CN-121992498-A - Monocrystalline silicon rod, preparation method thereof, silicon wafer and solar cell

CN121992498ACN 121992498 ACN121992498 ACN 121992498ACN-121992498-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 monocrystalline silicon rod contains antimony element and hydrogen element, the doping concentration of the antimony element in the monocrystalline silicon rod is C a , and the doping concentration of the hydrogen element in the monocrystalline silicon rod is C b , so that the condition that C a /C b is more than or equal to 1E-3 and less than or equal to 4E+2 is satisfied. According to the monocrystalline silicon rod, as antimony and hydrogen are doped at the same time, the effective segregation coefficient of antimony in crystalline silicon is improved through the interaction of hydrogen and antimony, so that the uniformity of resistivity change of the monocrystalline silicon rod is improved, the oxygen content and the service life of the monocrystalline silicon rod are improved, the resistivity is accurately controlled, the resistivity of the monocrystalline silicon rod and derivative products thereof is more uniform and concentrated, and the performance and the production efficiency of Czochralski silicon single crystal silicon and batteries can be effectively improved.

Inventors

ZHANG WENXIA
GAO SHENGJUN
WANG LIN
GUO QIAN
WANG KAI
GUO ZHIRONG
LIANG SHIJIE
ZHOU JIANHUI
LIU JUNMEI
MA XIAOCHEN

Assignees

内蒙古中环晶体材料有限公司

Dates

Publication Date: 20260508
Application Date: 20250430
Priority Date: 20241108

Claims (20)

