Perovskite quantum dots under UV light. Source: Fuji PigmentFuji Pigment Co., Ltd is developing a new type of quantum dots using perovskite, claiming to be the first company in the world to commercialize perovskite quantum dots.

The chemical composition of perovskite quantum dots is either CsPbX3 or CH3NH3PbX3 (X= Cl, Br, I) with a quantum efficiency of 50% to 80% and a half-width of 15nm to 39nm. This tiny size of the dots allows them to be used in displays, lasers, light emitting diodes (LEDs) and bio-imaging.

Fuji Pigment is researching a way to coat the perovskite quantum dot surface with either polymer or inorganic materials to enhance its resistance against water, light and heat.

If this is achieved, the quantum dots could be used for numerous applications including TV displays and smartphone displays, solar cells, security tags, security inks, sensors, quantum dot lasers, quantum dot transistors, photonic crystals, bio-imaging, biomarkers, solid-material-based memory, thermoelectric materials, quantum dot computers, artificial photosynthesis and light emitting diodes (LEDs).

Quantum dots are extremely tiny nanoparticles typically between 10 to 10,000 atoms in diameter, or about 1nm to 9nm, which is smaller than a human hair. These dots are so small they cannot be seen under a conventional microscope. Despite their size, quantum dots are very powerful materials with highly efficient conversion of light to nearly any color in the visible spectrum making them advantageous for numerous applications.

Various types of quantum dots currently exist and are generally made of semiconductor materials such as cadmium, indium and zinc. However, cadmium is toxic while indium is expensive and requires complete exclusion of O2 and H20 to synthesize the material for use in quantum dots. Perovskite offers a cheap, non-toxic alternative, opening up the technology to new opportunities for use, Fuji Pigment says.