Monocrystalline silicon rod and preparation method thereof, silicon wafer and solar cell

Abstract

The invention discloses a silicon single crystal rod and 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 in 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, and each silicon rod unit is provided with a first end and a second end which are opposite in the length direction; the single crystal silicon rod contains at least one of III-V elements and a hydrogen element; the single crystal silicon rod satisfies the following conditions: K1 = 1-((Cn-1-C hydrogen) / (Cn-C hydrogen)), and K1 is more than or equal to 1E-3 and less than or equal to 1E-2. According to the silicon single crystal rod, the III-V element and the hydrogen element are doped at the same time, and the effective segregation coefficient of the III-V element dopant in crystalline silicon in silicon is improved through the interaction of hydrogen and the III-V element, so that the resistivity consistency of the silicon rod is improved.

Description

[0001] This application claims priority to Chinese Patent Application No. 202411590218.7, filed on November 8, 2024, entitled "A Single Crystal Silicon Rod and its Preparation Method, Silicon Wafer and Battery", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application belongs to the field of semiconductor technology, specifically relating to a single-crystal silicon rod and its preparation method, a silicon wafer, and a solar cell. Background Technology

[0003] In photovoltaic cells, monocrystalline silicon rods are the core material, and their performance directly affects the efficiency and stability of photovoltaic modules. However, in the current production process of monocrystalline silicon rods, the distribution of doped elements is poor from head to tail due to the influence of raw materials and crystal pulling processes. This results in inconsistent resistivity variations throughout the monocrystalline silicon rod, and the doping process can also lead to growth defects during the growth of the monocrystalline silicon rod, which can severely affect the performance of photovoltaic cells. Summary of the Invention

[0004] The purpose of this application is to provide a monocrystalline silicon rod and its preparation method, a silicon wafer and a solar cell, which improves the resistivity uniformity of the monocrystalline silicon rod by simultaneously doping with elements that affect the number of impurities in the monocrystalline silicon.

[0005] This application provides a single-crystal silicon rod, which includes a head and a tail opposite each other along its length. From the head to the tail, the single-crystal silicon rod is divided into N silicon rod units, each silicon rod unit having a first end and a second end opposite each other along its length. The single-crystal silicon rod contains a group III-V element and hydrogen. The single-crystal silicon rod satisfies the following:

[0006] K1=1-((C n-1 -C 氢 ) / (C n -C 氢 And 1E-3≤|K1|≤1E-2;

[0007] Among them, C 氢 This indicates the hydrogen concentration per unit volume of the single-crystal silicon rod; C n C represents the concentration of Group III-V elements per unit volume at the second end of the nth silicon rod unit; n-1 This represents the concentration of Group III-V elements per unit volume at the first end of the nth silicon rod unit; n is an integer greater than or equal to 1.

[0008] In some embodiments, any one of the N silicon rod units has the same dimension in the length direction.

[0009] In some embodiments, the dimension of any one of the N silicon rod units in the length direction is A mm, satisfying: 1 ≤ A ≤ 50; and / or

[0010] N is an integer greater than or equal to 1 and less than or equal to 6000.

[0011] In some embodiments, the hydrogen concentration C per unit volume in the single-crystal silicon rod 氢 Satisfy: 2E+13cm -3 ≤C 氢 ≤1E+17cm -3 .

[0012] In some embodiments, the hydrogen concentration C per unit volume in the single-crystal silicon rod 氢 Satisfy: 1E+15cm -3 ≤C 氢 ≤7E+16cm -3 .

[0013] In some embodiments, the hydrogen concentration C per unit volume in the single-crystal silicon rod 氢 Satisfying: 3E+15cm -3 ≤C 氢 ≤6E+16cm -3 .

[0014] In some embodiments, the concentration C of group III-V elements per unit volume at the second end of the silicon rod unit in the nth segment is... n Satisfy: 1E+14cm -3 ≤C n ≤8E+15cm -3 .

[0015] In some embodiments, the concentration C of group III-V elements per unit volume at the second end of the silicon rod unit in the nth segment is... n Satisfy: 2E+14cm -3 ≤C n ≤7E+15cm -3 .

[0016] In some embodiments, the concentration C of group III-V elements per unit volume at the second end of the silicon rod unit in the nth segment is... n Satisfy: 1E+15cm -3 ≤C n ≤7E+15cm -3 .

[0017] In some embodiments, the concentration of Group III-V elements per unit volume C at the first end of the nth silicon rod unit is... n-1 Satisfy: 1E+14cm -3 ≤Cn ≤8E+15cm -3 .

[0018] In some embodiments, the concentration of Group III-V elements per unit volume C at the first end of the nth silicon rod unit is... n-1 Satisfy: 2E+14cm -3 ≤C n ≤7E+15cm -3 .

[0019] In some embodiments, the concentration of Group III-V elements per unit volume C at the first end of the nth silicon rod unit is... n-1 Satisfy: 1E+15cm -3 ≤C n ≤7E+15cm -3 .

[0020] In some embodiments, the actual effective segregation coefficient of the group III-V elements in the single-crystal silicon rod is K. 有效 ,satisfy:

[0021] K 有效 =K0 / (K0+(1-K0)×EXP((-1)×(V / 600)×δ / (10×D)))×(1-K1);

[0022] Wherein, K0 is the original effective segregation coefficient of group III-V elements in single-crystal silicon rods; V represents the crystal pulling speed in mm / min; δ represents the boundary layer thickness in mm; D is the diffusion coefficient in cm; and K1 represents the correction coefficient after the combined effect of hydrogen and group III-V elements.

[0023] In some embodiments, the boundary layer thickness δ ranges from 0.005 to 0.05 mm.

[0024] In some embodiments, the crystal pulling speed V ranges from 1.1 to 2.2 mm / min.

[0025] In some embodiments, the diffusion coefficient D ranges from 0.0001 to 0.001 cm.

[0026] In some embodiments, the actual effective segregation coefficient K of the group III-V elements in the single-crystal silicon rod 有效 Further satisfying: 0.005 ≤ K 有效 ≤0.03.

[0027] In some embodiments, the actual effective segregation coefficient K of the group III-V elements in the single-crystal silicon rod 有效 Further satisfy:

[0028] 0.005≤K 有效 ≤0.028.

[0029] In some embodiments, the actual effective segregation coefficient K of the group III-V elements in the single-crystal silicon rod 有效 Further satisfy:

[0030] 0.005≤K 有效 ≤0.018.

[0031] In some embodiments, the resistivity of the single-crystal silicon rod is ρΩ·cm, satisfying: 0.1≤ρ≤7.

[0032] In some embodiments, the resistivity of the single-crystal silicon rod is ρΩ·cm, satisfying: 0.4≤ρ≤1.5.

[0033] In some embodiments, the resistivity of the single-crystal silicon rod is ρΩ·cm, satisfying: 0.6≤ρ≤1.5.

[0034] In some embodiments, the resistivity of the single-crystal silicon rod is ρΩ·cm, satisfying: 0.8≤ρ≤1.4.

[0035] In some embodiments, the group III-V elements are selected from at least one of antimony, phosphorus, gallium, boron, and arsenic.

