Techniques disclosed herein relate to sol-gel materials that include at least one metal halide precursor and at least one alcohol. After being annealed, the metal in the metal halide is in at least two different oxidation states, both of which are stable and transparent to visible light. By producing a mixture of the same metal in multiple oxidation states that are all transparent to visible light, an amorphous state of the sol-gel material without any noticeable domain formation that would otherwise distribute stress locally and lead to voiding inside nano-gratings to be overcoated is obtained. Highly condensed states of the sol-gel have refractive index values in the 1.7-2.2 range, without sacrificing recessed-feature fill.

Techniques disclosed herein relate to sol-gel materials that include at least one metal halide precursor and at least one alcohol. After being annealed, the metal in the metal halide is in at least two different oxidation states, both of which are stable and transparent to visible light. By producing a mixture of the same metal in multiple oxidation states that are all transparent to visible light, an amorphous state of the sol-gel material without any noticeable domain formation that would otherwise distribute stress locally and lead to voiding inside nano-gratings to be overcoated is obtained. Highly condensed states of the sol-gel have refractive index values in the 1.7-2.2 range, without sacrificing recessed-feature fill.

The present invention is a method for producing perovskite type quantum dots, wherein, using a plurality of precursor solutions each containing a different element, each of the plurality of precursor solutions is heated and sprayed as an aerosol of the precursor solution, and the plurality of aerosols are collided to cause a gas phase reaction, dropping in a solvent to synthesize core particles containing the different elements. This provides a method for producing quantum dots that enables control of the particle size and yields nanoparticles with a uniform particle size even in large-scale synthesis.

The present invention is a method for producing perovskite type quantum dots, wherein, using a plurality of precursor solutions each containing a different element, each of the plurality of precursor solutions is heated and sprayed as an aerosol of the precursor solution, and the plurality of aerosols are collided to cause a gas phase reaction, dropping in a solvent to synthesize core particles containing the different elements. This provides a method for producing quantum dots that enables control of the particle size and yields nanoparticles with a uniform particle size even in large-scale synthesis.

Described are methods and compositions for processes of preparing a radioactive solution of Sn-117m tetraiodide. Aspects include reacting a radioactive solid Sn containing Sn-117m with a solution of I.sub.2 in an organic solvent at a temperature and for a duration sufficient to result in the formation of Sn-117m tetraiodide. Then, the organic solvent is removed by evaporation to leave dry Sn-117m tetraiodide. The organic solvent is a low boiling point solvent capable of dissolving I.sub.2 and Sn tetraiodide. The organic solvent is selected from the group consisting of an alcohol and a chlorinated solvent. In embodiments may be selected from the group consisting of dichloromethane, trichloromethane, tetrachloromethane, or mixtures thereof. In embodiments, the organic solvent excludes alcohol. The I.sub.2 may be in a slight molar excess to the radioactive solid Sn. The method may further include distilling the reactants to remove excess I.sub.2 from the distillate.

Described are methods and compositions for processes of preparing a radioactive solution of Sn-117m tetraiodide. Aspects include reacting a radioactive solid Sn containing Sn-117m with a solution of I.sub.2 in an organic solvent at a temperature and for a duration sufficient to result in the formation of Sn-117m tetraiodide. Then, the organic solvent is removed by evaporation to leave dry Sn-117m tetraiodide. The organic solvent is a low boiling point solvent capable of dissolving I.sub.2 and Sn tetraiodide. The organic solvent is selected from the group consisting of an alcohol and a chlorinated solvent. In embodiments may be selected from the group consisting of dichloromethane, trichloromethane, tetrachloromethane, or mixtures thereof. In embodiments, the organic solvent excludes alcohol. The I.sub.2 may be in a slight molar excess to the radioactive solid Sn. The method may further include distilling the reactants to remove excess I.sub.2 from the distillate.

A complex has a structure of formula (1A): SnX.sub.n.Math.(m)L, wherein X is at least one type of halogen atoms, L is a polar solvent molecule, n is a value from 1.5 to 2.5, and m is a value from 0.3 to 1.9. A perovskite compound has a structure of formula (2A): RSnX.sub.j, wherein Sn has an oxidation number from 1.5 to 2.5, R is at least one type of a monovalent cation, X is at least one type of halogen atoms, and j is a value from 2.5 to 3.5, and the perovskite compound is free of tin oxide; or a perovskite compound has a structure of formula (2B): R.sub.2M.sup.2BiX.sub.1, wherein R is at least one type of a monovalent cation, X is at least one type of halogen atoms; M.sup.2 is a monovalent metal, and i is a value from 5.0 to 7.0.

Described are methods and compositions for processes of preparing a radioactive solution of Sn-117m tetraiodide. Aspects include reacting a radioactive solid Sn containing Sn-117m with a solution of I.sub.2 in an organic solvent at a temperature and for a duration sufficient to result in the formation of Sn-117m tetraiodide. Then, the organic solvent is removed by evaporation to leave dry Sn-117m tetraiodide. The organic solvent is a low boiling point solvent capable of dissolving I.sub.2 and Sn tetraiodide. The organic solvent is selected from the group consisting of an alcohol and a chlorinated solvent. In embodiments may be selected from the group consisting of dichloromethane, trichloromethane, tetrachloromethane, or mixtures thereof. In embodiments, the organic solvent excludes alcohol. The I.sub.2 may be in a slight molar excess to the radioactive solid Sn. The method may further include distilling the reactants to remove excess I.sub.2 from the distillate.

Described are methods and compositions for processes of preparing a radioactive solution of Sn-117m tetraiodide. Aspects include reacting a radioactive solid Sn containing Sn-117m with a solution of I.sub.2 in an organic solvent at a temperature and for a duration sufficient to result in the formation of Sn-117m tetraiodide. Then, the organic solvent is removed by evaporation to leave dry Sn-117m tetraiodide. The organic solvent is a low boiling point solvent capable of dissolving I.sub.2 and Sn tetraiodide. The organic solvent is selected from the group consisting of an alcohol and a chlorinated solvent. In embodiments may be selected from the group consisting of dichloromethane, trichloromethane, tetrachloromethane, or mixtures thereof. In embodiments, the organic solvent excludes alcohol. The I.sub.2 may be in a slight molar excess to the radioactive solid Sn. The method may further include distilling the reactants to remove excess I.sub.2 from the distillate.

A light valve containing ABX.sub.3 perovskite particles (200) suspended in a liquid suspension (300) that can control light transmittance is provided. The preferable ABX.sub.3 perovskite particles (200) are halide ABX.sub.3 perovskite particles wherein A is at least one of Cs.sup.+, CH.sub.3NH.sub.3.sup.+, and Rb.sup.+, B is at least one of Pb.sup.2+, Ge.sup.2+, and Sn.sup.2+, and X is at least one of Cl.sup., Br.sup., and I.sup.. Use of the light valve in the manufacture of a light control device and a method of controlling light transmittance by using the light valve are also provided.