Disclosed is a plurality of metal chalcogenide nanocrystals coated with multiple organic and inorganic ligands; wherein the metal is selected from Hg, Pb, Sn, Cd, Bi, Sb or a mixture thereof; and the chalcogen is selected from S, Se, Te or a mixture thereof; wherein the multiple inorganic ligands includes at least one inorganic ligands are selected from S.sup.2, HS.sup., Se.sup.2, Te.sup.2, OH.sup., BF.sub.4.sup., PF.sub.6.sup., Cl.sup., Br.sup., I.sup., As.sub.2Se.sub.3, Sb.sub.2S.sub.3, Sb.sub.2Te.sub.3, Sb.sub.2Se.sub.3, As.sub.2S.sub.3 or a mixture thereof; and wherein the absorption of the CH bonds of the organic ligands relative to the absorption of metal chalcogenide nanocrystals is lower than 50%, preferably lower than 20%.

A method of preparation of mercury chalcogenide nanoparticles that includes the steps of providing a precursor of mercury and mixing the precursor of mercury with a precursor of chalcogenide, wherein the precursor of mercury is a mercury thiolate. Also, mercury telluride nanoparticles and their use in an IR photodetector, an IR photoconversion device, an IR filter or an IR photodiode.

A method of preparation of mercury chalcogenide nanoparticles that includes the steps of providing a precursor of mercury and mixing the precursor of mercury with a precursor of chalcogenide, wherein the precursor of mercury is a mercury thiolate. Also, mercury telluride nanoparticles and their use in an IR photodetector, an IR photoconversion device, an IR filter or an IR photodiode.

Disclosed is a plurality of metal chalcogenide nanocrystals coated with multiple organic and inorganic ligands; wherein the metal is selected from Hg, Pb, Sn, Cd, Bi, Sb or a mixture thereof; and the chalcogen is selected from S, Se, Te or a mixture thereof; wherein the multiple inorganic ligands includes at least one inorganic ligands are selected from S.sup.2, HS.sup., Se.sup.2, Te.sup.2, OH.sup., BF.sub.4.sup., PF.sub.6.sup., Cl.sup., Br.sup., I.sup., As.sub.2Se.sub.3, Sb.sub.2S.sub.3, Sb.sub.2Te.sub.3, Sb.sub.2Se.sub.3, As.sub.2S.sub.3 or a mixture thereof; and wherein the absorption of the CH bonds of the organic ligands relative to the absorption of metal chalcogenide nanocrystals is lower than 50%, preferably lower than 20%.

Disclosed is a plurality of metal chalcogenide nanocrystals coated with multiple organic and inorganic ligands; wherein the metal is selected from Hg, Pb, Sn, Cd, Bi, Sb or a mixture thereof; and the chalcogen is selected from S, Se, Te or a mixture thereof; wherein the multiple inorganic ligands includes at least one inorganic ligands are selected from S.sup.2, HS.sup., Se.sup.2, Te.sup.2, OH.sup., BF.sub.4.sup., PF.sub.6.sup., Cl.sup., Br.sup., I.sup., As.sub.2Se.sub.3, Sb.sub.2S.sub.3, Sb.sub.2Te.sub.3, Sb.sub.2Se.sub.3, As.sub.2S.sub.3 or a mixture thereof; and wherein the absorption of the CH bonds of the organic ligands relative to the absorption of metal chalcogenide nanocrystals is lower than 50%, preferably lower than 20%.

A method of making a mercury based compound, a mercury based compound, and methods of using the mercury based compound and uses of the mercury based compound are disclosed. The mercury-based compound is in powder form and has the general chemical formula: M1.sub.aX.sub.b, where M1 is Hg, MxcMyd or a combination thereof, with Mx being Hg and My being an arbitrary element; wherein X is chloride, bromide, fluoride, iodide, sulphate nitrate or a combination thereof, wherein a, b, c and d are numbers between 0.1 and 10, wherein particles of the powder have a minimum average dimension of width of at least 50 nm and a maximum average dimension of width of at most 20 ?m, and wherein the mercury-based compound is paramagnetic and is present in an excited state.

A method of making a mercury based compound, a mercury based compound, and methods of using the mercury based compound and uses of the mercury based compound are disclosed. The mercury-based compound is in powder form and has the general chemical formula: M1.sub.aX.sub.b, where M1 is Hg, MxcMyd or a combination thereof, with Mx being Hg and My being an arbitrary element; wherein X is chloride, bromide, fluoride, iodide, sulphate nitrate or a combination thereof, wherein a, b, c and d are numbers between 0.1 and 10, wherein particles of the powder have a minimum average dimension of width of at least 50 nm and a maximum average dimension of width of at most 20 ?m, and wherein the mercury-based compound is paramagnetic and is present in an excited state.

The present discloser relates to an infrared device using intra-band electron transition of non-stoichiometric quantum dots and, more specifically, to non-stoichiometric quantum dot nanoparticles and an infrared device comprising the nanoparticles, in which the nanoparticles comprise quantum dot cores and nonthiol ligands bonded to the core and emits infrared rays from electron transition between discrete energy levels in the band. The infrared device has an effect of emitting infrared rays, particularly, mid-infrared rays or far-infrared rays, by using the electron transition between discrete energy levels in the band of quantum dots in which the proportion of a metal is higher than that of a chalcogen. In addition, the quantum dots are prepared by containing nonthiol ligands, and thus, compared with a conventional thiol ligand, ligand substitution is very easy while the n-type doping of quantum dots is maintained.

Many embodiments implement quantum confined nanoplatelets (NPLs) that can be induced to emit bright and tunable infrared emission from attached quantum dot (QD). Some embodiments provide mesoscale NPLs with a largest dimension of greater than 1 micron. Certain embodiments provide methods for growing mesoscale NPLs and QD on mesoscale NPLs heterostructures. Several embodiments provide near unity energy transfer from NPLs to QDs, which can quench NPL emission and emit with high quantum yield through the shortwave infrared. The QD defect emission can be kinetically tunable, enabling controlled mid-gap emission from NPLs.

Many embodiments implement quantum confined nanoplatelets (NPLs) that can be induced to emit bright and tunable infrared emission from attached quantum dot (QD). Some embodiments provide mesoscale NPLs with a largest dimension of greater than 1 micron. Certain embodiments provide methods for growing mesoscale NPLs and QD on mesoscale NPLs heterostructures. Several embodiments provide near unity energy transfer from NPLs to QDs, which can quench NPL emission and emit with high quantum yield through the shortwave infrared. The QD defect emission can be kinetically tunable, enabling controlled mid-gap emission from NPLs.