[0036] In some embodiments, this application also provides a silicon wafer prepared from the aforementioned single-crystal silicon rod; the silicon wafer contains at least one of group III-V elements and hydrogen; wherein the concentration of the group III-V elements is 1E+14cm⁻¹. -3 Up to 8E+15cm -3 The concentration of hydrogen is 2E+13cm. -3 Up to 1E+17cm -3 .

[0037] In some embodiments, the concentration of the group III-V elements is 2E+14cm⁻¹. -3 Up to 7E+15cm -3 The concentration of hydrogen is 1E+15cm. -3 Up to 7E+16cm -3 .

[0038] In some embodiments, the concentration of the group III-V elements is 1E+15cm⁻¹. -3 Up to 7E+15cm -3 The concentration of hydrogen is 3E+15cm. -3 Up to 6E+16cm -3 .

[0039] In some embodiments, this application also provides a method for preparing a single-crystal silicon rod, comprising:

[0040] A silicon raw material is provided, and a single crystal silicon rod is obtained through the steps of material preparation, repeated feeding, temperature stabilization, crystal pulling, shoulder formation, equal diameter formation, and finishing. In at least one of the steps of material preparation, repeated feeding, temperature stabilization, crystal pulling, shoulder formation, equal diameter formation, and finishing, hydrogen gas is introduced into the silicon raw material. Before the equal diameter formation step, a raw material containing group III-V elements is added to the silicon raw material.

[0041] Specifically, before the single-crystal silicon rod is fully grown, the doping concentration during the solidification process of the single-crystal silicon rod is adjusted to control the doping ratio of hydrogen and the group III-V elements to meet the following requirements:

[0042] K1=1-((C n-1 -C 氢 ) / (C n -C 氢 And 1E-3≤|K1|≤1E-2;

[0043] In the formula, C 氢 This indicates the hydrogen concentration per unit volume of the single-crystal silicon rod; C n C represents the concentration of Group III-V elements per unit volume at the second end of the nth silicon rod unit; n-1 This represents the concentration of Group III-V elements per unit volume at the first end of the nth silicon rod unit; n is an integer greater than or equal to 1.

[0044] In some embodiments, the time for introducing hydrogen gas into the silicon raw material satisfies:

[0045] t 总 =t1+t2+t3+t4+t5+t6+t7, and 0.5h≤t 总 ≤60h;

[0046] Among them, t 总 The total time for introducing hydrogen is t1, which is the time for introducing hydrogen during the material preparation stage; t2 is the time for introducing hydrogen during the re-feeding stage; t3 is the time for introducing hydrogen during the temperature stabilization stage; t4 is the time for introducing hydrogen during the crystallization stage; t5 is the time for introducing hydrogen during the shoulder formation stage; t6 is the time for introducing hydrogen during the equal diameter stage; and t7 is the time for introducing hydrogen during the finishing stage.

[0047] In some embodiments, the time for introducing hydrogen gas into the silicon raw material also satisfies:

[0048] t1: t2: t3: t4: t5: t6: t7=(0~10): (0~8): (0~2): (0~1.5): (0~3):

[0049] (0~55): (0~2).

[0050] In some embodiments, the method for preparing a single-crystal silicon rod further includes: after the re-feeding step, introducing a protective gas into the silicon raw material;

[0051] The hydrogen gas and the protective gas form a mixed gas, wherein the volume percentage of the hydrogen gas in the mixed gas is 1-90%, preferably 5-90%.

[0052] In some embodiments, the flow rate of the hydrogen gas is 0.0001 to 180 slpm.

[0053] In some embodiments, the flow rate of the protective gas is 40 to 200 slpm.

[0054] In some embodiments, before the end of the re-addition step and the beginning of the isodiameter step, the volatilization rate η of the group III-V elements is controlled to satisfy:

[0055] η=(H1 / 100mm)×100%-15%;

[0056] Wherein, H1 is the liquid outlet distance in the single crystal furnace, in mm; the volatility η satisfies: 5% ≤ η ≤ 25%; the liquid outlet distance H1 satisfies: 20mm ≤ H1 ≤ 40mm.

[0057] In some embodiments, a flow guide tube is provided inside the single crystal furnace, the flow guide tube comprising a first section and a second section connected to each other, satisfying the following:

[0058] tanα = H2 / W1, and 0 ≤ tanα ≤ 0.58;

[0059] Where α is the angle formed by the second segment and the first direction, in °; H2 is the height of the projection of the second segment in the second direction, in mm; W1 is the length of the projection of the second segment in the first direction, in mm; and the first direction and the second direction intersect.

[0060] In some embodiments, the step of adjusting the doping concentration during the solidification process of the single-crystal silicon rod further includes at least one of the following conditions:

[0061] (a) Adding an antimony-containing raw material and a phosphorus-containing raw material to the silicon raw material, wherein the mass ratio of the silicon raw material to the antimony-containing raw material and the phosphorus-containing raw material is 1000:(0.05~0.5):(0.005~0.05);

[0062] (b) The temperature range of the temperature stabilization stage is controlled to be 1450-1500°C, and the time is 1-2 hours, preferably 1-1.5 hours;

[0063] (c) The antimony element is doped using a doping device to be added to the silicon raw material;

[0064] (d) The antimony element is added to the silicon raw material by gas-phase doping.

[0065] In some embodiments, this application also provides a silicon wafer prepared from a single-crystal silicon rod as described in any of the above embodiments; the silicon wafer contains group III-V elements and hydrogen; wherein the concentration of the group III-V elements is 1E+14cm⁻¹. -3 Up to 8E+15cm -3 The concentration of hydrogen is 2E+13cm. -3 Up to 1E+17cm -3 .

[0066] In some embodiments, the concentration of the group III-V elements is 2E+14cm⁻¹. -3 Up to 7E+15cm -3 The concentration of hydrogen is 1E+15cm. -3 Up to 7E+16cm -3 .

[0067] In some embodiments, the concentration of the group III-V elements is 1E+15cm⁻¹. -3 Up to 7E+15cm -3 The concentration of hydrogen is 3E+15cm. -3 Up to 6E+16cm -3 .

[0068] In some embodiments, this application also provides a solar cell, including a silicon substrate, said silicon substrate being prepared from the silicon wafer described in the above embodiments;

[0069] The resistivity of the silicon substrate is 0.5-3 ΩΩcm, and the thickness is 120-160 μm.

[0070] In some embodiments, the silicon substrate includes a doped region doped with hydrogen and group III-V elements;

[0071] The hydrogen concentration in the doped region is 2E+13cm⁻¹ -3 ~1E+17cm -3 ;

[0072] The concentration of Group III-V elements in the doped region is 1E+14cm⁻¹ -3 ~8E+15cm -3 .

