N-type polycrystalline silicon ingot casting device and ingot casting method

Abstract

The invention provides an N-type polycrystalline silicon ingot casting device which comprises an ingot casting furnace, wherein the ingot casting furnace is internally provided a crucible; a storage cabin for storing a silicon material is arranged at the top end of the ingot casting furnace; the storage cabin and the crucible are connected with a conveying tube; discharge of the silicon material inside the storage cabin is controlled by a discharge valve. The device is characterized in that a high-power laser unit is arranged at the top end of the ingot casting furnace; the high-power laser unit is provided with a laser source; the laser source is adopted for radiation scanning on the silicon material fed into the crucible from the storage cabin; a vacuum air sucking valve and an inert gasinlet valve are respectively arranged outside the storage cabin; the storage cabin is further provided with a heating unit for preheating the silicon material inside the storage cabin. The inventionfurther discloses an ingot casting method with the device provided by the invention.

Description

technical field [0001] The invention provides an ingot casting device and method for solar crystal ingots, in particular to an N-type polysilicon ingot casting device and an ingot casting method with secondary feeding equipment. Background technique [0002] With the increase in the use of alternative energy sources, solar energy has become an alternative energy source with great cost advantages due to its relatively low construction cost and quick return on cost; among many solar cell materials, silicon-based solar cells, because of their The advantages of high photoelectric conversion efficiency and mature technology have made it a widely used material for solar cell production. [0003] The production of silicon crystal ingots is to melt high-purity silicon raw materials through high-temperature-resistant crucibles, control the preparation conditions, and carry out the silicon crystal ingot casting process, so as to produce solar cell materials with good material stress a...

AI Technical Summary

Problems solved by technology

However, in the process of N-type polysilicon ingot casting, the VA dopant has a small segregation coefficient, which causes the element to be unevenly distributed in the ingot, resulting in an excessively large distribution range of resistance values, which affects the utilization rate of the ingot.

In the previous silicon material addition procedure, on the one hand, it was impossible to adjust the dopant ratio in time to achieve the purpose of narrowing the distribution range of resistance value, which affected the photoelectric conversion rate; on the other hand, direct solid-state feeding would cause silicon material and silicon liquid The temperature difference between them is too large, resulting in material stress and thermal field effect, which will increase crystal defects, reduce the availability of polycrystalline ingots, and increase production costs and time costs.

Images