The present disclosure relates to tellurite crystals, growing methods of the same, and applications thereof; the crystals a chemical formula of MTe.sub.3O.sub.8, wherein M=Ti, Zr, Hf, which belongs to an Ia-3 space group of a cubic crystal system, wherein a transmittance waveband ranges from visible light to infrared light, with a transparency ≥70%. According to the present disclosure, a growing method of a tellurite crystal is provided, wherein the crystal may be grown using a flux method, a Czochralski method, or a Bridgman-Stockbarger method. The tellurite crystals may be used as an acousto-optic crystal for fabricating an optical modulation device. The present disclosure takes the lead internationally in growing the tellurite single crystals, the size and quality of which sufficiently meet the demands of practical applications of the tellurite single crystals.

The present disclosure relates to tellurite crystals, growing methods of the same, and applications thereof; the crystals a chemical formula of MTe.sub.3O.sub.8, wherein M=Ti, Zr, Hf, which belongs to an Ia-3 space group of a cubic crystal system, wherein a transmittance waveband ranges from visible light to infrared light, with a transparency ≥70%. According to the present disclosure, a growing method of a tellurite crystal is provided, wherein the crystal may be grown using a flux method, a Czochralski method, or a Bridgman-Stockbarger method. The tellurite crystals may be used as an acousto-optic crystal for fabricating an optical modulation device. The present disclosure takes the lead internationally in growing the tellurite single crystals, the size and quality of which sufficiently meet the demands of practical applications of the tellurite single crystals.

Disclosed in the present invention is a nonlinear optical crystal. The chemical formula of the nonlinear optical crystal is MHgGeSe.sub.4, M being selected from Ba or Sr. The nonlinear optical crystal has no symmetrical center, belongs to an orthorhombic crystal system, and has a space group Ama2. The nonlinear optical crystal is an infrared nonlinear optical crystal, and has the advantages of great nonlinear optical effect, wide light transmitting band, high hardness, good mechanical properties, breakage resistance, deliquescence resistance, easiness in processing and preserving, etc. Also disclosed in the present invention are a method for preparing the nonlinear optical crystal and application thereof.

Disclosed in the present invention is a nonlinear optical crystal. The chemical formula of the nonlinear optical crystal is MHgGeSe.sub.4, M being selected from Ba or Sr. The nonlinear optical crystal has no symmetrical center, belongs to an orthorhombic crystal system, and has a space group Ama2. The nonlinear optical crystal is an infrared nonlinear optical crystal, and has the advantages of great nonlinear optical effect, wide light transmitting band, high hardness, good mechanical properties, breakage resistance, deliquescence resistance, easiness in processing and preserving, etc. Also disclosed in the present invention are a method for preparing the nonlinear optical crystal and application thereof.

Disclosed is a method for synthesizing single crystalline molybdenum disulfide via a hydrothermal process that minimizes or eliminates carbon byproducts. The method involves providing two components, including a source of molybdenum and a mineralizer solution, to an inert reaction vessel, heating one zone sufficiently to dissolve the source of molybdenum in the mineralizer solution, and heating a second zone to a lower temperature to allow thermal transport to drive the dissolved material to the second zone, and then precipitate MoS.sub.2 on a seed crystal.

In an embodiment, a method includes providing a substrate and epitaxially growing a semiconductor layer of a semiconductor material on the substrate using physical vapor deposition, wherein the semiconductor material has a tetragonal phase, wherein the semiconductor material has the general formula: (In.sub.1-xM.sub.x)(Te.sub.1-yZ.sub.y), and wherein M=Ga, Zn, Cd, Hg, Tl, Sn, Pb, Ge, or combinations thereof, Z═As, S, Se, Sb, or combinations thereof, x=0-0.1, and y=0-0.1, or wherein the semiconductor material has the general formula: (In.sub.1-xTl.sub.x)(Te.sub.1-ySe.sub.y) with x=0-1 and y=0-1.