[0073] The beneficial effects of this application are as follows: Compared with the prior art, the monocrystalline silicon rod provided in this application, due to the simultaneous doping of group III-V elements and hydrogen, improves the effective segregation coefficient of group III-V element dopants in crystalline silicon through the interaction of hydrogen and group III-V elements, thereby enhancing the resistivity uniformity of the silicon rod. Simultaneously, hydrogen and group III-V elements can influence the number of impurities in the monocrystalline silicon, and their addition can further ensure that the resistivity meets the design requirements of different ranges, without being limited by the segregation coefficient of a single element. This can improve the oxygen content and lifetime of the monocrystalline silicon rod and achieve precise resistivity control, making the resistivity of the monocrystalline silicon rod and its derivatives more uniform and concentrated, and effectively improving the performance and production efficiency of Czochralski-grown monocrystalline silicon and cells. It should be noted that the silicon wafer, monocrystalline silicon rod preparation method, and cell of the embodiments of this application can include all the technical features and beneficial effects of the aforementioned monocrystalline silicon rod, which will not be repeated here. Attached Figure Description

[0074] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0075] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0076] Figure 1 This is a schematic diagram of the structure of a single crystal furnace provided in an embodiment of this application;

[0077] Figure 2 for Figure 1 A magnified view of part A in the middle;

[0078] Figure 3 A top view of the top cover of a single crystal furnace provided in an embodiment of this application;

[0079] Figure 4 This is a schematic diagram of the structure of a gas flow region inside a single crystal furnace, provided in an embodiment of this application.

[0080] Figure 5 This is a schematic diagram of a single-crystal silicon rod divided into N silicon rod units, as provided in an embodiment of this application.

[0081] Explanation of reference numerals in the attached figures:

[0082] 10-Guide tube, 11-First section, 12-Second section, 13-Containing cavity, 14-Through hole, 20-Top cover, 21-First vent hole, 22-Second vent hole, 30-Crucible, 40-Silicon liquid, 50-First gas flow area, 60-Second gas flow area, 61-First area, 62-Second area, 100-Single crystal furnace. Detailed Implementation

[0083] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0084] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for mutual communication; they can refer to a direct connection, an indirect connection through an intermediate medium, or an indirect connection through a pipe or conduit; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically limited. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0085] This application provides a single-crystal silicon rod, such as... Figure 5 As shown, a single-crystal silicon rod includes a head and a tail opposite each other along its length. From the head to the tail, the single-crystal silicon rod is divided into N silicon rod units, each silicon rod unit having a first end and a second end opposite each other along its length. The single-crystal silicon rod contains group III-V elements and hydrogen. The single-crystal silicon rod satisfies the following:

[0086] K1=1-((C n-1 -C 氢 ) / (C n -C 氢 And 1E-3≤|K1|≤1E-2;

[0087] Among them, C 氢 This indicates the hydrogen concentration per unit volume of a single-crystal silicon rod; C nC represents the concentration of Group III-V elements per unit volume at the second end of the nth silicon rod unit; n-1 This represents the concentration of Group III-V elements per unit volume at the first end of the nth silicon rod unit; n is an integer greater than or equal to 1. It is understood that n ≤ N.

[0088] It is understood that the single-crystal silicon rod provided in this embodiment is doped with both group III-V elements and hydrogen. Through the interaction between hydrogen and group III-V elements, the effective segregation coefficient of group III-V element dopants in crystalline silicon is improved. When the range of 1E-3≤|K1|≤1E-2 is met, the oxygen content and lifetime of the single-crystal silicon rod can be improved and the resistivity can be precisely controlled, making the resistivity of the single-crystal silicon rod and its derivatives more uniform and concentrated, thereby improving the resistivity consistency of the silicon rod.

[0089] In some embodiments, the value of N is based on the actual length of the monocrystalline silicon rod. For example, when N is 1, the monocrystalline silicon rod is a single segment, with the first end corresponding to the head position and the second end corresponding to the tail position. Of course, when N is an integer greater than 1, the monocrystalline silicon rod is divided into at least two segments, with the head of each segment corresponding to the first end position and the tail of each segment corresponding to the second end position.

[0090] In some embodiments, any one of the N silicon rod units has the same dimensions along its length. It is understood that when the dimensions are equal, each silicon rod unit can be considered as having the same unit structure, and therefore the uniformity of doping with group III-V elements and hydrogen in each silicon rod unit can be determined by the value of K1.

[0091] In some embodiments, the dimension of any one of the N silicon rod units in the length direction is A mm, satisfying: 1 ≤ A ≤ 50. For example, A can be any one value or a range between any two values ​​from 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, and 50 mm. The length of a silicon rod unit is determined by the overall length of the single-crystal silicon rod and the number of segments that need to be divided.

[0092] Furthermore, the preferred dimension Amm can be in the range of 5mm to 20mm; the more preferred dimension Amm can be in the range of 10mm to 15mm.

[0093] In some embodiments, n is an integer greater than or equal to 1 and less than or equal to 6000, and N is an integer greater than or equal to 1 and less than or equal to 6000. In some other embodiments, n is an integer greater than or equal to 1 and less than or equal to 120, and N is an integer greater than or equal to 1 and less than or equal to 120. For example, taking a single-crystal silicon rod with a total length of 6000mm as an example, when it needs to be divided into 1 segment, N is 6000, and when it needs to be divided into 50 segments, N is 120; similarly, the total length of the single-crystal silicon rod can also be any one of 5000mm, 4000mm, 3000mm, 2000mm, 1000mm, 500mm, or a range between any two.

[0094] In some embodiments, more preferably, n is an integer greater than or equal to 5 and less than or equal to 1000, and N is an integer greater than or equal to 5 and less than or equal to 1000. In some other embodiments, n is an integer greater than or equal to 10 and less than or equal to 500, and N is an integer greater than or equal to 10 and less than or equal to 500.

[0095] In some embodiments, the hydrogen concentration C per unit volume in a single-crystal silicon rod 氢 Satisfy: 2E+13cm -3 ≤C 氢 ≤1E+17cm -3 When C 氢 When the above ranges are met, interactions with group III-V elements can be achieved, improving the effective segregation coefficient of group III-V elements in crystalline silicon and thus enhancing the resistivity uniformity of single-crystal silicon. Simultaneously, hydrogen doping in silicon can introduce additional electrons, forming chemical bonds between hydrogen atoms and silicon. These additional electrons can increase the conductivity of silicon materials, thereby reducing resistivity. Hydrogen can also interact with impurities or defects in silicon materials, reducing interference from impurities or defects on electron transport and further improving conductivity and resistivity uniformity. Furthermore, some hydrogen elements can passivate and attract impurities and defects within silicon crystals, improving the minority carrier lifetime of single-crystal silicon rods and simultaneously regulating the uniformity of radial and axial resistivity distribution in single-crystal silicon rods.

[0096] In some embodiments, the hydrogen concentration C per unit volume in a single-crystal silicon rod 氢 It can be 2E+13cm -3 3E+13cm -3 4E+13cm -3 5E+13cm -3 8E+13cm -31E+14cm -3 2E+14cm -3 5E+14cm -3 8E+14cm -3 1E+15cm -3 2E+15cm -3 5E+15cm -3 8E+15cm -3 1E+16cm -3 5E+16cm -3 6E+16cm -3 7E+16cm -3 1E+17cm -3 The range between any one or any two values ​​in the range.

[0097] In some embodiments, the hydrogen concentration C per unit volume in a single-crystal silicon rod 氢 Satisfy: 1E+15cm -3 ≤C 氢 ≤7E+16cm -3 .

[0098] In some embodiments, the hydrogen concentration C per unit volume in a single-crystal silicon rod 氢 Satisfying: 3E+15cm -3 ≤C 氢 ≤6E+16cm -3 .

