ions, respectively. When codoped Ce as sensitizer, the broad-band white emission can be obtained by the energy transfer from Ce to Dy ions in BaBO, and the mechanism is the dipole-dipole interaction.

Inducing tunable host luminescence in ZnGeO tetrahedral materials via doping Cr.

ZnGeO consisting of tetrahedron, and it is a self-luminescent material due to the presence of the native defects and shows a bluish white emission excited by ultraviolet. Although Cr doped in a tetrahedron generally cannot show luminescence, in this research, new defects are formed as Cr doped in ZnGeO, hence a green emission band can be obtained. Meanwhile, the intensity of host emission is also decreased.

A novel red emitting phosphor LiBaB O :Sm /Sm , li with broad excitation band for white LEDs.

A novel tunable red emitting phosphor LiBaB O :Sm /Sm , Li with broad excitation band was synthesized by a high temperature solid-state method. Luminescence properties were investigated in detail by luminescence, X-ray photoelectron spectroscopy (XPS) spectra and CIE chromaticity coordinates. XPS data confirmed that there were Sm in LiBaB O :Sm and Sm /Sm in LiBaB O :Sm /Sm , respectively.

Coexistence phenomenon of Ce-Ce and Eu-Eu in Ce/Eu co-doped LiBaBO phosphor: luminescence and energy transfer.

Ce/Eu-doped LiBaBO (LBB) samples were prepared via conventional high temperature solid state reactions. The XRD patterns, crystal structures, luminescence properties, and decay times were investigated systematically. Ce ions exist in LBB:xCe that were synthesized in a reducing atmosphere and in an air atmosphere.

Substituting Different Cations in Tuning of the Photoluminescence in Ba3Ce(PO4)3.

An attempt has been made to explore how the luminescence properties change when rare-earth elements are substituted for different cations in the host. We synthesized Eu(2+)-doped Ba3Ce(PO4)3 via a high-temperature solid-state reaction process, substituting for Ba(2+) and Ce(3+) ions and naming them Ba3Ce(1-x)(PO4)3:xEu(2+) and Ba(3-y)Ce(PO4)3:yEu(2+), respectively. The structure, X-ray diffraction with Rietveld refinements, reflectance spectra, and luminescence characterization of the phosphor are measured to explore the difference of substituting for different ions.

Structure, luminescence properties and energy transfer of Tb(3+)-Eu(3+) codoped LiBaB9O15 phosphors.

A series of single-composition phosphors LiBaB9O15:Tb(3+),Eu(3+) have been prepared via a high-temperature solid-state reaction process. The structure and luminescence properties of phosphors are described. The LiBaB9O15:Tb(3+) phosphor shows a characteristic green emission, with the peak located at 551 nm, which corresponds to the (5)D4→(7)F5 transition of Tb(3+).