Method and device for efficient removal of impurity oxygen from polysilicon by electron beam melting

Abstract

Belonging to the field of polysilicon purification, the invention in particular relates to a method and device for efficient removal of impurity oxygen from polysilicon by electron beam melting, and breaks the traditional electron beam melting mode to carry out electron beam deoxygenation smelting by means of a diversion trench rather than in a melting crucible. As a silicon liquid can spread in a diversion area, the specific surface area increases, and the electron beam melting deoxygenation effect can be better. According to the method and device provided by the invention, (1) the technological method and use of electron beam deoxygenation are put forward, the problem of difficult removal of impurity oxygen from polysilicon is solved, and the oxygen content can be reduced to less than 0.0571ppmw, thus meeting the requirement of solar cells for polysilicon ingot oxygen content; (2) the polysilicon material efficient banded deoxygenization technology can increase the silicon liquid surface area by over 30% and shorten the deoxygenation time by more than 20%; and (3) continuous production can be realized, and the production efficiency can be improved by more than 35%.

Description

technical field

[0001] The invention belongs to the field of polysilicon purification, and in particular relates to a method and a device for efficiently removing impurity oxygen in polysilicon by electron beam smelting. 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 propor...

Examples

Embodiment 1

[0026] like figure 1 As shown, a device for efficiently removing impurity oxygen in polysilicon by electron beam smelting includes a furnace body 1, and a water-cooled diversion groove 2 is arranged on the upper part of the furnace body 1. The diversion groove 2 is inclined from top to bottom, and the furnace body The side wall of 1 is connected with a feeding mechanism 5, and the discharge port of the feeding mechanism 5 is located above the high end of the diversion tank 2; the top of the furnace body 1 above the diversion tank 2 is connected with an electron gun 3 for melting and a melting furnace. An electron gun 4 is used; a solidification crucible 6 is provided at the inner bottom of the furnace body 1 below the pouring port of the diversion tank 2 .

[0027] The solidification crucible 6 is a copper crucible with water cooling. For the solidified crucible 6, both graphite crucible and quartz crucible can be used, but when the silicon liquid is poured downward, it is ea...

Embodiment 2

[0030] The device in Example 1 is used to efficiently remove impurity oxygen in polysilicon by electron beam smelting.

[0031](1) Material preparation: wash and dry the polysilicon material with a particle size of 10-12 mm and an oxygen content of 20 ppmw and put it into the feeding mechanism 5; put the silicon material that has been purified by electron beam melting into the inner bottom of the solidification crucible 6 as a solidification Primer;

[0032] (2) Pretreatment: Turn on the cooling water circulation for the electron beam melting furnace and diversion tank 2, vacuumize the inside of the electron beam melting furnace to below 0.05Pa, and vacuum the electron gun 3 for melting and the electron gun 4 for melting Processing, pumping to below 0.005Pa, and then preheating, set the beam current of the electron beam to 150mA, after preheating for 15min, turn off the preheating;

[0033] (3) Smelting and purification: start the feeding mechanism 5, continuously add silicon...

Embodiment 3

[0035] The device in Example 1 is used to efficiently remove impurity oxygen in polysilicon by electron beam smelting.

[0036] (1) Material preparation: wash and dry the polysilicon material with a particle size of 10-12 mm and an oxygen content of 10 ppmw and put it into the feeding mechanism 5; put the silicon material that has been purified by electron beam melting into the inner bottom of the solidification crucible 6 as a solidification Primer;

[0037] (2) Pretreatment: Turn on the cooling water circulation for the electron beam melting furnace and diversion tank 2, vacuumize the inside of the electron beam melting furnace to below 0.05Pa, and vacuum the electron gun 3 for melting and the electron gun 4 for melting Processing, pumping to below 0.005Pa, and then preheating, set the beam current of the electron beam to 200mA, preheat the electron gun for 10 minutes, and then turn off the preheating;

[0038] (3) Melting and purification: start the feeding mechanism 5, co...

technical field

[0001] The invention belongs to the field of polysilicon purification, and in particular relates to a method and a device for efficiently removing impurity oxygen in polysilicon by electron beam smelting. 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 propor...

Examples

Embodiment 1

[0026] like figure 1 As shown, a device for efficiently removing impurity oxygen in polysilicon by electron beam smelting includes a furnace body 1, and a water-cooled diversion groove 2 is arranged on the upper part of the furnace body 1. The diversion groove 2 is inclined from top to bottom, and the furnace body The side wall of 1 is connected with a feeding mechanism 5, and the discharge port of the feeding mechanism 5 is located above the high end of the diversion tank 2; the top of the furnace body 1 above the diversion tank 2 is connected with an electron gun 3 for melting and a melting furnace. An electron gun 4 is used; a solidification crucible 6 is provided at the inner bottom of the furnace body 1 below the pouring port of the diversion tank 2 .

[0027] The solidification crucible 6 is a copper crucible with water cooling. For the solidified crucible 6, both graphite crucible and quartz crucible can be used, but when the silicon liquid is poured downward, it is ea...

Embodiment 2

[0030] The device in Example 1 is used to efficiently remove impurity oxygen in polysilicon by electron beam smelting.

[0031](1) Material preparation: wash and dry the polysilicon material with a particle size of 10-12 mm and an oxygen content of 20 ppmw and put it into the feeding mechanism 5; put the silicon material that has been purified by electron beam melting into the inner bottom of the solidification crucible 6 as a solidification Primer;

[0032] (2) Pretreatment: Turn on the cooling water circulation for the electron beam melting furnace and diversion tank 2, vacuumize the inside of the electron beam melting furnace to below 0.05Pa, and vacuum the electron gun 3 for melting and the electron gun 4 for melting Processing, pumping to below 0.005Pa, and then preheating, set the beam current of the electron beam to 150mA, after preheating for 15min, turn off the preheating;

[0033] (3) Smelting and purification: start the feeding mechanism 5, continuously add silicon...

Embodiment 3

[0035] The device in Example 1 is used to efficiently remove impurity oxygen in polysilicon by electron beam smelting.

[0036] (1) Material preparation: wash and dry the polysilicon material with a particle size of 10-12 mm and an oxygen content of 10 ppmw and put it into the feeding mechanism 5; put the silicon material that has been purified by electron beam melting into the inner bottom of the solidification crucible 6 as a solidification Primer;

[0037] (2) Pretreatment: Turn on the cooling water circulation for the electron beam melting furnace and diversion tank 2, vacuumize the inside of the electron beam melting furnace to below 0.05Pa, and vacuum the electron gun 3 for melting and the electron gun 4 for melting Processing, pumping to below 0.005Pa, and then preheating, set the beam current of the electron beam to 200mA, preheat the electron gun for 10 minutes, and then turn off the preheating;

[0038] (3) Melting and purification: start the feeding mechanism 5, co...

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