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Assembly of Microscopic Three-Dimensional Structures and Their Applications in Three-Dimensional Photonic Crystals
Published in Iniewski Krzysztof, Integrated Microsystems, 2017
Photonic crystals are often described as “semiconductors of light” because they can control the behavior of light. This capability originates from their fine structure, which has a length scale that is comparable to the wavelength of the target light. Commercially important wavelengths of light are the optical communication wavelengths of 1260–1625 nm. A photonic crystal operating in this region has fine structures of size 400–700 nm. To develop the equivalent of a semiconductor’s energy band gap—a photonic band gap—the ratio of the refractive index between a crystal’s material and its surroundings is expected to be larger than a certain value. In addition, the crystal’s material is expected to be transparent in the working wavelength range. Common semiconductor materials such as silicon (Si), gallium arsenide (GaAs) and indium phosphide (InP) can fulfill these requirements. Forming micrometer-scale patterns in these materials is easy using state-of-the-art semiconductor processing technologies, which are now used mainly for fabricating structures as narrow as several tens of nanometers on semiconductor wafers. However, because these technologies are developed for 2D processing, they cannot fabricate the 3D structures, which are crucial for full bandgap photonic crystals.
Quantum dot induced acute changes in lung mechanics are mouse strain dependent
Published in Inhalation Toxicology, 2018
David K. Scoville, Collin C. White, Dianne Botta, Dowon An, Zahra Afsharinejad, Theo K. Bammler, Xiaohu Gao, William A. Altemeier, Terrance J. Kavanagh
Quantum dots (QDs) are engineered semiconductor nanoparticles that are typically composed of either a cadmium/selenium (CdSe), Cd/tellurium (CdTe), or CdSeTe core that is surrounded by a zinc/sulfide (Zn/S) shell (Medintz et al., 2005). However, they can also be composed of other materials including PbS, indium phosphide, arsenic phosphide, silicon, germanium and carbon (diamond), the latter of which tend to be of lower toxicity than Cd-containing QDs (Lu et al., 2018). Additional outer coatings are frequently added for functionalization of QDs for a specific application (Azzazy et al., 2007; Michalet et al., 2005). Although we are not aware of any publicly available, peer-reviewed studies that have reported on Cd/Se QD exposures in the workplace, workers could be exposed in industrial settings because of inadequate containment during their manufacture or their incorporation into various products (e.g. ink-jet printing of solutions containing QDs, which can generate aerosols), or from accidental releases into the working environment.
Fluorescent quantum dots enable SARS-CoV-2 antiviral drug discovery and development
Published in Expert Opinion on Drug Discovery, 2022
Kirill Gorshkov, Kimihiro Susumu, Mason Wolak, Eunkeu Oh
Additionally, while Cd-based QDs are the brightest and have a wide range of emissions, Cd metal toxicity limits their application. This can be overcome with the development of bright and stable indium phosphide- or silicon-based QDs. Other types of nanoparticles (polymer, liposome, other metal NPs) with dye labeling would be alternatives, but these have size limitations or additional complexity associated with dye conjugation.