Lorad is a world leader in the development and custom synthesis of inorganic sulfides for advanced technology applications.

SULFIDE SYNTHESES
Sulfides are manufactured at Lorad by a wide range of methods:

• Homogeneous Gas Phase reactions with volatile sulfur precursors:

TiCl₄ + H₂S → TiS₂ Titanium Disulfide, battery cathode material.Particularly useful for transition metal dichalcogenide synthesis; MS₂ , where M = Ta, Nb, Hf, Zr, Ti.

• Gas -Solid reactions:

H₂S+ La₂O₃ → La₂S₃, Lanthanum sulfide

H₂S + 2YCl₃ → Y₂S₃, Yttrium sulfide

CS₂+ MgO → MgS Magnesium sulfide

H₂S + CoSO₄ → Co₉S₈, Cobalt Sulfide, phase depends upon temperature Hydrodesulfurization catalyst

H₂S+ Ce₂(CO₃)₃ → Ce₂S₃ red pigment for plastic coloring

• Reactions with elemental sulfur:

Cd +S → CdS, Cadmium sulfide, photoconductor

Cu + xS → Cu_1.8S, Copper sulfide, glass colorant

• Solution Processes:

H₂S + Zn(aq) → ZnS(s) , Zinc sulfide, phosphor host lattice, source for closed system vapor transport crystal growth. High index optical coating material. IR window material.

Solvated Elemental Sulfur:

S_x(solv) + 2Cu(2+)aq → Cu₂S

• Homogeneous Precipitation:

(NH₂)₂CS + M⁽ⁿ⁺⁾(aq) → MnSx (ppt), Thiourea hydrolysis

CH₃CS.NH₂ + M⁽ⁿ⁺⁾(aq) → MnSx(ppt), Thioacetamide hydrolysis

All sulfides that can be precipitated by hydrogen sulfide can similarly be precipitated by the acid or base catalysed decomposition of organosulfur reagents. This process allows us to control particle size and distribution. In some cases, with dielectric constant modification and steric control agents, we can offer nanopowders and spherical monosized powders.

• Flux driven reactions:

S_x + Na₂CO₃ → Na₂Sx

Na₂Sx + Gd₂O₃ → Gd₂O₂S , phosphor host lattice, Tb, Eu activated

Classical method for manufacturing oxysulfide phosphors for cathode ray tubes, Scintillators, up-converters for security and tagging operations and, x-ray phosphors.

• Reduction Processes:

H₂ + CaSO₄ → CaS Component of CaGa₂S₄:Eu phosphors, suitable for LED Applications. Calcium and strontium thiogallates.

• Thermal decomposition of Dithiolato Complexes

In{(C₂H₅)₂NCS₂}₃ → In₂S₃, battery, quantum dots, photovoltaic thin film component.

Many dithiolato complexes are volatile and can therefore be employed as thin film chemical vapor deposition sources. Some dithiolato complexes can be employed as aerosols for thin film deposition. It is also possible to decompose appropriate dithiolato compounds in specific solvents to generate nano-particles (Quantum dots) of sulfides such as ZnS, CdS, In₂S₃.

Applications assistance for dithiolato CVD source materials is available.

• Non-Aqueous Solvent Routes with metal alkyls and Sulfur precursors:

Ga(C₂H₅)₃ + H₂S → Ga₂S₃, Gallium sulfide

Zn(C₂H₅)₂ + H₂S → ZnS, Zinc sulfide. Phosphor, can be doped with Mn or rare earths, Eu, Tb.

• Ceramic Method, ( High Temperature Solid State Synthesis):

CaS + La₂S₃ → CaLa₂S₄, calcium lanthanum sulfide, infrared window material

SrS + Ga₂S₃ → SrGa₂S₄, strontium gallium sulfide, excellent phosphor host lattice. Commercial quantities available as Eu activated phosphor for blue  to white LED conversion. A modified CaS.Eu red phosphor is also available in commercial quantities. These can be supplied with hydrophobic coatings.

CaS + Al₂S₃ → CaAl₂S₄, calcium aluminum sulfide, excellent green phosphor host.

• Sulfidized Sol-Gel Derived Precursors:

H₂S+ Dry Gel or low fired oxide → Sulfide. Has been used for titanium disulfide, (TiS₂ ) synthesis.

In addition to these general procedures, we have developed proprietary methods and modifications to manufacture specific sulfides (binary and multinary with specific additives to modify physical characteristics) for a variety of applications including batteries, luminescent materials for displays, data storage, radiation detection, and a variety of covert/security applications.

We select the most appropriate process to meet customer requirements, and fine tune these procedures, thereby enabling processes to be operated controllably to ensure appropriate purity, stoichiometry and particle size. Our manufacturing capacity for some specialty sulfides is currently in the range of multi-ton quantities.

It is important to stress that many items are custom synthesized and, for economic reasons, we may only be able to offer these with a 1-10kg minimum order quantity. We frequently work with our customers, (always on a strictly confidential basis) to develop new products, and seamlessly implement scale-up procedures to meet their production requirements.