A scintillator is a material that exhibits scintillation, the property of luminescence, when excited by ionizing radiation. Luminescent materials, when struck by an incoming particle, absorb its energy and scintillate. Sometimes, the excited state is metastable, so the relaxation back down from the excited state to lower states is delayed. The process then corresponds to one of two phenomena: delayed fluorescence or phosphorescence. The correspondence depends on the type of transition and hence the wavelength of the emitted optical photon.
Caesium iodide or cesium iodide is the ionic compound of caesium and iodine. It is often used as the input phosphor of an X-ray image intensifier tube found in fluoroscopy equipment. Caesium iodide photocathodes are highly efficient at extreme ultraviolet wavelengths.
Cadmium telluride (CdTe) is a stable crystalline compound formed from cadmium and tellurium. It is mainly used as the semiconducting material in cadmium telluride photovoltaics and an infrared optical window. It is usually sandwiched with cadmium sulfide to form a p–n junction solar PV cell.
Gallium(III) bromide (GaBr3) is a chemical compound, and one of four gallium trihalides.
The thallium halides include monohalides, where thallium has oxidation state +1, trihalides in which thallium generally has oxidation state +3, and some intermediate halides containing thallium with mixed +1 and +3 oxidation states. These salts find use in specialized optical settings, such as focusing elements in research spectrophotometers. Compared to the more common zinc selenide-based optics, materials such as thallium bromoiodide enable transmission at longer wavelengths. In the infrared, this allows for measurements as low as 350 cm−1 (28 μm), whereas zinc selenide is opaque by 21.5 μm, and ZnSe optics are generally only usable to 650 cm−1 (15 μm).
There are three sets of Indium halides, the trihalides, the monohalides, and several intermediate halides. In the monohalides the oxidation state of indium is +1 and their proper names are indium(I) fluoride, indium(I) chloride, indium(I) bromide and indium(I) iodide.
Caesium cadmium chloride (CsCdCl3) is a synthetic crystalline material. It belongs to the AMX3 group (where A=alkali metal, M=bivalent metal, X=halogen ions). It crystallizes in a hexagonal space group P63/mmc with unit cell lengths a = 7.403 Å and c = 18.406 Å, with one cadmium ion having D3d symmetry and the other having C3v symmetry.
Tin(IV) bromide is the chemical compound SnBr4. It is a colourless low melting solid.
Photon upconversion (UC) is a process in which the sequential absorption of two or more photons leads to the emission of light at shorter wavelength than the excitation wavelength. It is an anti-Stokes type emission. An example is the conversion of infrared light to visible light. Upconversion can take place in both organic and inorganic materials, through a number of different mechanisms. Organic molecules that can achieve photon upconversion through triplet-triplet annihilation are typically polycyclic aromatic hydrocarbons (PAHs). Inorganic materials capable of photon upconversion often contain ions of d-block or f-block elements. Examples of these ions are Ln3+, Ti2+, Ni2+, Mo3+, Re4+, Os4+, and so on.
Titanium(III) bromide is the inorganic compound with the formula TiBr3. It is a blue black paramagnetic solid with a reddish reflection. It has few applications, although it is a catalyst for the polymerization of alkenes.
Lead bismuthate is a chemical compound with the formula Pb(BiO3)2. has only been discovered in recent years in the laboratory as it is not naturally occurring. Lead bismuthate forms a pentavalent structure, significantly different from the regular ionic interactions of sodium bismuthate, but similar to that of strontium bismuthate. In the structure, six oxygen atoms are coordinated octahedrally to both the bismuth and lead atoms. The bismuth and oxygen atoms form negatively charged layers by creating repeating octahedral geometries. The positively charged lead atoms are then disbursed within the layers, forming a hexagonal unit cell, with a lead atom in each of the corners. The density of the crystal is 9.18 g/cm3. The formula weight is 233.99 g/mol. The volume of the crystal structure unit is 169.26 A3. Lattice parameters (a) is 5.321 angstroms.
Upconverting nanoparticles (UCNPs) are nanoscale particles that exhibit photon upconversion. In photon upconversion, two or more incident photons of relatively low energy are absorbed and converted into one emitted photon with higher energy. Generally, absorption occurs in the infrared, while emission occurs in the visible or ultraviolet regions of the electromagnetic spectrum. UCNPs are usually composed of rare-earth based lanthanide- or actinide-doped transition metals and are of particular interest for their applications in in vivo bio-imaging, bio-sensing, and nanomedicine because of their highly efficient cellular uptake and high optical penetrating power with little background noise in the deep tissue level. They also have potential applications in photovoltaics and security, such as infrared detection of hazardous materials.
A carbonate fluoride, fluoride carbonate, fluorocarbonate or fluocarbonate is a double salt containing both carbonate and fluoride. The salts are usually insoluble in water, and can have more than one kind of metal cation to make more complex compounds. Rare-earth fluorocarbonates are particularly important as ore minerals for the light rare-earth elements lanthanum, cerium and neodymium. Bastnäsite is the most important source of these elements. Other artificial compounds are under investigation as non-linear optical materials and for transparency in the ultraviolet, with effects over a dozen times greater than Potassium dideuterium phosphate.
Perovskite nanocrystals are a class of semiconductor nanocrystals, which exhibit unique characteristics that separate them from traditional quantum dots. Perovskite nanocrystals have an ABX3 composition where A = cesium, methylammonium (MA), or formamidinium (FA); B = lead or tin; and X = chloride, bromide, or iodide.
Titanium(II) bromide is the inorganic compound with the formula TiBr2. It is a black micaceous solid. It adopts the cadmium iodide structure, featuring octahedral Ti(II) centers. It arises via the reaction of the elements:
Selenogallates are chemical compounds which contain anionic units of selenium connected to gallium. They can be considered as gallates where selenium substitutes for oxygen. Similar compounds include the thiogallates and selenostannates. They are in the category of chalcogenotrielates or more broadly chalcogenometallates.
Phosphide bromides or bromide phosphides are compounds containing anions composed of bromide (Br−) and phosphide (P3−) anions. Usually phosphorus is covalently connected into more complex structures. They can be considered as mixed anion compounds. They are in the category of pnictidehalides. Related compounds include the phosphide chlorides, phosphide iodides, nitride bromides, arsenide bromides, and antimonide bromides.
Arsenide bromides or bromide arsenides are compounds containing anions composed of bromide (Br−) and arsenide (As3−). They can be considered as mixed anion compounds. They are in the category of pnictidehalides. Related compounds include the arsenide chlorides, arsenide iodides, phosphide bromides, and antimonide bromides.
Zirconium(III) bromide is an inorganic compound with the formula ZrBr3.