[0099] In some embodiments, the concentration C of group III-V elements per unit volume at the second end of the silicon rod unit of the nth segment is... n Satisfy: 1E+14cm -3 ≤C n ≤8E+15cm -3 For example, it could be 1E+14cm -3 2E+14cm -3 3E+14cm -3 4E+14cm -3 5E+14cm -3 6E+14cm -3 7E+14cm -3 8E+14cm -3 9E+14cm -3 1E+15cm -3 2E+15cm -3 3E+15cm -3 4E+15cm -3 5E+15cm -3 6E+15cm -3 7E+15cm-3 8E+15cm -3 The range between any one or any two values ​​in the range.

[0100] In some embodiments, the concentration C of group III-V elements per unit volume at the second end of the silicon rod unit of the nth segment is... n Satisfy: 2E+14cm -3 ≤C n ≤7E+15cm -3 .

[0101] In some embodiments, the concentration C of group III-V elements per unit volume at the second end of the silicon rod unit of the nth segment is... n Satisfy: 1E+15cm -3 ≤C n ≤7E+15cm -3 .

[0102] In some embodiments, the concentration of Group III-V elements per unit volume C at the first end of the nth silicon rod unit is... n-1 Satisfy: 1E+14cm -3 ≤C n ≤8E+15cm -3 For example, it could be 1E+14cm -3 2E+14cm -3 3E+14cm -3 4E+14cm -3 5E+14cm -3 6E+14cm -3 7E+14cm -3 8E+14cm -3 9E+14cm -3 1E+15cm -3 2E+15cm -3 3E+15cm -3 4E+15cm -3 5E+15cm -3 6E+15cm -3 7E+15cm -3 8E+15cm -3 The range between any one or any two values ​​in the range.

[0103] In some embodiments, the concentration of Group III-V elements per unit volume C at the first end of the nth silicon rod unit is... n-1 Satisfy: 2E+14cm -3 ≤C n-1 ≤7E+15cm -3 .

[0104] In some embodiments, the concentration of Group III-V elements per unit volume C at the first end of the nth silicon rod unit is... n-1 Satisfy: 1E+15cm -3 ≤C n-1 ≤7E+15cm -3 .

[0105] It is understandable that when C n Meets 2E+14cm -3 ≤C n ≤7E+15cm -3 , and C n-1 Satisfying 1E+14cm -3 ≤C n ≤8E+15cm -3 Within a certain range, doping silicon rods with group III-V elements can introduce additional electrons or holes, altering the conductivity of the silicon material. These additional charge carriers can increase the conductivity of the silicon material, thereby reducing its resistivity. Simultaneously, the doping of group III-V elements can also interact with hydrogen atoms in the silicon material, forming a complex doping system that further modulates the conductivity and resistivity of the silicon material.

[0106] In some embodiments, the actual effective segregation coefficient of group III-V elements in a single-crystal silicon rod is K. 有效 ,satisfy:

[0107] K 有效 =K0 / (K0+(1-K0)×EXP((-1)×(V / 600)×δ / (10×D)))×(1-K1);

[0108] Where K0 is the original effective segregation coefficient of group III-V elements in single-crystal silicon rods; V represents the crystal pulling speed in mm / min; δ represents the boundary layer thickness in mm; D is the diffusion coefficient in cm; and K1 represents the dimensionless correction coefficient after the combined effect of hydrogen and group III-V elements.

[0109] It is understandable that the actual effective segregation coefficient of group III-V elements in a single-crystal silicon rod is K. 有效 This reflects the degree of selective separation of Group III-V elements in monocrystalline silicon. For example, during the doping of antimony into monocrystalline silicon, the effective segregation coefficient can be used to assess the selectivity between antimony ions and other ions. A higher effective segregation coefficient indicates that antimony ions are more easily adsorbed or separated by monocrystalline silicon, while a lower effective segregation coefficient indicates a lower degree of adsorption or separation of antimony ions from other ions. In this embodiment, since hydrogen and Group III-V elements are doped simultaneously, hydrogen has a certain influence on the effective segregation coefficient when judging the selectivity of Group III-V elements. Therefore, the actual effective segregation coefficient is related to K1, and K1 is used to adjust K... 有效After correction, the resistivity control of single-crystal silicon rods can be made more accurate, with the resistivity control precision within ±5%, which can further improve the performance of silicon rods and their derivatives.

[0110] In some embodiments, the boundary layer thickness δ ranges from 0.005 to 0.05 mm. The boundary layer thickness δ is a parameter of the crystal during the crystallization process.

[0111] In some embodiments, the crystal pulling speed V ranges from 1.1 to 2.2 mm / min.

[0112] In some embodiments, the diffusion coefficient D ranges from 0.0001 to 0.001 cm.

[0113] In some embodiments, the original effective segregation coefficient K0 of group III-V elements in single-crystal silicon rods has different specific values ​​depending on the different group III-V elements. For example, K0 for antimony is 0.023, K0 for phosphorus is 0.35, K0 for gallium is 0.008, K0 for boron is 0.8, and K0 for arsenic is 0.3.

[0114] In some embodiments, the actual effective segregation coefficient K of group III-V elements in a single-crystal silicon rod 有效 Further satisfying: 0.005 ≤ K 有效 ≤0.38.

[0115] In some embodiments, the actual effective segregation coefficient K of group III-V elements in a single-crystal silicon rod 有效 Further satisfying: 0.005 ≤ K 有效 ≤0.03;

[0116] In some embodiments, the actual effective segregation coefficient K of group III-V elements in a single-crystal silicon rod 有效 Further satisfying: 0.005 ≤ K 有效 ≤0.028;

[0117] In some embodiments, the actual effective segregation coefficient K of group III-V elements in a single-crystal silicon rod 有效 Further satisfying: 0.005 ≤ K 有效 ≤0.018.

[0118] It is understandable that the actual effective segregation coefficient K of group III-V elements in a single-crystal silicon rod is... 有效 Within the above range, group III-V elements can be distributed more evenly in silicon rods, thereby further improving the resistivity consistency of silicon rods.

[0119] In some embodiments, the resistivity of the single-crystal silicon rod is ρΩ·cm, satisfying: 0.1≤ρ≤7. For example, ρΩ·cm can be any one value or a range between any two values ​​selected from 0.1Ω·cm, 0.2Ω·cm, 0.3Ω·cm, 0.4Ω·cm, 0.5Ω·cm, 0.8Ω·cm, 1Ω·cm, 1.5Ω·cm, 2Ω·cm, 2.5Ω·cm, 3Ω·cm, 3.5Ω·cm, 4Ω·cm, 4.5Ω·cm, 5Ω·cm, 5.5Ω·cm, 6Ω·cm, 6.5Ω·cm, and 7Ω·cm.

[0120] In some embodiments, the resistivity of the single-crystal silicon rod is ρΩ·cm, satisfying: 0.4≤ρ≤1.5.

[0121] In some embodiments, the resistivity of the single-crystal silicon rod is ρΩ·cm, satisfying: 0.6≤ρ≤1.5.

[0122] In some embodiments, the resistivity of the single-crystal silicon rod is ρΩ·cm, satisfying: 0.8≤ρ≤1.4.

[0123] In some embodiments, the group III-V elements are selected from at least one of antimony, phosphorus, gallium, boron, and arsenic.

