05.29.17
Quantum dots are extremely tiny man-made nanoparticles typically between 10 to 10000 atoms (1 to 10 nanometers) in diameter, which is smaller than 1/10000 th the width of a human hair. However, the effects of this extreme small size cannot be ignored. Quantum dots are actually very powerful materials, and it is their size that gives them unique abilities, including converting light to nearly any color in the visible spectrum with very high efficiency.
The electronic characteristics of quantum dots are determined by quantum confinement effect depending on their chemical composition, size and shape. This means that we can control the color of light given off by a quantum dot just by changing its size. Bigger dots emit longer wavelengths, such as red, while smaller dots emit shorter wavelengths, such as green or blue.
The tune of a quantum dot is the wavelength of light that it emits. These unique properties of quantum dot can be utilized for solar cells, TV displays, smartphones, stable displays, security tags, security inks, sensors and more.
Various types of quantum dots currently exist, but in general, quantum dots are made of semiconductor materials such as CdSe, CdS, InP, ZnS, InP/ZnS, CuInS2, CuInSe2(CIS:copper indium selenide or sulfide), AgS, and PbS etc. However, these materials are relatively expensive and toxic, especially Cd, Se and Pb. These toxic heavy metals are unfavorable and occasionally prohibited for use in many industrial areas. Therefore, it is essential to develop toxic metal-free quantum dots, which exhibit a high light emitting quantum efficiency and stability as good as those of the expensive and toxic metal-based quantum dots.
In this regard, Dr. Ryohei Mori at Fuji Pigment Co., Ltd has been researching and developing inexpensive quantum dots based on safe materials, and has succeeded in developing a large-scale manufacturing process for silicon quantum dots.
Dr. Mori has been already established the large scale production process for carbon quantum dot and graphene quantum dot, which are also environmentally friendly materials. Quantum yield exceeds 30%, and Dr. Mori is still pursuing higher quantum efficiency.
The electronic characteristics of quantum dots are determined by quantum confinement effect depending on their chemical composition, size and shape. This means that we can control the color of light given off by a quantum dot just by changing its size. Bigger dots emit longer wavelengths, such as red, while smaller dots emit shorter wavelengths, such as green or blue.
The tune of a quantum dot is the wavelength of light that it emits. These unique properties of quantum dot can be utilized for solar cells, TV displays, smartphones, stable displays, security tags, security inks, sensors and more.
Various types of quantum dots currently exist, but in general, quantum dots are made of semiconductor materials such as CdSe, CdS, InP, ZnS, InP/ZnS, CuInS2, CuInSe2(CIS:copper indium selenide or sulfide), AgS, and PbS etc. However, these materials are relatively expensive and toxic, especially Cd, Se and Pb. These toxic heavy metals are unfavorable and occasionally prohibited for use in many industrial areas. Therefore, it is essential to develop toxic metal-free quantum dots, which exhibit a high light emitting quantum efficiency and stability as good as those of the expensive and toxic metal-based quantum dots.
In this regard, Dr. Ryohei Mori at Fuji Pigment Co., Ltd has been researching and developing inexpensive quantum dots based on safe materials, and has succeeded in developing a large-scale manufacturing process for silicon quantum dots.
Dr. Mori has been already established the large scale production process for carbon quantum dot and graphene quantum dot, which are also environmentally friendly materials. Quantum yield exceeds 30%, and Dr. Mori is still pursuing higher quantum efficiency.
