The present invention relates to the field of luminescent crystals (LCs), and more specifically to Quantum Dots (QDs) of formula M.sup.1.sub.aM.sup.2.sub.bX.sub.c, wherein the substituents are as defined in the specification. The invention provides methods of manufacturing such luminescent crystals, particularly by dispersing suitable starting materials in the presence of a liquid and by the aid of milling balls; to compositions comprising luminescent crystals and to electronic devices, decorative coatings; and to intermediates comprising luminescent crystals.

Embodiments of the present disclosure provide for passivated quantum dots, methods of making passivated quantum dots, methods of using passivated quantum dots, and the like.

A light valve containing ABX.sub.3 perovskite particles (200) suspended in a liquid suspension (300) that can control light transmittance is provided. The preferable ABX.sub.3 perovskite particles (200) are halide ABX.sub.3 perovskite particles wherein A is at least one of Cs.sup.+, CH.sub.3NH.sub.3.sup.+, and Rb.sup.+, B is at least one of Pb.sup.2+, Ge.sup.2+, and Sn.sup.2+, and X is at least one of Cl.sup., Br.sup., and I.sup.. Use of the light valve in the manufacture of a light control device and a method of controlling light transmittance by using the light valve are also provided.

Disclosed herein is a polymeric film, the film comprising a polymeric matrix material, a plurality of perovskite nanocrystals and/or aggregates of perovskite nanocrystals dispersed throughout the polymeric matrix material. There is also disclosed a perovskite polymer resin composition, a perovskite-polymer resin composition, a perovskite ink and a method of forming a luminescent film using any one of the compositions or ink. Preferably, the perovskite material is a lead halide perovskite containing a cation selected from Cs, an alkylammonium ion, or a formamidinium ion. The polymeric matrix is preferably formed from monomers comprising a vinyl or an acrylate group.

A light valve containing ABX.sub.3 perovskite particles (200) suspended in a liquid suspension (300) that can control light transmittance is provided. The preferable ABX.sub.3 perovskite particles (200) are halide ABX.sub.3 perovskite particles wherein A is at least one of Cs.sup.+, CH.sub.3NH.sub.3.sup.+, and Rb.sup.+, B is at least one of Pb.sup.2+, Ge.sup.2+, and Sn.sup.2+, and X is at least one of Cl.sup., Br.sup., and I.sup.. Use of the light valve in the manufacture of a light control device and a method of controlling light transmittance by using the light valve are also provided.

A perovskite quantum dot preparation method and a perovskite quantum dot solution are provided. The preparation method may include: providing a first solution including caesium oleate, a second solution including lead halide and a third solution including DDAB; adding the first solution, the second solution and the third solution into a non-polar alkyl solution at a preset proportion and stirring to obtain a perovskite quantum dot solution; the perovskite quantum dot solution may include caesium-lead-halogen of pure phase. In this way, the present disclosure can easily obtain the perovskite quantum dot solution including caesium-lead-halogen of pure phase.

A main object of the present disclosure is to provide a novel cathode active material that may be used for a fluoride ion battery. The present disclosure achieves the object by providing a cathode active material used for a fluoride ion battery, comprising a composition represented by Pb.sub.2xCu.sub.1+xF.sub.6, wherein 0x<2.

Present invention provides a process for the synthesis of size and composition tunable colloidal PbMgS core and PbMgS/MS core shell quantum dots emitting in the near infrared (NIR) region of the spectrum in a single operation in a continuous flow reactor. M includes at least one of Cd, Mg, Zn and Cu metals.

A perovskite luminescent nanocrystal has a chemical formula represented by: Cs.sub.4BX.sub.6, wherein B includes one or more selected from the group consisting of Ge, Pb, Sn, Sb, Bi, Cu, and Mn, and X includes one or more selected from the group consisting of Cl, Br, and I, wherein the Cs.sub.4BX.sub.6 perovskite luminescent nanocrystal has a pure phase, and a molar ratio of Cs to B (Cs/B) in the Cs.sub.4BX.sub.6 perovskite luminescent nanocrystal is greater than 1 and less than 4.

Bandgap-tunable perovskite compositions are provided having the formula CsPb(A.sub.xB.sub.y).sub.3, wherein A and B are each a halogen. The mixed halide perovskite composition has a morphology which suppresses phase segregation to stabilize a tuned bandgap of the mixed halide perovskite composition. For example, the perovskite may be in the form of nanocrystals embedded in a non-perovskite matrix, which, for example, may have the formula Cs.sub.4Pb(A.sub.xB.sub.y).sub.6, wherein A and B are each a halogen. Solar cells and light-emitting diodes comprising the mixed perovskite compositions are also provided.