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CN-122013315-A - Monocrystalline silicon rod, preparation method thereof, silicon wafer and solar cell

CN122013315ACN 122013315 ACN122013315 ACN 122013315ACN-122013315-A

Abstract

The application discloses a monocrystalline silicon rod, a preparation method thereof, a silicon wafer and a solar cell, and belongs to the technical field of photovoltaic module preparation. The single crystal silicon rod comprises a head part and a tail part which are opposite along the length direction, the single crystal silicon rod is divided into n sections of silicon rod units from the head part to the tail part, the silicon rod units are provided with a first end and a second end which are opposite along the length direction, the single crystal silicon rod contains at least one of three five groups of elements and hydrogen element, the single crystal silicon rod meets K 1 ＝1-((C n‑1 -C Hydrogen gas )/(C n -C Hydrogen gas ), and 1E-3 is less than or equal to |K 1 is less than or equal to 1E-2. Because the III-V element and the hydrogen element are doped in the monocrystalline silicon rod, the effective segregation coefficient of the III-V element doping agent in the crystalline silicon in the silicon is improved through the interaction of the hydrogen and the III-V element, so that the resistivity consistency of the silicon rod is improved.

Inventors

  • ZHANG WENXIA
  • GAO SHENGJUN
  • LIU YOUYI
  • NIE SHUPING
  • WANG LIN
  • ZHOU YANJIE
  • GUO ZHIRONG
  • GUO QIAN
  • KANG XUEBING
  • WANG KAI
  • LIU JUNMEI
  • HAN PENG

Assignees

  • 内蒙古中环晶体材料有限公司

Dates

Publication Date
20260512
Application Date
20250430
Priority Date
20241108

Claims (20)