[0124] In some embodiments, this application also provides a method for preparing a single-crystal silicon rod, comprising:

[0125] A silicon raw material is provided, and a single crystal silicon rod is obtained through the steps of material preparation, repeated feeding, temperature stabilization, crystal pulling, shoulder formation, equal diameter formation, and finishing. In at least one of the steps of material preparation, repeated feeding, temperature stabilization, crystal pulling, shoulder formation, equal diameter formation, and finishing, hydrogen gas is introduced into the silicon raw material. Before the equal diameter formation step, a raw material containing group III-V elements is added to the silicon raw material.

[0126] Before the single-crystal silicon rod is fully grown, the doping concentration during the solidification process is adjusted to control the doping ratio of hydrogen and group III-V elements to meet the following requirements:

[0127] K1=1-((C n-1 -C 氢 ) / (C n -C 氢 And 1E-3≤|K1|≤1E-2;

[0128] In the formula, C 氢 This indicates the hydrogen concentration per unit volume of a single-crystal silicon rod; C n C represents the concentration of Group III-V elements per unit volume at the second end of the nth silicon rod unit; n-1 This represents the concentration of Group III-V elements per unit volume at the first end of the nth silicon rod unit; n is an integer greater than or equal to 1.

[0129] Understandably, the concentration of doped elements during the solidification process of a single-crystal silicon rod can be adjusted by regulating the time and flow rate of hydrogen gas introduced.

[0130] In some embodiments, the time for introducing hydrogen into the silicon raw material satisfies:

[0131] t 总 =t1+t2+t3+t4+t5+t6+t7, and 0.5h≤t 总 ≤82h;

[0132] Among them, t 总 The total time for introducing hydrogen is t1, which is the time for introducing hydrogen during the material preparation stage; t2 is the time for introducing hydrogen during the re-feeding stage; t3 is the time for introducing hydrogen during the temperature stabilization stage; t4 is the time for introducing hydrogen during the crystallization stage; t5 is the time for introducing hydrogen during the shoulder formation stage; t6 is the time for introducing hydrogen during the equal diameter stage; and t7 is the time for introducing hydrogen during the finishing stage.

[0133] Understandably, t 总 The value of (unit: h) can be any value or a range between any two of the following: 0.5, 1, 2, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82. By controlling the hydrogen introduction time to meet the above value range, the hydrogen doping concentration and doping uniformity can be controlled to an ideal level.

[0134] In some embodiments, the time for introducing hydrogen into the silicon raw material also satisfies:

[0135] t1: t2: t3: t4: t5: t6: t7=(0~10): (0~8): (0~2): (0~1.5): (0~3):

[0136] (0~55): (0~2).

[0137] Specifically, t1, t2, t3, t4, t5, t6, and t7 are not all 0 at the same time. For example, the ratio of t1:t2:t3:t4:t5:t6:t7 can be any value or a range between any two values ​​from 2:2:0:0:0:0:0, 0:2:1.5:1:3:50:2, 1:2:1:0:0:0:0, 0:0:1:1.5:2:55:0, and 0:8:1:1.5:3:10:1.

[0138] In some embodiments, the time for introducing hydrogen into the silicon raw material further satisfies:

[0139] t1: t2: t3: t4: t5: t6: t7= (0.00001~10): (0.00001~8): (0.00001~2):

[0140] (0.00001~1.5): (0.00001~3): (0.00001~55): (0.00001~2).

[0141] In some embodiments, it is preferable to introduce hydrogen into the silicon raw material after the refeeding step is completed.

[0142] Understandably, introducing hydrogen during the temperature stabilization stage allows it to act as a heat transfer medium, making the ambient temperature of the silicon raw material more uniform and stable. This prevents stress caused by localized overheating or undercooling due to temperature fluctuations, reducing the probability of defects in the silicon crystal. In the crystallization stage, introducing hydrogen suppresses impurity adsorption on the surface of the silicon melt, reducing the risk of impurities entering the growing crystal. During the shoulder formation stage, introducing hydrogen can regulate the undercooling of the silicon melt, allowing the crystal to grow at a specific angle and rate, obtaining crystals that meet size requirements, further reducing dislocations and crystal orientation deviations, and ensuring consistent crystal growth. In the constant diameter stage, introducing hydrogen helps maintain a stable growth environment, ensuring that the hydrogen doping concentration within the silicon crystal is radially uniform. When the time for introducing hydrogen into the silicon raw material meets the above-mentioned proportions, the doping concentration and uniformity of hydrogen in the single-crystal silicon rod can be precisely controlled, thereby reducing dislocations and crystal orientation deviations in the single-crystal silicon rod. It also makes the head-to-tail ratio of dislocations and crystal orientation deviations more likely to be 1, significantly improving the quality and production efficiency of single-crystal silicon.

[0143] In some embodiments, the method for preparing a single-crystal silicon rod further includes: after the re-feeding step, introducing a protective gas into the silicon raw material;

[0144] In this mixture, hydrogen and protective gas form a gas mixture, with the volume percentage of hydrogen in the gas mixture ranging from 1% to 90%.

[0145] It is understandable that the volume percentage of hydrogen in the mixed gas can be any value or a range between any two of the following: 1%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%. The protective gas can be argon. Introducing a protective gas simultaneously with hydrogen serves two purposes: firstly, it creates a certain gas flow environment within the single crystal furnace 100, diffusing around the silicon crystal growth area and promoting stable convection, ensuring a consistent crystal growth environment and avoiding crystal defects caused by localized environmental differences; secondly, it transfers heat to areas outside the silicon crystal growth area through gas flow, thus providing cooling and helping to regulate the temperature gradient. Simultaneously, it removes impurities volatilized from the surface of the molten silicon, which is beneficial for crystal growth along a specific direction, reducing crystal orientation deviation and improving the overall quality of the single crystal silicon rod. When the volume percentage of hydrogen in the mixed gas meets the above-mentioned range, it ensures the growth quality of the single crystal silicon rod while performing hydrogen doping on the single crystal silicon, and avoids the risk of explosion caused by excessive hydrogen content.

[0146] In some embodiments, the volume percentage of hydrogen in the gas mixture is preferably 5% to 90%.

[0147] It is understandable that the volume percentage of hydrogen in the gas mixture can be any value or a range between any two values ​​of 5%, 15%, 25%, 35%, 45%, 55%, 65%, 75%, 85%, 90%.

[0148] In some embodiments, the volume percentage of hydrogen in the gas mixture is preferably 5% to 35%.

[0149] It is understandable that the volume percentage of hydrogen in the gas mixture can be any value of 5%, 10%, 15%, 20%, 25%, 30%, or 35%, or any range between two values. When the volume percentage of hydrogen in the gas mixture meets the above range, it can further ensure that sufficient hydrogen is used to dope the single-crystal silicon.

[0150] In some embodiments, the hydrogen flow rate is 0.0001 to 180 slpm.

[0151] It is understandable that the hydrogen flow rate (unit: slpm) can be any value or a range between any two of the following: 0.0001, 1, 30, 60, 90, 120, 150, 180.

[0152] In some embodiments, the hydrogen flow rate is preferably 5 to 50 slpm.

