Polysilicon pretreatment method regulating dropwise addition concentration of nitric acid

Abstract

The invention relates to a pretreatment method for polysilicon impurity detection, and particularly relates to a polysilicon pretreatment method regulating dropwise addition concentration of nitric acid. The method comprises the following steps: (1) weighing 0.1-0.5g of polysilicon sample in a PTFE (polytetrafluoroethylene) beaker; (2) adding 0.3-1ml of 1% mannitol solution into the PTFE beaker to drench the polysilicon sample; (3) adding 3-5ml of hydrofluoric acid having a mass percent of 49% into the PTFE beaker; (4) adding 0.5-1.0ml of nitric acid having a mass percent of 35%, then adding 1.0-2.0ml of nitric acid having a mass percent of 70%, and reacting until the polysilicon sample is completely dissolved; and (5) controlling the temperature to volatilize silicon, diluting to a specified volume, regulating the acidity, detecting the impurity content, and ending the operation. The polysilicon pretreatment method provided by the invention has the following advantages: element boron and other metal elements in the polysilicon can be simultaneously detected; meanwhile, the element boron reservation effect is remarkable, and the recovery rate can be increased from 80-85% to 95% or above; the method is simple and easy to operate; the evaporation drying time of the solution is shortened; and the polysilicon pretreatment efficiency is enhanced.

Description

technical field [0001] The invention relates to a pretreatment method for polysilicon impurity detection, in particular to a polysilicon pretreatment method for adjusting the nitric acid dripping concentration. Background technique [0002] At present, my country has become the world's largest energy production and consumption country, but the per capita energy consumption level is still very low. With the continuous development of the economy and society, my country's energy demand will continue to grow. In response to the current energy shortage, countries around the world are thinking deeply, and are working hard to improve energy efficiency, promote the development and application of renewable energy, and reduce the impact on energy consumption. Reliance on imported oil to enhance energy security. [0003] As one of the important development directions of renewable energy, solar photovoltaic power generation has developed rapidly in recent years, and its proportion is in...

AI Technical Summary

Problems solved by technology

[0006] At present, in the pretreatment process of polysilicon detection by ICP-AES, whether it is a powder sample or a granular sample, if the concentration of nitric acid is too high, a large amount of reaction heat will be generated during the digestion process, which will cause the formation of fluoroboric acid to decompose into trifluoro The volatilization of boron will lead to serious loss of boron element, resulting in a serious low accuracy of detection results; and if the concentration of nitric acid is low, it will increase the amount of liquid, prolong the evaporation time of the solution, and reduce the efficiency of polysilicon pretreatment