Rare Specialty Metals & Chemical Products

Rare Specialty Metals & Chemical Products are becoming increasingly critical in today’s rapidly advancing technologies in optics, photovoltaics (PV), semiconductors, thermoelectric coolers (TEC), metallurgy, agriculture and industrial products. By understanding the physical and chemical properties of these materials and developing novel technologies for their recovery and processing from complex raw materials, II-VI continues to bring excellent value to its customers and markets and is amongst the world’s foremost Rare Specialty Metals & Chemical Products. Our product development and manufacturing teams include expert metallurgists, chemists and engineers, supported by an extensive infrastructure of state-of-the-art analytical instrumentation and automated manufacturing controls and systems.

Common Applications of Selenium

  • Glass and Ceramics: Selenium is used extensively in glass and ceramic manufacturing, where it is used to impart red-bronze color to glasses, enamels and glazes as well as to remove color from glass by counteracting the green tint imparted by ferrous impurities.
  • Catalysts: Selenium is a catalyst in many chemical reactions and is widely used in various industrial and laboratory syntheses, particularly organoselenium chemistry. It is also widely used in structure determination of proteins and nucleic acids by X-ray crystallography.
  • Metallurgical Applications: Selenium is used with bismuth in brasses to reduce the toxicity of lead.
  • Rubber Industry: Selenium can improve the abrasion resistance (wear properties) of vulcanized rubber.
  • Electronics: due to its photoconductive properties, Selenium is used in photocopying, photocells, x-ray imaging, light meters and photovoltaic solar cells.
  • Photography: Selenium is used as a toner in photographic prints.
  • Medical: Selenium disulfide is used as an active ingredient in some dandruff shampoos, and in body lotions as an anti-fungal aid.
  • Nutrition: Selenium is used widely in multi-vitamins and dietary supplements (typically 50 to 200 micrograms per day for adult humans). The role of Selenium in preventing various types of cancer is being widely studied and reported; Selenium is also being studied as a key additive in anti-HIV drugs.
  • Livestock feeds: Selenium is used in carefully prescribed quantities to improve the nutritional value of animal feeds.
  • Cosmetics: an evolving application for Selenium includes orthodontic materials with improved antibacterial properties.
  • Coatings: Selenium is used as an antimicrobial/antifouling additive in industrial, architectural and marine coatings and sealants.
  • Agriculture and Animal Nutrition: Selenium is an essential micronutrient for animals and humans. Numerous studies of Micronutrient deficiencies in Soils and Crops across the world have been reported over the years. This problem is especially critical to the nutrition of people, and animals alike, in the developing world. Studies correlating the prevalence of many common diseases to Selenium deficiency in the local populations have been widely publicized in recent years. Systematic and controlled Selenium Supplementation is now being carried out in several countries by adding inorganic selenium (Sodium Selanate) to fertilizers. In the soil, Selenium is rapidly reduced to an insoluble form and therefore, the risk of leaching Selenium into the environment is considered negligible. Selenium in the form of Sodium Selenate is taken up by plants from the soil when added to the fertilizer. This sodium salt, Na2SeO4 contains 41% Selenium. II-VI is the world’s leading producer of high quality Sodium Selanate and has been supplying this essential ingredient reliably for two decades. II-VI’s Sodium Selanate is also compounded into several commercial Pet and Poultry Nutritional Products and Supplements.
  • Photovoltaics: Copper Indium Gallium DiSelenide (CIGS) Photovoltaics
    Being a direct bandgap material, Selenium-containing CIGS also has very strong light absorption characteristics. Only 1-2 microns of CIGS is enough to absorb most sunlight. A much greater thickness of crystalline silicon is required for the same absorption. Due to these ideal optical properties, CIGS is therefore another critical material in the category of thin film solar cells, along with CdTe. CIGS films can be manufactured by several different methods. The most common vacuum-based process co-evaporates or co-sputters copper, gallium, and indium, then anneals the resulting film with a selenide vapor to form the final CIGS structure. An alternate vacuum method directly co-evaporates copper, gallium, indium and selenium onto a heated substrate. Non-vacuum-based alternative processes that are also being considered include the deposition of nanoparticles of the precursor materials on the substrate and then sintering them in situ. More recently, electroplating has emerged as another low cost alternative for CIGS. II-VI’s high purity Solar Grade Selenium is setting the standard for qualification by numerous CIGS Solar panel producers across the world. Our material is used across the spectrum of CIGS technologies.

Common Applications of Tellurium

After a long incubation period, the CdTe segment of the Solar Industry has finally come of age. With a band gap of 1.5 eV, Tellurium-containing Cadmium Telluride (CdTe) is perfectly matched to the distribution of photons in the solar spectrum in terms of conversion to electricity. II-VI is uniquely positioned as the ideal Tellurium partner for this critical technology through its breadth of technologies, capacity and experience.
 
II-VI’s Tellurium is used in manufacturing the CdTe utilized by the World’s leading solar panel producers. This “Solar Grade” material is processed through our state-of-the-art manufacturing module in a tightly controlled environment. Skilled engineers from our Quality Department diligently monitor the quality of each batch of material produced, prior to its shipment to the customer.
 
Leading CdTe Photovoltaic panel producers have brought down their production costs well below $1/W, making Solar Energy an affordable solution for generations to come. II-VI is proud to be a major contributor to this growth in Green Energy through its global leadership in Tellurium production.
 
 

Products

Applications

Te

Tellurium High Purity Tellurium Metal and Tellurium Dioxide

Se

Selenium High Purity Selenium Metal

Li

Lithium Lithium Chemicals, industrial and battery grade

Sc

Scandium Scandium Oxide and Scandium Alloys

SeO2

Selenium Dioxide Photovoltaic Solar Cells, Laser Optics

Na2SeO3

Sodium Selenite Glass Colorant, Decolorant, Animal Feed Additive

Na2SeO4

Sodium Selenate

Agricultural Grade: Fertilizer Application, Animal Feed Additive
Drench Grade: Pharmaceutical Applications

BaSeO4

Barium Selenate Fertilizer Application

ZnSeO3

Zinc Selenite Glass Industry

 

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