[0153] Understandably, the hydrogen flow rate (unit: slpm) can be any value or a range between any two of the following: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50. When the hydrogen flow rate meets the above range, the hydrogen has an ideal doping concentration in the single-crystal silicon rod, while avoiding uneven distribution caused by excessive real-time flow rate, thus ensuring good uniformity of hydrogen concentration in both the axial and radial directions of the single-crystal silicon rod.

[0154] In some embodiments, the flow rate of the protective gas is 40 to 200 slpm.

[0155] It is understandable that the flow rate of the protective gas (unit: slpm) can be any value or a range between any two of the following: 40, 60, 80, 100, 120, 140, 160, 180, 200.

[0156] In some embodiments, between the end of the re-addition step and the beginning of the isodiameter step, the volatilization rate η of the group III-V elements is controlled to satisfy:

[0157] η=(H1 / 100mm)×100%-15%;

[0158] Where H1 is the liquid outlet distance inside the single crystal furnace 100, in mm; the volatility η satisfies: 5% ≤ η ≤ 25%; the liquid outlet distance H1 satisfies: 20mm ≤ H1 ≤ 40mm.

[0159] like Figure 1 and Figure 2 As shown, the single crystal furnace 100 includes a flow guide tube 10 and a crucible 30. The crucible 30 contains silicon raw material, which melts into liquid silicon after the melting step. The flow guide tube 10 is positioned directly above the crucible 30 to guide the protective airflow, form a stable airflow field, regulate the temperature field, and assist in forming a temperature gradient during the preparation of the single crystal silicon rod. The liquid outlet distance H1 is the gap between the lower edge of the flow guide tube 10 and the surface of the liquid silicon 40. The liquid silicon 40 is the liquid formed after the silicon raw material is melted. On one hand, the value of the liquid outlet distance H1 affects the volatilization of doping elements and antimony. A larger liquid outlet distance results in a smaller antimony volatilization rate η, and a smaller liquid outlet distance results in a larger antimony volatilization rate η. The antimony volatilization rate η affects the doping concentration of the single crystal silicon rod during growth, thus affecting the resistivity and axial uniformity of the resistivity in the single crystal silicon rod. Therefore, by controlling the volatilization rate η and the liquid outlet distance H1 to satisfy the above relationship, it can be ensured that the volatilization rate η of antimony is always in a relatively stable state during the growth of single crystal silicon rod, thereby keeping the resistivity in the single crystal silicon rod in a stable state, and also avoiding the cost of adding antimony raw materials due to excessive volatilization of antimony.

[0160] Understandably, the volatility of Group III-V elements also affects the doping of hydrogen in the crystal. When the volatility of Group III-V elements is high, the surface tension of the silicon melt decreases, making it easier for hydrogen to form bubbles on the surface of the silicon melt and escape. This reduces the solubility of hydrogen in the silicon melt, resulting in a decrease in the amount of hydrogen doped into the crystal. Therefore, by controlling the value of the liquid outlet distance H1 to control the volatility η of Group III-V elements to an ideal range, it is also possible to further control the ideal doping concentration of hydrogen in the single-crystal silicon rod.

[0161] Understandably, the height of crucible 30 within the single-crystal furnace 100 can be adjusted in real time. During the growth of the single-crystal silicon rod, the liquid level of silicon melt 40 in crucible 30 decreases as the length of the single-crystal silicon rod increases. By real-time detection of the liquid outlet distance H1 within the single-crystal furnace 100 and adjustment of the height of crucible 30, it is ensured that the liquid outlet distance H1 remains essentially constant after the silicon raw material melts to form silicon melt 40. Maintaining an essentially constant liquid outlet distance H1 means that, during the process of maintaining the liquid outlet distance H1 by adjusting the height of crucible 30, the error between the actual liquid outlet distance H1 and the preset liquid outlet distance does not exceed ±5% (approximately ±1 to 2 mm). The height of crucible 30 can be adjusted using a screw jack or hydraulic lifting device, or assisted by an automated control system, or by other height adjustment devices, which will not be elaborated further.

[0162] In some embodiments, the distance H1 between the liquid outlets satisfies: 20mm ≤ H1 ≤ 40mm.

[0163] Understandably, the liquid gate distance H1 (unit: mm) can be any value from 20, 25, 30, 35, 40, or any range between two values. An excessively small liquid gate distance H1 will increase the breakage rate of the single-crystal silicon rod, affecting the crystal formation quality and causing abnormalities such as silicon sputtering and silicon adhesion. Conversely, an excessively large liquid gate distance H1 will make crystal formation too difficult.

[0164] The distance H1 between the liquid outlet and the infrared measuring device is detected by a CCD (Charge-Coupled Device), which can be achieved in the following way:

[0165] 1) Install the CCD infrared measurement device in a position where the liquid surface of silicon liquid 40 inside the single crystal furnace 100 can be clearly observed, such as near the observation window on the side or top of the furnace body. Ensure that the device is installed firmly and can withstand the high temperature and possible vibration of the working environment of the single crystal furnace 100, while ensuring that the optical path is not blocked by other structures or components inside the furnace.

[0166] 2) Use optical components such as infrared lenses and mirrors to construct an optical path so that the infrared radiation emitted from the surface of the silicon liquid 40 can be focused onto the CCD detector.

[0167] 3) After the material preparation is completed, the CCD detector is calibrated for temperature and space, and the signal intensity curves corresponding to the temperature and position of the silicon liquid 40 are recorded.

[0168] 4) In the steps of re-injection, crystal pulling, shoulder placement, shoulder rotation and equal diameter, the acquired infrared images are processed to calculate the height of the liquid surface through the temperature characteristics of the silicon liquid 40, and then the liquid outlet distance H1 is calculated.

[0169] By maintaining a relatively constant liquid outlet distance H1, a stable temperature field and airflow field can be formed within the single crystal furnace 100. On the one hand, this maintains a suitable temperature gradient at the solid-liquid interface, ensuring uniform temperature distribution of the silicon liquid 40 and avoiding abnormal growth and defects in the silicon crystal. On the other hand, it controls the convection of the silicon liquid 40, ensuring uniform distribution of doped elements and further improving the uniformity of doping concentration. It also enables the single crystal silicon rod to grow uniformly, reducing crystal defects and improving the overall quality of the single crystal silicon rod.

[0170] In some embodiments, the volatile rate η satisfies: 5% ≤ η ≤ 25%.

[0171] It is understandable that the volatility η can be any value or a range between any two of the following: 5%, 10%, 15%, 20%, and 25%. When the volatility η meets the above range, the doping concentration of group III-V elements and hydrogen elements during crystal rod growth can be effectively controlled, thereby ensuring that the single crystal silicon rod has uniform resistivity in the axial direction and uniform hydrogen element concentration in the radial direction.

[0172] In some embodiments, a flow guide cylinder 10 is provided inside the single crystal furnace 100. The flow guide cylinder 10 includes a first section 11 and a second section 12 connected to each other, satisfying the following:

[0173] tanα = H2 / W1, and 0 ≤ tanα ≤ 0.58;

[0174] Where α is the angle formed by the second segment 12 and the first direction, in °; H2 is the height of the projection of the second segment 12 in the second direction, in mm; W1 is the length of the projection of the second segment 12 in the first direction, in mm; where the first direction and the second direction intersect.