  1. 1. A single crystal silicon rod is characterized by comprising a head part and a tail part which are opposite along the length direction, wherein the single crystal silicon rod is divided into N sections of silicon rod units from the head part to the tail part, the silicon rod units are provided with a first end and a second end which are opposite along the length direction, the single crystal silicon rod contains a III-V element and a hydrogen element, and the single crystal silicon rod meets the following conditions: K 1 ＝1-((C n-1 -C Hydrogen gas )/(C n -C Hydrogen gas )), and 1E-3 is less than or equal to |K 1 is less than or equal to 1E-2; Wherein C Hydrogen gas represents the hydrogen element concentration per unit volume of the single crystal silicon rod, C n represents the III-V element concentration per unit volume of the silicon rod unit of the nth section at the second end, C n-1 represents the III-V element concentration per unit volume of the silicon rod unit of the nth section at the first end, and n is an integer greater than or equal to 1.
  2. 2. A single crystal silicon rod according to claim 1, wherein the dimensions of any one of the N-segment silicon rod units in the length direction are equal to each other, and/or, The dimension of any one of the N sections of silicon rod units in the length direction is A mm, which satisfies that A is more than or equal to 1 and less than or equal to 50, and/or, And N is an integer greater than or equal to 1 and less than or equal to 6000.
  3. 3. A single crystal silicon rod according to claim 1, wherein the concentration of hydrogen element C Hydrogen gas per unit volume in the single crystal silicon rod satisfies 2E+13cm -3 ≤C Hydrogen gas ≤1E+17cm -3 , or The concentration C Hydrogen gas of hydrogen element per unit volume in the single crystal silicon rod satisfies 1E+15cm -3 ≤C Hydrogen gas ≤7E+16cm -3 , or The concentration C Hydrogen gas of hydrogen element in unit volume in the single crystal silicon rod satisfies 3E+15cm -3 ≤C Hydrogen gas ≤6E+16cm -3 .
  4. 4. A single crystal silicon rod according to claim 1, wherein the concentration C n of the group III element per unit volume of the silicon rod unit of the nth stage at the second end satisfies 1E+14cm -3 ≤C n ≤8E+15cm -3 , or The concentration C n of the III-V element in the unit volume of the second end of the silicon rod unit of the nth section meets 2E+14cm -3 ≤C n ≤7E+15cm -3 or The group III element concentration C n per unit volume of the silicon rod unit of the nth section at the second end satisfies 1E+15cm -3 ≤C n ≤7E+15cm -3 .
  5. 5. A single crystal silicon rod according to claim 4, wherein the concentration C n-1 of the group III element per unit volume of the nth stage silicon rod unit at the first end satisfies 1E+14cm -3 ≤C n ≤8E+15cm -3 , or The group III-V element concentration C n-1 of the nth section of silicon rod unit in the unit volume of the first end is 2E+14cm -3 ≤C n ≤7E+15cm -3 , or The group III element concentration C n-1 per unit volume of the nth segment silicon rod unit at the first end satisfies 1E+15cm -3 ≤C n ≤7E+15cm -3 .
  6. 6. The single crystal silicon rod of claim 1, wherein the actual effective segregation coefficient of the element of group iii of the single crystal silicon rod is K Effective and effective , which satisfies the following conditions: K Effective and effective ＝K 0 /(K 0 +(1-K 0 )×EXP((-1)×(V/600)×δ/(10×D)))×(1-K 1 ); Wherein K 0 is the original effective segregation coefficient of III-V element in the monocrystalline silicon rod, V is the crystal pulling speed in mm/min, delta is the boundary layer thickness in mm, D is the diffusion coefficient in cm, and K 1 is the correction coefficient after the combination of hydrogen element and III-V element.
  7. 7. A single crystal silicon rod according to claim 6, wherein the boundary layer thickness delta is in the range of 0.005 to 0.05mm, and/or, The pulling speed V is in the range of 1.1-2.2 mm/min, and/or, The diffusion coefficient D is in the range of 0.0001-0.001cm.
  8. 8. The silicon single crystal rod according to claim 6, wherein the effective segregation coefficient K Effective and effective of the elements of III-V group of the silicon single crystal rod is 0.005≤K Effective and effective ≤0.38, or The actual effective segregation coefficient K Effective and effective of the III-V element of the single crystal silicon rod further satisfies the following conditions: K Effective and effective is 0.005 or less and 0.03 or The actual effective segregation coefficient K Effective and effective of the III-V element of the single crystal silicon rod further satisfies the following conditions: k Effective and effective is more than or equal to 0.005 and less than or equal to 0.028, or The actual effective segregation coefficient K Effective and effective of the III-V element of the single crystal silicon rod further satisfies the following conditions: 0.005≤K Effective and effective ≤0.018。
  9. 9. A single crystal silicon rod according to claim 1, wherein the resistivity of the single crystal silicon rod is ρΩ.cm, satisfying 0.1 ρ≤7, or The resistivity of the monocrystalline silicon rod is ρΩ cm, which satisfies that ρ is more than or equal to 0.4 and less than or equal to 1.5, or The resistivity of the monocrystalline silicon rod is ρΩ cm, which satisfies that ρ is more than or equal to 0.6 and less than or equal to 1.5, or The resistivity of the single crystal silicon rod is ρΩ cm, and ρ is more than or equal to 0.8 and less than or equal to 1.4.
  10. 10. A single crystal silicon rod according to claim 1, wherein said group iii element is selected from at least one of antimony, phosphorus, gallium, boron, arsenic.
