4 results about "Cadmium" patented technology

The invention discloses a novel single-crystal furnace for a zinc cadmium telluride single crystal and a growth process. A furnace body and a heating power supply are provided; a quartz tube is arranged in the hearth; a crucible is arranged in the quartz tube; a seed crystal cavity is form on a lower part in the crucible; a support frame is arranged below the quartz tube; sealing plugs are arranged at an upper end and a lower end of the hearth; nine heating areas are arranged in the hearth of the furnace body from top to bottom in sequence; each heating area is provided with an electrode which communicates with a power supply cabinet, a cable and a self-control switch; a temperature control system is provided further. The novel single-crystal furnace has the advantages of suitability for growth of the zinc cadmium telluride single crystal, omission of mechanical movement, formation of a no-vibration growth environment, realization of segmental flexible control of the growth temperature, great reduction in time for heating and smelting materials and receiving the seed crystal, and improvement on the quality and production efficiency of the single crystal. Moreover, the novel single-crystal furnace has the advantages of compact entire structure, small floor area, lower equipment cost, easiness in mounting, programmed control, accurate running, and stable repeatability. By adopting the novel single-crystal furnace, a large-diameter zinc cadmium telluride single crystal can be generated rapidly.

The invention provides a preparation method of ZnCdSe/ZnS quantum dots. The method comprises the following steps that 1, a zinc source, a cadmium source, organic acid and/or organic amine and an organic solvent are stirred and heated to be dissolved after shielding gas is introduced to obtain a zinc and cadmium mixed pro-solution; 2, the solution is heated to 200-350 DEG C, and then a selenium source is injected into the solution within 30 s; 3, a sulfur source or sulfur and zinc source mixed solution is added drop by drop; 4, the temperature of 200-350 DEG C is kept constant, then cooling is performed to reach the room temperature, and separation and purification are performed to obtain ZnCdSe/ZnS quantum dots. The preparation method of the ZnCdSe/ZnS quantum dots is safety to implement, simple, controllable, low in cost, and capable of achieving repetition and amplification; the obtained quantum dots are uniform and controllable in size and appearance, the monodipserity is good, the fluorescence quantum yield is high, and the good stability on the high-temperature, washing and water dissolution modification and other conditions is good.

The invention discloses a mercury cadmium telluride avalanche diode detector capable of modulating a surface energy band. By adding an electrode above a passivation layer of a pn junction depletion region, the pn junction energy band at the interface between the passivation layer and the mercury cadmium telluride can be modulated, and the pn junction at the interface between the passivation layerand the mercury cadmium telluride tends to be flat, thereby suppressing surface generation-recombination, surface tunneling, and surface leakage currents. The detector has the advantages that the surface energy band of the pn junction region can be modulated to be flat, and the surface leakage current is suppressed to enable the diode to work in the Geiger mode under the reverse large bias voltage, which is advantageous for solving the problem that the mercury cadmium telluride avalanche diode device of the conventional structure may have large leakage current at the surface when the reverse bias voltage is greater than the avalanche breakdown voltage, causes the photodiode to undergo thermal-electric breakdown, and limits signal detection in a linear mode.

The invention provides a heavy metal cadmium composite foliar resistance control agent which comprises the following components in percentage by mass: 10%-15% of soluble silicon, 5%-10% of glycerol, 1%-2% of surfactant, 0.5%-1% of thickener and 72%-83.5% of distilled water, and the principles of silicon and glycerol for inhibiting rice grains from enriching heavy metal cadmium are combined, so that the cadmium reduction effect is more outstanding and more stable; meanwhile, crop growth can be promoted, safe production of heavy metal cadmium polluted farmlands is achieved, grain production safety is improved, the preparation method and the use method of the fertilizer are convenient, and the problems that in the prior art, the production process is complex, cost is high, and generalizability is poor are solved.