[0175] Wherein, the included angle α is the angle formed by the second segment 12 and the first direction X, in degrees; H2 is the height of the projection of the second segment 12 in the second direction Y, in mm; W1 is the length of the projection of the second segment 12 in the first direction X, in mm; as Figure 1 As shown, the first direction X is horizontal, and the second direction Y is vertical, intersecting the second direction Y. In some embodiments, the first direction X and the second direction Y are perpendicular to each other.

[0176] In some embodiments, the included angle α can be the included angle formed by the line connecting the beginning and end of the second segment 12 and the first direction X.

[0177] Understandably, the first section 11 of the flow guide tube 10 forms a closed sidewall, typically a cylindrical structure, upright and surrounding the crucible 30. It provides a vertical flow channel for hydrogen and protective gases, allowing the gases to flow in a specific direction, thus ensuring stable convection near the single-crystal silicon rod and crucible 30, and ensuring a consistent crystal growth environment. The second section 12 of the flow guide tube 10 connects to the first section 11 and forms the bottom. The second section 12 extends inward from its connection with the first section 11 into the flow guide tube 10, while tilting towards the side closer to the molten silicon 40, so that the direction of extension of the second section 12 forms an angle α with the first direction X. When tanα = 0, the second section 12 is parallel to the first direction X.

[0178] In some embodiments, the value of tanα is preferably 0.0001≤tanα≤0.58, that is, the second segment 12 forms an acute angle α with the direction of extension and the horizontal direction.

[0179] It is understandable that the value of tanα can be any value or a range between any two of 0.0001, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.58. During the gas flow within the single-crystal furnace 100, the included angle α also affects the volatilization of dopant elements. The larger the included angle α, the lower the real-time volatilization rate of Group III-V elements, while also allowing more oxygen to enter the single-crystal silicon rod. Conversely, the smaller the included angle α, the higher the real-time volatilization rate of Group III-V elements. Therefore, controlling the value of tanα to meet the above-mentioned range ensures that both antimony and oxygen in the single-crystal silicon rod have reasonable contents.

[0180] In some embodiments, the guide tube 10 has a maximum diameter D max ,satisfy:

[0181] D max ≥2W1+W2;

[0182] It is understandable that when the first section 11 of the guide tube 10 is enclosed to form a cylindrical structure, the diameter of the guide tube 10 can gradually decrease along the vertical direction toward the crucible 30, or it can remain unchanged, controlling the maximum diameter D. max By satisfying the above relationships, the flow direction and speed of the protective gas in the single crystal furnace 100 can be further adjusted, thereby improving the stability of the single crystal silicon rod crystal structure during the crystal pulling process.

[0183] In some embodiments, the receiving cavity 13 has a through hole 14 at one end near the silicon liquid 40, and W2 is the maximum size of the through hole 14 in mm. It is understood that W2 is greater than or equal to the target diameter of the single crystal silicon rod.

[0184] In some embodiments, the maximum diameter D max Satisfies: 700mm≤D max ≤1200mm.

[0185] In some embodiments, the length W1 satisfies: 155mm ≤ W1 ≤ 455mm.

[0186] In some embodiments, the maximum dimension W2 satisfies: 290mm≤W2≤390mm.

[0187] In some embodiments, the height H2 satisfies: 0 ≤ H2 ≤ 300 mm.

[0188] Understandably, the maximum diameter D max The values ​​(in mm) of _____ can be any value or any two values ​​between 700, 800, 900, 1000, 1100, and 1200; the values ​​(in mm) of length W1 can be any value or any two values ​​between 155, 200, 250, 300, 350, 400, and 455; the values ​​(in mm) of maximum dimension W2 can be any value or any two values ​​between 290, 310, 330, 350, 370, and 390; the values ​​(in mm) of height H2 can be any value or any two values ​​between 0, 50, 100, 150, 200, 250, and 300. When W1, W2, H2, and D _____, the maximum dimension W2 can be any value or any two values ​​between 290, 310, 330, 350, 370, and 390. max When the above value range is met, the volume Vs of the gas flow region can be within the ideal range, thereby further optimizing the guiding effect of the guide tube 10 in the growth process of single crystal silicon rod, so that the resistivity, oxygen content and hydrogen content of the prepared single crystal silicon rod have ideal uniformity.

[0189] In some embodiments, such as Figure 1 and Figure 3 As shown, the single crystal furnace 100 includes a top cover 20, which is provided with a first vent 21 and a second vent 22. The first vent 21 is arranged around the second vent 22. The first vent 21 is used to introduce hydrogen into the single crystal furnace 100, and the second vent 22 is used to introduce protective gas into the single crystal furnace 100.

[0190] The first vent 21 and the center of the top cover 20 have a first distance D1, and the second vent 22 has a diameter D2, satisfying the following:

[0191] 2D1>D2.

[0192] like Figures 1-3As shown, the second vent 22 is a channel penetrating the top cover 20, and there are several first vents 21, which are arranged around the outer periphery of the second vent 22; the number of first vents 21 is preferably 8 to 10. During the crystal pulling process, hydrogen gas enters the guide tube 10 through the first vent 21 and comes into contact with the silicon liquid 40 in the crucible 30 to achieve doping. The protective gas enters the guide tube 10 through the second vent 22 and flows in the area inside and outside the guide tube 10 to protect the single crystal silicon rod. It can be understood that the protective gas can be directly introduced into the guide tube 10 through the second vent 22, or it can be introduced through a device such as a furnace tube, and then flow through the second vent 22 into the guide tube 10. When the first spacing D1 and the diameter D2 of the second vent satisfy 2D1>D2, the hydrogen gas can have a large flow space in the guide tube 10 and mix thoroughly and evenly with the protective gas, thereby improving the uniformity of the doping process.

[0193] In some embodiments, the first spacing D1 satisfies: 350mm≤D1≤500mm.

[0194] In some embodiments, the diameter D2 of the second vent 22 satisfies: 500mm≤D2≤800mm.

[0195] It is understood that the value of the first spacing D1 (unit: mm) can be any value or a range between any two of 350, 380, 410, 440, 470, and 500. The value of the diameter D2 of the second vent 22 (unit: mm) can be any value or a range between any two of 500, 550, 600, 650, 700, 750, and 800.

[0196] Based on the above embodiments, such as Figure 4 As shown in the shaded area, the first segment 11 and the second segment 12 enclose a receiving cavity 13, within which a first gas flow region 50 is provided. A second gas flow region 60 is provided between the outer wall of the guide tube 10 and the inner wall of the single crystal furnace 100, and between the growing single crystal silicon rod and the inner wall of the single crystal furnace 100. It is understood that the second gas flow region 60 is located within the single crystal furnace 100, and the gas flow region is above the surface of the silicon melt 40. Furthermore, the second gas flow region 60 surrounds the guide tube 10 (and also surrounds the growing single crystal silicon rod). It is understood that the second gas flow region 60 includes a first region 61 and a second region 62, wherein the first region 61 is the region for gas flow between the guide tube 10 and the inner wall of the single crystal furnace 100, and the second region 62 is the region for gas flow located above the surface of the silicon melt 40 and after deducting the volume of the single crystal silicon itself.

[0197] In some embodiments, the volume Vs of the second gas flow region 60 satisfies: Vs = V1 + V2. Wherein, V1 is the first volume of the first region 61, and V2 is the second volume of the second region 62.