  11. 11. A method for producing a single crystal silicon rod, comprising: providing a silicon raw material, and obtaining a monocrystalline silicon rod through the steps of material melting, re-casting, temperature stabilization, seeding, shouldering, isodiametric and ending; introducing hydrogen into the silicon raw material in at least one of the steps of material melting, re-casting, temperature stabilization, seeding, shouldering, isodiametric and ending; Before the growth of the monocrystalline silicon rod is finished, the doping concentration in the solidification process of the monocrystalline silicon rod is adjusted so as to control the doping amount ratio of the hydrogen element and the III-V element to meet the following conditions: K 1 ＝1-((C n-1 -C Hydrogen gas )/(C n -C Hydrogen gas )), and 1E-3 is less than or equal to |K 1 is less than or equal to 1E-2; Wherein C Hydrogen gas represents the hydrogen element concentration per unit volume of the single crystal silicon rod, C n represents the III-V element concentration per unit volume of the silicon rod unit of the nth section at the second end, C n-1 represents the III-V element concentration per unit volume of the silicon rod unit of the nth section at the first end, and n is an integer of 1 or more.
  12. 12. The method for producing a single crystal silicon rod according to claim 11, wherein the time for introducing hydrogen gas into the silicon raw material is as follows: the time t Total (S) ＝t 1 +t 2 +t 3 +t 4 +t 5 +t 6 +t 7 is set to be equal to the time, and t is more than or equal to 0.5h Total (S) is less than or equal to 82 hours; Wherein t Total (S) is the sum of the time of hydrogen gas introduction, t 1 is the time of hydrogen gas introduction in the material melting stage, t 2 is the time of hydrogen gas introduction in the re-feeding stage, t 3 is the time of hydrogen gas introduction in the temperature stabilizing stage, t 4 is the time of hydrogen gas introduction in the seeding stage, t 5 is the time of hydrogen gas introduction in the shoulder releasing stage, t 6 is the time of hydrogen gas introduction in the constant diameter stage, and t 7 is the time of hydrogen gas introduction in the ending stage.
  13. 13. The method for producing a single crystal silicon rod according to claim 12, wherein the time for introducing hydrogen gas into the silicon raw material further satisfies: t 1 ：t 2 ：t 3 ：t 4 ：t 5 ：t 6 ：t 7 ＝(0～10)：(0～8)：(0～2)：(0～1.5)：(0～3)： (0~55):(0~2)。
  14. 14. The method for producing a single crystal silicon rod according to claim 11, further comprising, after the re-casting step, introducing a shielding gas into the silicon raw material; Wherein the hydrogen and the shielding gas form a mixed gas, the volume percentage of the hydrogen in the mixed gas is 1-90%, preferably 5-90%, or The flow of the hydrogen is 0.0001-180 slpm, or The flow rate of the shielding gas is 40-200 slpm.
  15. 15. The method for producing a single crystal silicon rod according to claim 11, wherein the volatilization rate η of the group iii elements is controlled to satisfy: η=(H 1 /100mm)×100%-15%; Wherein H 1 is the liquid gap in the single crystal furnace, the unit is mm, the volatilization rate eta is more than or equal to 5% and less than or equal to 25%, and the liquid gap H 1 is more than or equal to 20mm and less than or equal to 40mm and H 1 .
  16. 16. The method for producing a silicon single crystal rod according to claim 15, wherein a guide cylinder is provided in the single crystal furnace, the guide cylinder includes a first section and a second section connected to each other, and the following conditions are satisfied: tan α=h 2 /W 1 , and 0≤tan α≤0.58; Wherein alpha is an included angle formed by the second section and the first direction, H 2 is the projection height of the second section in the second direction, and W 1 is the projection length of the second section in the first direction, and the first direction and the second direction are intersected.
  17. 17. The method for producing a single crystal silicon rod according to claim 11, characterized in that the step of adjusting the doping concentration during solidification of the single crystal silicon rod further comprises at least one of the following conditions: (a) Adding an antimony-containing raw material and a phosphorus-containing raw material into the silicon raw material, wherein the mass ratio of the silicon raw material to the antimony-containing raw material to the phosphorus-containing raw material is 1000 (0.05-0.5) (0.005-0.05); (b) The temperature range of the temperature stabilizing stage is 1450-1500 ℃, and the time is 1-2 hours, preferably 1-1.5 hours; (c) The antimony element is doped by a doping device so as to be added into the silicon raw material; (d) The antimony element is doped by the gas phase to be added to the silicon feedstock.
  18. 18. A silicon wafer characterized by being produced from the single crystal silicon rod according to any one of claims 1 to 10 or the single crystal silicon rod produced by the production method according to any one of claims 11 to 17; the silicon wafer contains a III-V element and a hydrogen element, wherein the concentration of the III-V element is 1E+14cm -3 to 8E+15cm -3 , the concentration of the hydrogen element is 2E+13cm -3 to 1E+17cm -3 , or The concentration of the III-V element is 2E+14cm -3 to 7E+15cm -3 , the concentration of the hydrogen element is 1E+15cm -3 to 7E+16cm -3 , or The concentration of the group III element is 1E+15cm -3 to 7E+15cm -3 , and the concentration of the hydrogen element is 3E+15cm -3 to 6E+16cm -3 .
  19. 19. A solar cell comprising a silicon substrate prepared from the silicon wafer of claim 19; wherein the resistivity of the silicon substrate is 0.5-3 omega cm, and the thickness is 120-160 mu m.
  20. 20. The solar cell of claim 19, wherein the silicon substrate comprises a doped region, the doped region being doped with a hydrogen element and a group iii-v element; the concentration of hydrogen element in the doped region is 2E+13cm -3 ～1E+17cm -3 ; The concentration of the III-V element in the doped region is 1E+14cm -3 ～8E+15cm -3 .