1. A single crystal silicon rod is characterized in that the single crystal silicon rod contains antimony element and hydrogen element, the doping concentration of the antimony element in the single crystal silicon rod is C a , the doping concentration of the hydrogen element in the single crystal silicon rod is C b , and the conditions that C a /C b is more than or equal to 1E-3 and less than or equal to 4E+2, and preferably C a /C b is more than or equal to 2.5E-1 and less than or equal to 3.5E+2 are satisfied.
2. A single crystal silicon rod according to claim 1, wherein the doping concentration C a of the antimony element in the single crystal silicon rod satisfies 1E+14cm -3 ≤C a ≤8E+15cm -3 , or The doping concentration C a of the antimony element in the single crystal silicon rod is 2E+14cm -3 ≤C a ≤7E+15cm -3 , or The doping concentration C a of the antimony element in the single crystal silicon rod meets 1E+15cm -3 ≤C a ≤7E+15cm -3 .
3. A single crystal silicon rod according to claim 1, wherein the doping concentration C b of the hydrogen element in the single crystal silicon rod satisfies 2E+13cm -3 ≤C b ≤1E+17cm -3 , or The doping concentration C b of the hydrogen element in the single crystal silicon rod is 1E+15cm -3 ≤C b ≤7E+16cm -3 , or The doping concentration C b of the hydrogen element in the single crystal silicon rod meets 3E+15cm -3 ≤C b ≤6E+16cm -3 .
4. The single crystal silicon rod according to claim 1, wherein the single crystal silicon rod has a length direction, the single crystal silicon rod comprises a head part and a tail part which are oppositely arranged along the length direction, the doping concentration of the antimony element at the head part is C a1 , the doping concentration of the antimony element at the tail part is C a2 , and the requirement that 0≤|C a1 -C a2 |/C a2 ≤0.8 is satisfied.
5. The single crystal silicon rod according to claim 4, wherein the single crystal silicon rod has a longitudinal direction, the single crystal silicon rod comprises a head portion and a tail portion which are arranged opposite to each other along the longitudinal direction, the doping concentration of the hydrogen element at the head portion is C b1 , the doping concentration of the hydrogen element at the tail portion is C b2 , and the conditions that 0≤|C b1 -C b2 |/C b2 ≤0.8 are satisfied.
6. A single crystal silicon rod according to claim 5, wherein the doping concentration C a1 of the antimony element at the head portion satisfies 2E+14cm -3 ≤C a1 ≤8E+15cm -3 , or The doping concentration C a2 of the antimony element at the tail part is 1E+14cm -3 ≤C a2 ≤7E+15cm -3 or The doping concentration C b1 of the hydrogen element at the head part satisfies 2E+13cm -3 ≤C b1 ≤1E+17cm -3 , or The doping concentration C b2 of the hydrogen element at the tail part meets 2E+13cm -3 ≤C b1 ≤1E+17cm -3 .
7. The single crystal silicon rod of claim 1, wherein the single crystal silicon rod has a length direction, the single crystal silicon rod comprises a head and a tail which are oppositely arranged along the length direction, the single crystal silicon rod is divided into N sections of silicon rod units from the head to the tail, the silicon rod units comprise a first end and a second end which are oppositely arranged along the length direction, the first end is close to the head, and the second end is close to the tail, the single crystal silicon rod further satisfies that 0≤C n-1 -C n |/C n is less than or equal to 0.8; Wherein C n represents the doping concentration of the antimony element in the second end of the nth section silicon rod unit, C n-1 represents the doping concentration of the antimony element in the first end of the nth section silicon rod unit, and n is an integer greater than or equal to 2.
8. The single crystal silicon rod of claim 7, wherein the single crystal silicon rod has a length direction, the single crystal silicon rod comprises a head and a tail which are oppositely arranged along the length direction, the single crystal silicon rod is divided into S-section silicon rod units from the head to the tail, the silicon rod units comprise a first end and a second end which are oppositely arranged along the length direction, the first end is close to the head, and the second end is close to the tail, the single crystal silicon rod further satisfies that 0≤C s-1 -C s |/C s is less than or equal to 0.8; Wherein C s represents the doping concentration of hydrogen element in the s-th section silicon rod unit at the second end, C s-1 represents the doping concentration of antimony element in the s-th section silicon rod unit at the first end, and n is an integer greater than or equal to 2.
9. A single crystal silicon rod as defined in claim 8 wherein the dimensions of any of said n-segment silicon rod units in said 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 Amm, 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 of 2 or more and 3000 or less.
10. The single crystal silicon rod of claim 8, wherein the single crystal silicon rod meets at least one of the following characteristics: 1)1E+14cm -3 ≤C n ≤8E+15cm -3 ; 2)1E+14cm -3 ≤C n-1 ≤8E+15cm -3 ; 3)2E+13cm -3 ≤C s ≤1E+17cm -3 ; 4)2E+13cm -3 ≤C s-1 ≤1E+17cm -3 。
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 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 antimony element to meet the following conditions: 1E-3≤C a /C b ≤4E+2; Wherein C a is the doping concentration of the antimony element in the single crystal silicon rod, and C b is the doping concentration of the hydrogen element in the single crystal silicon rod.
