广州英语翻译
8.2.7 Standard solution for silicon dioxide (containing SiO2 1 mg/mL).
Weigh 0.2000g SiO2 (99.99%) that is pre-roasted in platinum crucible at 1,000℃ for 2h and
cooled in drier to ambient temperature, and add 2g~3g anhydrous sodium carbonate, cover the
crucible and leave a little clearance, place the crucible in high temperature furnace to be molten at
1,000℃ for 5~10 min, take it out and cool. Place the crucible into PTFE beaker with 100 mL
boiling water, and heat at low temperature to leach the molten lump till the solution is clear, wash
the crucible and cover with hot water, cool it to room temperature. All the solution is transferred
into 200 mL volumetric flask, and the solution is diluted to mark with water, shake to blend, and
keep the solution in plastic bottle.
8.4.1 Place the test sample into crucible with 2g mixed flux (8.2.1), blend the mixture, then cover
it with 1g mixed flux (8.2.1), cover the crucible and leave a small clearance, put the crucible into
high temperature furnace at 800~900℃, heat up to 1,000 ~ 1,100℃, melt the mixture for 5 min ~
15 min, then take the crucible out, rotate the crucible to make the molten substance adhere to inner
wall of crucible evenly, then cool.
8.4.2 Wipe the external wall of crucible clean with filter paper, then place the crucible into 200 mL
beaker with 60 mL boiling hydrochloric acid (8.2.5), heat at low temperature to leach the molten
substance till the solution is clear, wash the crucible and cover with water, cool the solution to
room temperature, and transfer all the solution into 100 mL volumetric flask, dilute with water to
mark, and shake to blend the solution.
要获得纯硅,必须借助碳将硅砂(二氧化硅)中的氧提取出来。硅和氧原子结合非常紧密,硅砂中的碳和氧元素只有在极高温度下(约1800℃)才能结合生成二氧化碳。二氧化碳排出后,剩下的就是硅。这一过程能耗极高,每公斤硅原料需消耗14 度电。通过此种方法提取的硅材料仍含有1%的杂质,而杂质含量要求不得超过0.0000001%(十亿分之一)。因此,原硅完全不适用于计算机或光伏产品。基于此点,需采用纯盐酸将其转换为三氯氢硅。三氯氢硅沸点约为30℃,需在30 多米高的大型系统内进行提纯。经提纯的“火硅”,杂质含量不到十亿分之一。三氯硅烷与高纯度氢气进行反应,将“火硅”转换为固态硅。基于此目的,气体混合物与高纯度硅“细棒”接触,析出新的小片无需的多晶硅晶体。硅棒越来越粗,直径达到180 毫米时,过程终止,硅棒破为碎片。高科技文明发展所需的材料制备完成。但此
时的硅材料仍缺乏内部均匀性,为此,基本上可采用四种方法北京翻译公司。
To obtain pure silicon, the oxygen must be extracted from silica sand (SiO2) with the help
of carbon. As silicon and oxygen are very closely related atomically, the carbon and
oxygen in silica sand only combine to form carbon dioxide at very high temperatures
(approx.1,800°C). The carbon dioxide is drained off and silicon is left behind. This process
is highly energyintensive, requiring approx. 14 kWh per kg of raw silicon. Raw silicon
extracted in this way still contains approx. 1% impurities. However, a purity level of at least
0.0000001% (1ppb) is required. The raw silicon is therefore still totally unsuitable for
computer or photovoltaic purposes. For this reason, using pure hydrochloric acid, it is
converted to trichlorosilane, a liquid with a boiling point of approx. 30°C that is distilled in
large systems over 30 meters high. The distillate, „fired silicon“, only contains impurities
below 1 ppb. The return to solid silicon is achieved via a reaction of trichlorosilane with
high-purity hydrogen. To this end, a mixture of the gases is put into contact with hot „thin
rods“ of high-purity silicon, on which new silicon precipitates in small, disordered crystals
as polysilicon. The rods become increasingly thick. When a diameter of approx. 180mm is
reached, the process is ended and the rod is broken into small pieces. The material that
keeps the high-tech civilization moving is ready. However, it still lacks internal regularity.
Essentially, there are four methods for this.