Methods and devices that use alkali metal chalcohalides having the chemical formula A.sub.2TeX.sub.6, wherein A is Cs or Rb and X is I or Br, to convert hard radiation, such as X-rays, gamma-rays, and/or alpha-particles, into an electric signal are provided. The devices include optoelectronic and photonic devices, such as photodetectors and photodiodes. The method includes exposing the alkali metal chalcohalide material to incident radiation, wherein the material absorbs the incident radiation and electron-hole pairs are generated in the material. A detector is configured to measure a signal generated by the electron-hole pairs that are formed when the material is exposed to incident radiation.

A conductive material including a first element selected from a transition metal, a platinum-group element, a rare earth element, and a combination thereof, a second element having an atomic radius which is 10 percent less than to 10 percent greater than an atomic radius of the first element, and a chalcogen element, wherein the conductive material has a layered crystal structure.

A quantum nanomaterial having a bandgap that may be tuned to enable the quantum nanomaterial to detect IR radiation in selected regions including throughout the MWIR region and into the LWIR region is provided. The quantum nanomaterials may include tin telluride (SnTe) nanomaterials and/or lead tin telluride (Pb.sub.xSn.sub.1-xTe) nanomaterials. Additionally, a method of manufacturing nanomaterial that is tunable for detecting IR radiation in selected regions, such as throughout the MWIR region and into the LWIR region, is also provided.

The invention is directed to a method for producing non-oxide semiconductor nanoparticles, the method comprising: (a) subjecting a combination of reaction components to conditions conducive to microbially-mediated formation of non-oxide semiconductor nanoparticles, wherein said combination of reaction components comprises i) anaerobic microbes, ii) a culture medium suitable for sustaining said anaerobic microbes, iii) a metal component comprising at least one type of metal ion, iv) a non-metal component comprising at least one non-metal selected from the group consisting of S, Se, Te, and As, and v) one or more electron donors that provide donatable electrons to said anaerobic microbes during consumption of the electron donor by said anaerobic microbes; and (b) isolating said non-oxide semiconductor nanoparticles, which contain at least one of said metal ions and at least one of said non-metals. The invention is also directed to non-oxide semiconductor nanoparticle compositions produced as above and having distinctive properties.

The present invention disclosed use of lactam as a solvent in the preparation of nanomaterials by precipitation method, sol-gel method or high temperature pyrolysis. These methods are able to recycle lactam solvent, which meet requirements of environmental protection.

An electrically conductive thin film including a compound represented by Chemical Formula 1 and having a layered crystal structure:
A.sub.xM.sub.yCh.sub.z  Chemical Formula 1 wherein A is V, Nb, or Ta, M is Ni, Co, Fe, Pd, Pt, Ir, Rh, Si, or Ge, Ch is S, Se, or Te, x is a number from 1 to 3, y is a number from 1 to 3, and z is a number from 2 to 14.

A methodology for synthesizing a nanoparticle batch, such as but not limited to a metal chalcogenide nanoparticle batch and further such as but not limited to a metal sulfide nanoparticle batch is predicated upon an expectation and observation that at elevated concentrations of at least one reactant material within a heat-up nanoparticle batch synthesis method, the resulting nucleated batch comprises nanoparticles that may be dimensionally focused to provide a substantially monodisperse nanoparticle batch. The embodied methodology is also applicable to a continuous reactor. The embodied methodology also considers viscosity as a dimensionally focusing result effective variable.

A process for preparing alloy products is described using a self-sustaining or self-propagating SHS-type combustion process with point-source ignition, preferably a laser, in a pressurized vessel. Binary, ternary and quaternary alloys can be formed with control over polycrystalline structure and bandgap. Methods to tune the bandgap and the alloys formed are described. The alloy products may be doped. Preferably sulfides, tellurides or selenides are formed. Cooling during reaction takes place.

A method embodiment involves preparing single metal or mixed transition metal chalcogenide using exfoliation of two or more different bulk transition metal dichalcogenides in a manner to form an intermediate hetero-layered transition metal chalcogenide structure, which can be treated to provide a single-phase transition metal chalcogenide.

Semiconductor structures having a nanocrystalline core and corresponding nanocrystalline shell and insulator coating, wherein the semiconductor structure includes an anisotropic nanocrystalline core composed of a first semiconductor material, and an anisotropic nanocrystalline shell composed of a second, different, semiconductor material surrounding the anisotropic nanocrystalline core. The anisotropic nanocrystalline core and the anisotropic nanocrystalline shell form a quantum dot. An insulator layer encapsulates the nanocrystalline shell and anisotropic nanocrystalline core.