The present invention provides an optical ZnS material and a preparation method thereof, wherein the preparation method comprises: charging zinc and sulfur into a first crucible and a feeding device of a chemical vapor deposition furnace, respectively; heating the first crucible, the second crucible and a deposition chamber, and charging sulfur into the second crucible through the feeding device; introducing an inert carrier gas into the first crucible, and introducing an inert carrier gas and hydrogen into the second crucible, flowing the carrier gas containing zinc vapor and sulfur vapor respectively into the deposition chamber through pipelines to deposit ZnS, and supplying the second crucible with sulfur regularly and quantitatively through the feeding device during the deposition process to maintain a saturated vapor pressure of sulfur in a range of 0.8 to 1.8 KPa. The preparation method of the present invention does not generate H.sub.2S; thus it can avoid the formation of hydrogen-zinc complexes by H ions produced from the decomposition of H.sub.2S and Zn vapor, which would otherwise affect the transmittance and emissivity of ZnS material. (FIG. 4B)

The present invention provides an optical ZnS material and a preparation method thereof, wherein the preparation method comprises: charging zinc and sulfur into a first crucible and a feeding device of a chemical vapor deposition furnace, respectively; heating the first crucible, the second crucible and a deposition chamber, and charging sulfur into the second crucible through the feeding device; introducing an inert carrier gas into the first crucible, and introducing an inert carrier gas and hydrogen into the second crucible, flowing the carrier gas containing zinc vapor and sulfur vapor respectively into the deposition chamber through pipelines to deposit ZnS, and supplying the second crucible with sulfur regularly and quantitatively through the feeding device during the deposition process to maintain a saturated vapor pressure of sulfur in a range of 0.8 to 1.8 KPa. The preparation method of the present invention does not generate H.sub.2S; thus it can avoid the formation of hydrogen-zinc complexes by H ions produced from the decomposition of H.sub.2S and Zn vapor, which would otherwise affect the transmittance and emissivity of ZnS material. (FIG. 4B)

The present invention relates to an orthogonal-phase compound and its nonlinear optical (NLO) crystal of BaGa.sub.7Se.sub.7, its producing method and uses thereof. Polycrystalline orthogonal-phase BaGa.sub.4Se.sub.7 was prepared by a high-temperature solid-phase reaction in a sealed silica tube. Large size single crystals of orthogonal-phase BaGa.sub.4Se.sub.7 could be prepared by the flux method or Bridgman method. BaGa.sub.4Se.sub.7 crystallizes in the point group mm2. Orthogonal-phase BaGa.sub.4Se.sub.7 has a powder second harmonic generation (SHG) efficiency of about 5 times that of AgGaS.sub.2 and is phase-matchable. The orthogonal-phase BaGa.sub.4Se.sub.7 is non-hygroscopic and has good mechanical properties, which makes it easy to cut, polish, and coat by normal processing. The orthogonal-phase BaGa.sub.4Se.sub.7 crystal has never been cracked during cutting and polishing. The orthogonal-phase compound and NLO crystal of BaGa.sub.4Se.sub.7 can be used as NLO devices.

The present invention relates to an orthogonal-phase compound and its nonlinear optical (NLO) crystal of BaGa.sub.7Se.sub.7, its producing method and uses thereof. Polycrystalline orthogonal-phase BaGa.sub.4Se.sub.7 was prepared by a high-temperature solid-phase reaction in a sealed silica tube. Large size single crystals of orthogonal-phase BaGa.sub.4Se.sub.7 could be prepared by the flux method or Bridgman method. BaGa.sub.4Se.sub.7 crystallizes in the point group mm2. Orthogonal-phase BaGa.sub.4Se.sub.7 has a powder second harmonic generation (SHG) efficiency of about 5 times that of AgGaS.sub.2 and is phase-matchable. The orthogonal-phase BaGa.sub.4Se.sub.7 is non-hygroscopic and has good mechanical properties, which makes it easy to cut, polish, and coat by normal processing. The orthogonal-phase BaGa.sub.4Se.sub.7 crystal has never been cracked during cutting and polishing. The orthogonal-phase compound and NLO crystal of BaGa.sub.4Se.sub.7 can be used as NLO devices.