The electroluminescent element includes a QD layer. QD phosphor particles contained in the QD layer are nanocrystals containing zinc and selenium, or zinc, selenium, and sulfur. A fluorescent half width of the QD phosphor particles is 25 nm or less, and a fluorescent peak wavelength of the QD phosphor particles is 410 nm or more and 470 nm or less. The film thickness of the QD layer is 12 nm or more and 49 nm or less.

The electroluminescent element includes a QD layer and a hole transport layer. QD phosphor particles contained in the QD layer are nanocrystals containing zinc and selenium, or zinc, selenium, and sulfur. A fluorescent half width of the QD phosphor particles is 25 nm or less, and a fluorescent peak wavelength of the QD phosphor particles is 410 nm or more and 470 nm or less. The hole transport layer includes poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)]. A film thickness of the hole transport layer is 10 nm or more and 57 nm or less.

A chalcogen-containing compound of the following Chemical Formula 1 which exhibits excellent phase stability at a low temperature, particularly at a temperature corresponding to the driving temperature of a thermoelectric element, and also exhibits an excellent thermoelectric performance index through an increase in a power factor and a decrease in thermal conductivity, a method for preparing the same, and a thermoelectric element including the same:
V.sub.1-xM.sub.xSn.sub.4Bi.sub.2Se.sub.7-yTe.sub.y  [Chemical Formula 1]
In the above Formula 1, V is a vacancy, M is an alkali metal, x is greater than 0 and less than 1, and y is greater than 0 and less than or equal to 1.

Provided in this disclosure are oxidative dehydrogenation catalysts that include a mixed metal oxide having the empirical formula:
Mo.sub.1.0V.sub.0.12-0.49Te.sub.0.05-0.17Nb.sub.0.10-0.20O.sub.d
wherein d is a number to satisfy the valence of the oxide. The oxidative dehydrogenation catalyst is characterized by having XRD diffraction peaks (2θ degrees) at 22±0.2, 27±0.2, 28.0±0.2, and 28.3±0.1. The disclosure also provides methods of making the catalysts that include wet ball milling.

Disclosed herein are solar cells with kesterite-based absorbers that hold promise as a low-cost and durable technology to renewably produce electricity using solar energy conversion. The current state-of-the-art (SOA) for such kesterite solar cells is Cu.sub.2ZnSn(S,Se).sub.4 and novel materials are required to suppress the formation bandgap-fluctuation- and charge-carrier-recombination-inducing defects and eventually to achieve solar cell efficiencies higher than the SOA. Three important material properties that govern the efficiency of a solar cell are the concentrations of performance-degrading defects, band gap, and chemical stability. Disclosed here is a stable material, specifically Cu.sub.2CdGe(S,Se).sub.4, as a new candidate that can exhibit higher defect formation energies than Cu.sub.2ZnSnS.sub.4 and a nearly optimal bandgap, which can eventually result in higher solar-cell efficiencies in solar energy conversion.

A compound semiconductor which has an improved thermoelectric performance index together with excellent electrical conductivity, and thus may be utilized for various purposes such as a thermoelectric conversion material of thermoelectric conversion devices, solar cells, and the like, and to a method for preparing the same.

Ligand-capped inorganic particles, films composed of the ligand-capped inorganic particles, and methods of patterning the films are provided. Also provided are electronic, photonic, and optoelectronic devices that incorporate the films. The ligands that are bound to the inorganic particles are composed of a cation/anion pair. The anion of the pair is bound to the surface of the particle and at least one of the anion and the cation is photosensitive.

The present invention relates to a novel chalcogen-containing compound that exhibits excellent phase stability even at a temperature corresponding to the driving temperature of a thermoelectric element, and has a high output factor and thermoelectric figure of merit, a method for preparing the same, and a thermoelectric element including the same.

A compound containing Sn, Te and Mg, and further containing either one or both of Sb and Bi.

To provide Cd-free chalcopyrite-based quantum dots with a narrow fluorescence FWHM and a high fluorescence quantum yield. The quantum dots of the present invention contain AgIn.sub.xGa.sub.1-xS.sub.ySe.sub.1-y or ZnAgIn.sub.xGa.sub.1-xS.sub.ySe.sub.1-y (where 0≤x<1 and 0≤y≤1) and exhibit fluorescence properties including a fluorescence FWHM of less than or equal to 45 nm and a fluorescence quantum yield of greater than or equal to 35% in the green wavelength range to the red wavelength range.