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.

The present specification relates to an ink composition including: a compound represented by Formula 1; and a solvent represented by the Formula 2, and a method for manufacturing an organic light emitting device formed by using the ink composition.

The present specification relates to an ink composition including: a compound represented by Formula 1; and a solvent represented by the Formula 2, and a method for manufacturing an organic light emitting device formed by using the ink composition.

Reverse photochromic ink formulations containing encapsulated reverse photochromic colorant, methods of erasing reverse photochromic ink formulations including encapsulated reverse photochromic colorants by exposing them to UV light, and writing instruments including a writing tip portion connected to a light-shielding tubular member or refill and a reverse photochromic ink formulation including encapsulated reverse photochromic colorant are provided herein.

Reverse photochromic ink formulations containing encapsulated reverse photochromic colorant, methods of erasing reverse photochromic ink formulations including encapsulated reverse photochromic colorants by exposing them to UV light, and writing instruments including a writing tip portion connected to a light-shielding tubular member or refill and a reverse photochromic ink formulation including encapsulated reverse photochromic colorant are provided herein.

Reverse photochromic ink formulations containing at least one reverse photochromic colorant, methods of erasing reverse photochromic ink formulations by exposing them to UV light, and writing instruments including a writing tip portion connected to a light-shielding tubular member or refill and a reverse photochromic ink formulation are provided herein.

Reverse photochromic ink formulations containing at least one reverse photochromic colorant, methods of erasing reverse photochromic ink formulations by exposing them to UV light, and writing instruments including a writing tip portion connected to a light-shielding tubular member or refill and a reverse photochromic ink formulation are provided herein.

A marking composition may include an aqueous carrier and thermochromic capsules. The thermochromic capsules may include a leuco dye, an activator, and a temperature regulator. The thermochromic capsules may have a volume average size effective to resist temperature-mediated discoloration at a temperature of at least up to 40° C. by dissipating heat. In some embodiments, the marking composition marks a substrate with a substantially erasable mark, for example, in response to frictional contact with an eraser.

A marking composition may include an aqueous carrier and thermochromic capsules. The thermochromic capsules may include a leuco dye, an activator, and a temperature regulator. The thermochromic capsules may have a volume average size effective to resist temperature-mediated discoloration at a temperature of at least up to 40° C. by dissipating heat. In some embodiments, the marking composition marks a substrate with a substantially erasable mark, for example, in response to frictional contact with an eraser.

An organic long-persistent luminescent composition containing a first organic compound, a second organic compound and a third organic compound and satisfying the following expression (1) is a long-persistent luminescent material that facilitates emission color control. E.sub.S1(A) represents a lowest excited singlet energy level of emission from the first organic compound and the second organic compound, E.sub.S1(B) represents a lowest excited singlet energy level of the third organic compound.
E.sub.S1(B)−E.sub.S1(A)≤0.15 eV  (1)