Description

Monocrystalline silicon rod, preparation method thereof, silicon wafer and solar cell The present application claims priority from China patent office, application No. 202411590218.7, application name "a single crystal silicon rod and its preparation method, silicon wafer and battery" filed on 11 and 08 of 2024, the entire contents of which are incorporated herein by reference. Technical Field The application belongs to the technical field of semiconductors, and particularly relates to a monocrystalline silicon rod, a preparation method thereof, a silicon wafer and a solar cell. Background In photovoltaic cells, monocrystalline silicon rods are used as core materials, and the performance of the monocrystalline silicon rods directly influences the efficiency and stability of the photovoltaic module. However, in the current production process of the single crystal silicon rod, the uniformity of the distribution of doped elements in different positions from the head to the tail of the single crystal silicon rod formed by drawing is poor due to the influences of raw materials and auxiliary materials and the crystal pulling process, so that the change degree of the resistivity of each part in the single crystal silicon rod is not uniform, the single crystal silicon rod is subjected to the influences of the doping process, growth defects can be caused in the growth process of the single crystal silicon rod, and the performance of a photovoltaic cell can be influenced seriously. Disclosure of Invention The application aims to provide a monocrystalline silicon rod, a preparation method thereof, a silicon wafer and a solar cell, and the uniformity of the resistivity of the monocrystalline silicon rod is improved by doping elements influencing the quantity of monocrystalline impurities at the same time. The embodiment of the application provides a single crystal silicon rod, which comprises a head part and a tail part which are opposite along the length direction, wherein the single crystal silicon rod is divided into N sections of silicon rod units from the head part to the tail part, the silicon rod units are provided with a first end and a second end which are opposite along the length direction, the single crystal silicon rod contains III-V elements and hydrogen elements, and the single crystal silicon rod meets the following conditions: K 1＝1-((Cn-1-C Hydrogen gas )/(Cn-C Hydrogen gas )), and 1E-3 is less than or equal to |K 1 is less than or equal to 1E-2; Wherein C Hydrogen gas represents the hydrogen element concentration per unit volume of the single crystal silicon rod, C n represents the III-V element concentration per unit volume of the silicon rod unit of the nth section at the second end, C n-1 represents the III-V element concentration per unit volume of the silicon rod unit of the nth section at the first end, and n is an integer greater than or equal to 1. In some embodiments, the dimensions of any of the N-segment silicon rod units in the length direction are equal to each other. In some embodiments, the dimension of any of the N segments of silicon rod units in the length direction is A mm, 1≤A≤50, and/or And N is an integer greater than or equal to 1 and less than or equal to 6000. In some embodiments, the concentration of hydrogen element per unit volume C Hydrogen gas in the single crystal silicon rod satisfies 2E+13cm -3≤C Hydrogen gas ≤1E+17cm-3. In some embodiments, the concentration of hydrogen element per unit volume C Hydrogen gas in the single crystal silicon rod satisfies 1E+15cm -3≤C Hydrogen gas ≤7E+16cm-3. In some embodiments, the concentration of hydrogen element per unit volume C Hydrogen gas in the single crystal silicon rod satisfies 3E+15cm -3≤C Hydrogen gas ≤6E+16cm-3. In some embodiments, the group III element concentration C n per unit volume of the nth segment silicon rod unit at the second end satisfies 1E+14cm -3≤Cn≤8E+15cm-3. In some embodiments, the group III element concentration per unit volume C n of the nth segment silicon rod unit at the second end satisfies 2E+14cm -3≤Cn≤7E+15cm-3. In some embodiments, the group III element concentration C n per unit volume of the nth stage silicon rod unit at the second end satisfies 1E+15cm -3≤Cn≤7E+15cm-3. In some embodiments, the group III element concentration per unit volume C n-1 of the nth segment silicon rod unit at the first end satisfies 1E+14cm -3≤Cn≤8E+15cm-3. In some embodiments, the group III element concentration per unit volume C n-1 of the nth segment silicon rod unit at the first end satisfies 2E+14cm -3≤Cn≤7E+15cm-3. In some embodiments, the group III element concentration per unit volume C n-1 of the nth segment silicon rod unit at the first end satisfies 1E+15cm -3≤Cn≤7E+15cm-3. In some embodiments, the actual effective segregation coefficient of the group iii element of the single crystal silicon rod is K Effective and effective , which satisfies: K Effective and effective ＝K0/(K0+(1-K0)×EXP((-1)×(V/6