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. 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. 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. The method for producing a single crystal silicon rod according to claim 11, wherein the volatilization rate η of the antimony element is controlled to satisfy the following conditions before the re-casting step is ended and the isodiametric step is started: 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. 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. The method for producing a single crystal silicon rod according to claim 16, wherein the guide cylinder has a maximum diameter D max , satisfying: D max ≥2W 1 +W 2 ; The first section and the second section are enclosed to form a containing cavity, one end of the containing cavity, which is close to the liquid level of the silicon liquid, is provided with a through hole, and W 2 is the maximum size of the through hole along the first direction, and the unit is mm.
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 antimony element and hydrogen element, wherein the concentration of the antimony 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 antimony 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 antimony 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. A solar cell comprising a silicon substrate prepared from the silicon wafer of claim 18; wherein the resistivity of the silicon substrate is 0.5-3 omega cm, and the thickness of the silicon substrate is 120-160 mu m.
20. The solar cell of claim 19, wherein the silicon substrate comprises a doped region, the doped region being doped with elemental hydrogen and elemental antimony; the concentration of hydrogen element in the doped region is 2E+13cm -3 ～1E+17cm -3 ; The concentration of antimony 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. 202411590194.5, 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, the performance of a single crystal silicon rod as a core material directly affects the efficiency and stability of the photovoltaic cell. However, at present, in the production process of single crystal silicon rods, only a single element is doped, although the oxygen content and the service life of the silicon wafer can be improved and the control of the resistivity can be realized. However, as the resistivity range of a single doping element depends on the segregation coefficient of the element, the uniformity of the doped element distribution is poor in different positions from the head to the tail of the single crystal silicon rod formed by drawing, so that the resistivity variation degree of each part in the single crystal silicon rod is not uniform, and the performance of a photovoltaic cell can be influenced when serious. 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 resistivity change of the monocrystalline silicon rod is improved by doping antimony element and hydrogen element simultaneously. The embodiment of the application provides a monocrystalline silicon rod, which contains antimony element and hydrogen element, wherein the doping concentration of the antimony element in the monocrystalline silicon rod is C a, and the doping concentration of the hydrogen element in the monocrystalline silicon rod is C b, so that the condition that C a/Cb is more than or equal to 1E-3 and less than or equal to 4E+2 is satisfied. In some embodiments, the single crystal silicon rod further satisfies 2.5E-1. Ltoreq.C a/Cb. Ltoreq.3.5E+2. In some embodiments, the doping concentration C a of the antimony element in the single crystal silicon rod satisfies 1E+14cm -3≤Ca≤8E+15cm-3. In some embodiments, the doping concentration C a of the antimony element in the single crystal silicon rod satisfies 2E+14cm -3≤Ca≤7E+15cm-3. In some embodiments, the doping concentration C a of the antimony element in the single crystal silicon rod satisfies 1E+15cm -3≤Ca≤7E+15cm-3. In some embodiments, the doping concentration C b of the hydrogen element in the single crystal silicon rod satisfies 2E+13cm -3≤Cb≤1E+17cm-3. In some embodiments, the doping concentration C b of the hydrogen element in the single crystal silicon rod satisfies 1E+15cm -3≤Cb≤7E+16cm-3. In some embodiments, the doping concentration C b of the hydrogen element in the single crystal silicon rod satisfies 3E+15cm -3≤Cb≤6E+16cm-3. In some embodiments, the single crystal silicon rod has a length direction, the single crystal silicon rod comprises a head part and a tail part which are oppositely arranged along the length direction, the doping concentration of the antimony element at the head part is C a1, the doping concentration of the antimony element at the tail part is C a2, and the conditions that 0≤C a1-Ca2|/Ca2≤0.8 are satisfied. In some embodiments, the single crystal silicon rod has a length direction, the single crystal silicon rod comprises a head part and a tail part which are oppositely arranged along the length direction, the doping concentration of the hydrogen element at the head part is C b1, the doping concentration of the hydrogen element at the tail part is C b2, and the conditions that 0≤C b1-Cb2|/Cb2≤0.8 are satisfied. In some embodiments, the doping concentration C a1 of the antimony element at the head satisfies 2E+14cm -3≤Ca1≤8E+15cm-3. In some embodiments, the doping concentration C a2 of the antimony element at the tail satisfies 1E+14cm -3≤Ca2≤7E+15cm-3. In some embodiments, the doping concentration C b1 of the hydrogen element at the head portion satisfies 2E+13cm -3≤Cb1≤1E+17cm-3. In some embodiments, the doping concentration C b2 of the hydrogen element at the tail portion satisfies 2E+13cm -3≤Cb1≤1E+17cm-3. In some embodiments, the single crystal silicon rod has a length direction, the single crystal silicon rod comprises a head and a tail which are oppositely arranged along the length direction, the single crystal silicon rod is divided into N sections of silicon rod units from the head to the tail, the silicon rod units comprise a first end and a second end which are opposite along the length direction, the first end is close to the head, and the second end is close to the tail; Wherein C n represent