A quantum dot including zinc, tellurium, selenium, and sulfur, wherein the quantum dot comprises a core and a shell disposed on the core, and wherein the quantum dot is a cadmium-free red light-emitting quantum dot and has an emission peak wavelength of greater than or equal to about 600 nanometers (nm), and efficiency of greater than or equal to about 50%.

A process for the synthesis of transition metal chalcogenides (TMC) having formula (I). More particularly, the present work relates to a one pot single phase process for the synthesis of a TMC system having formula (I) by wet chemistry. Formula (I) is represented as A.sub.x-B.sub.y.

The present invention relates to an orthogonal-phase compound and its nonlinear optical (NLO) crystal of BaGa.sub.7Se.sub.7, its producing method and uses thereof. Polycrystalline orthogonal-phase BaGa.sub.4Se.sub.7 was prepared by a high-temperature solid-phase reaction in a sealed silica tube. Large size single crystals of orthogonal-phase BaGa.sub.4Se.sub.7 could be prepared by the flux method or Bridgman method. BaGa.sub.4Se.sub.7 crystallizes in the point group mm2. Orthogonal-phase BaGa.sub.4Se.sub.7 has a powder second harmonic generation (SHG) efficiency of about 5 times that of AgGaS.sub.2 and is phase-matchable. The orthogonal-phase BaGa.sub.4Se.sub.7 is non-hygroscopic and has good mechanical properties, which makes it easy to cut, polish, and coat by normal processing. The orthogonal-phase BaGa.sub.4Se.sub.7 crystal has never been cracked during cutting and polishing. The orthogonal-phase compound and NLO crystal of BaGa.sub.4Se.sub.7 can be used as NLO devices.

A bacterially induced crystal particle is formed by a composite shell that encloses a hollow space. The composite shell layer includes a biomaterial and a metallic material. The biomaterial includes cell wall or cell membrane of a bacterium. The metallic material includes oxides, sulfides, selenides, acid salt compounds of a transition metal, or any combination thereof. When the bacterially induced crystal particle is spheric, the composite shell is formed by two dome-shaped portions, and a thickness of each of the dome-shaped portions is not less than 1/73 of a diameter of the bacterially induced crystal particle. Alternatively, when the bacterially induced crystal particle is rod-shaped, the thickness of the dome-shaped portions is not less than 1/73 of a width of the bacterially induced crystal particle, and a thickness of the cylindrical portion is not less than 1/37 of the width of the bacterially induced crystal particle.

A color filter including a first layer including first quantum dots and a second layer including second quantum dots that are different from the first quantum dots, and disposed on the first layer, wherein a quantum yield of the first quantum dots is greater than a quantum yield of the second quantum dots, and wherein an absorption of blue light of the second quantum dots is greater than an absorption of the blue light of the first quantum dots.

The present invention provides the use of a lead (IV) containing compound to prepare a lead chalcogenide nanocrystal and a method for producing broadband lead chalcogenide nanocrystals in a low cost, size-controllable and scalable method, the method comprising contacting a lead (IV) containing compound with an organic acid and a chalcogen-containing reagent.

A method of producing nanoparticles comprises effecting conversion of a molecular cluster compound to the material of the nanoparticles. The molecular cluster compound comprises a first ion and a second ion to be incorporated into the growing nanoparticles. The conversion can be effected in the presence of a second molecular cluster compound comprising a third ion and a fourth ion to be incorporated into the growing nanoparticles, under conditions permitting seeding and growth of the nanoparticles via consumption of a first molecular cluster compound.

A quantum dot including a nanoparticle template including a first semiconductor nanocrystal including a Group II-VI compound, a quantum well including a second semiconductor nanocrystal disposed on the nanoparticle template, the second semiconductor nanocrystal including a Group IIIA metal excluding aluminum and a Group V element; and a shell comprising a third semiconductor nanocrystal disposed on the quantum well, the third semiconductor nanocrystal including a Group II-VI compound, wherein the quantum dot does not include cadmium, a band gap energy of the second semiconductor nanocrystal is less than a band gap energy of the first semiconductor nanocrystal, the band gap energy of the second semiconductor nanocrystal is less than a band gap energy of the third semiconductor nanocrystal, and the quantum dot includes an additional metal including an alkali metal, an alkaline earth metal, aluminum, iron, cobalt, nickel, copper, zinc, or a combination thereof.

Methods for making of nanomaterials from a bulk source material involve heating the material in an inert atmosphere, whereby a material having at least one nanometer scale dimension is formed on a nearby substrate surface. The heated bulk source material forms a vapor phase which is deposited in the form of the nanomaterial on a growth surface of the substrate. The methods require no complex machinery or devices, unlike chemical vapor deposition, and can be tuned to provide different forms of nanomaterials, such as two-dimensional or other crystalline forms. The methods can be used to make two-dimensional semiconductor materials and semiconductor devices.

Methods for purifying reaction precursors used in the synthesis of inorganic compounds and methods for synthesizing inorganic compounds from the purified precursors are provided. Also provided are methods for purifying the inorganic compounds and methods for crystallizing the inorganic compounds from a melt. γ and X-ray detectors incorporating the crystals of the inorganic compounds are also provided.