Method and system for regulating and controlling chemical ratio of lead iodide

Abstract

The invention relates to the field of material engineering and particularly relates to a method and a system for regulating and controlling a chemical ratio of lead iodide. The method comprises the steps of heating a mixture of lead and lead iodide polycrystals to 410-500 DEG C at a speed of 50-500 DEG C / h, and keeping the temperature for 10-200 hours after melting the mixture to a melt; and cooling the melt to a room temperature at a speed of 5-300 DEG C / min. In the mixture of the lead and the lead iodide polycrystals, the mass ratio of the lead to the lead iodide polycrystals is 1:10-5:10. The system comprises an ampoule and a holding furnace, wherein the ampoule is used for holding the mixture of the lead and the lead iodide polycrystals, and the ampoule is vacuumized and sealed after the mixture is put in the ampoule; and the ampoule filled with the mixture is heated and held by the holding furnace. Through the method and the system for regulating the chemical ratio of the lead iodide, the chemical ratio of the lead iodide polycrystals can be regulated and controlled.

Description

technical field [0001] The invention relates to the field of material engineering, in particular to a method and system for regulating the stoichiometric ratio of lead iodide. Background technique [0002] Lead iodide (PbI2) single crystal is one of the materials for making room temperature semiconductor nuclear radiation detectors, and the growth of lead iodide single crystal needs to use lead iodide polycrystalline powder or particles close to or reaching the ideal stoichiometric ratio as raw material. The stoichiometric ratio is the atomic molar ratio of different elements. Ideally, the atomic molar ratio of lead to iodine in a lead iodide single crystal is 1:2. If the atomic molar ratio of lead to iodine in the lead iodide polycrystal deviates from the ideal stoichiometric ratio, the lead iodide single crystal grown from this as a raw material will also deviate from the ideal stoichiometric ratio, thus failing to meet the requirements for making room temperature semicond...

AI Technical Summary

Problems solved by technology

[0004] Because iodine is easy to absorb water, it is easy to adhere to the container during the weighing process, and the vapor pressure of iodine is high, and it is easy to evaporate and escape during the process of vacuuming and sealing the quartz ampoule, so it is difficult to accurately measure the quality of iodine. Metering to control lead iodide stoichiometry

[0005] Further, when using the gas phase purification method to purify the synthesized lead iodide polycrystal, lead iodide will be partially decomposed into iodine and lead under high temperature conditions. The mixture of lead iodide makes the purified lead iodide polycrystalline rich in iodine, so it is not suitable to adjust the chemical ratio of lead iodide by means of the purification process

[0006] For the problems referred to above, there is no method for regulating the stoichiometric ratio of lead iodide polycrystals in the prior art

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