[0198] It is understandable that the value of the first volume V1 of the first region 61 is affected by the maximum diameter D of the included angle. max Influenced by the third spacing H3, the value of the second volume V2 of the second region 62 is affected by the orifice distance H1 and the maximum diameter D. max The influence of the first volume V1 and the second volume V2 can be adjusted to change the flow direction and speed of the protective gas in the single crystal furnace 100, so that the gas is split after reaching the crystal growth interface. Therefore, the volume Vs of the second gas flow region 60 can be controlled to have a reasonable size, which can adjust the blowing force of the protective gas on the growth interface of the single crystal silicon rod and improve the stability of the crystal structure of the single crystal silicon rod during the crystal pulling process.

[0199] In some embodiments, the step of adjusting the doping concentration during the solidification process of a single-crystal silicon rod further includes at least one of the following conditions:

[0200] (a) Add an antimony-containing raw material and a phosphorus-containing raw material to a silicon raw material, wherein the mass ratio of the silicon raw material to the antimony-containing raw material and the phosphorus-containing raw material is 1000:(0.05~0.5):(0.005~0.05);

[0201] (b) The temperature range of the temperature stabilization stage is 1450-1500℃, and the time is 1-2h, preferably 1-1.5h;

[0202] (c) Antimony is doped into silicon raw materials using a doping device;

[0203] (d) Antimony is added to silicon raw materials through gas-phase doping.

[0204] In some embodiments, this embodiment also provides a silicon wafer, which is prepared from a single-crystal silicon rod. The silicon wafer contains group III-V elements and hydrogen; the concentration of the group III-V elements is 1E+14cm⁻¹. -3 Up to 8E+15cm -3 The concentration of hydrogen is 2E+13cm. -3 Up to 1E+17cm -3 .

[0205] In some embodiments, the concentration of group III-V elements in the silicon wafer is 2E+14cm⁻¹. -3 Up to 7E+15cm -3 The concentration of hydrogen is 1E+15cm. -3 Up to 7E+16cm -3 .

[0206] In some embodiments, the concentration of group III-V elements is 1E+15cm. -3 Up to 7E+15cm -3 The concentration of hydrogen is 3E+15cm. -3 Up to 6E+16cm -3 .

[0207] In some embodiments, the thickness of the silicon wafer is 70–150 μm.

[0208] In some embodiments, the silicon wafer is circular, and the diameter of the silicon wafer is 223 to 330 mm.

[0209] In some embodiments, this application also provides a method for preparing a single-crystal silicon rod, comprising:

[0210] Silicon-containing raw materials are prepared and placed in a single crystal furnace 100;

[0211] Then, the following steps are performed sequentially: material preparation, re-addition, welding, temperature stabilization, crystal pulling, shoulder expansion, shoulder rotation, and equal diameter measurement to obtain a single crystal silicon rod.

[0212] Hydrogen gas is introduced in at least one of the following steps: material preparation, re-addition, welding, temperature stabilization, crystal pulling, shoulder expansion, shoulder rotation, and equalization; and

[0213] In at least one of the steps of material preparation, re-addition, welding, temperature stabilization, crystal introduction, shoulder expansion, shoulder rotation, and equal diameter, a metallic element or alloy containing at least one of the elements in group III and V is added.

[0214] In some embodiments, the silicon-containing raw material includes virgin polycrystalline silicon or a combination of recycled materials. The raw material can be polycrystalline or granular, or it can be fed in a ratio of 20% to 80% recycled materials.

[0215] In some embodiments, the melting process is specifically carried out using a heater to melt solid silicon into liquid silicon. Before melting, the single crystal furnace 100 is evacuated and leak-checked to ensure the airtightness of the furnace during the crystal pulling process, allowing the single crystal pulling process to proceed smoothly. The melting stage includes the initial melting stage, the middle melting stage, and the later melting stage. When the heater heats the crucible 30, the edge of the crucible 30 is closer to the thermal field and has a higher temperature, while the center of the crucible 30 has a lower temperature. The edge of the crucible 30 melts first, followed by the center and top. Therefore, by controlling the melting power, the rotation speed of the crucible 30, the inert gas flow rate, the hydrogen flow rate, and the pressure inside the single crystal furnace 100, the edge of the crucible 30 is melted first, and the center is melted last, so as to remove impurities and unmelted materials from the crucible 30. The initial crystallization stage involves: a crystallization power of 30-150 kW, a quartz crucible rotation speed of 1-5 r / min, an inert gas flow rate of 40-120 slpm, a hydrogen flow rate of 40-120 slpm, a pressure of 5-30 torr inside the single crystal furnace, and a crystallization time of 1-5 hours. The intermediate crystallization stage involves: a crystallization power of 50-150 kW, a quartz crucible rotation speed of 1-5 r / min, and an inert gas flow rate of 4... The initial reaction time is 0-120 slpm, with a hydrogen flow rate of 40-120 slpm, a pressure of 5-30 torr inside the single crystal furnace 100, and a reaction time of 5-15 hours. In the later stages of reaction: the rotation speed of the quartz crucible 30 is 1-12 r / min, the pressure inside the single crystal furnace 100 is 5-30 torr, the inert gas flow rate is 40-120 slpm, the hydrogen flow rate is 40-120 slpm, and the heater power is 50-150 kW. Inert protective gas is introduced throughout the reaction process; the flow of inert gas helps to remove some impurities and reaction product gases.

[0216] In some embodiments, refeeding refers to using a refeeder to replenish the material to meet the load-bearing requirements of the quartz crucible 30, such as simultaneous doping of conventional alloys. After refeeding, a metal or alloy containing group III-V elements can be introduced into the silicon material. Specifically, after the refeeding is completed and before the seed crystal is fused, the metal or alloy containing group III-V elements is placed in the doping spoon, and after the material is melted, it is placed into the molten silicon 40 before the seed crystal is fused.

[0217] In some embodiments, fusion welding refers to the process of slowly lowering a seed crystal into the molten silicon surface before crystal growth begins, bringing the seed crystal temperature close to the molten silicon temperature, and then allowing the seed crystal to come into contact with the molten silicon. This process is commonly referred to as "seed crystal lowering." After the seed crystal is lowered, it fuses with the molten silicon. Once the surface temperature reaches the requirements for single crystal growth, the surface temperature and the seed crystal lifting speed can be controlled to achieve single crystal growth. The power of the main heater is adjusted to bring the molten silicon temperature in the furnace to 1460 degrees Celsius, and the seed crystal is manually lowered into the molten silicon to melt it, reaching a molten state.

[0218] In some embodiments, during the temperature stabilization stage, the rotation speed of the quartz crucible 30 is 4-12 r / min, the pressure inside the single crystal furnace 100 is 5-30 torr, the flow rate of the inert gas is 40-120 slpm, the flow rate of the hydrogen gas is 40-120 slpm, and the heater power is 30-150 kW. The silicon solution is stabilized at a temperature of 1430-1470°C to facilitate the subsequent crystal pulling process.

[0219] In some embodiments, crystal pulling is a process of effectively eliminating dislocations by adjusting the pulling speed within a suitable range for crystal formation. During crystal pulling, metallic elements or alloys containing group III-V elements can be added. In the crystal pulling stage, the rotation speed of the quartz crucible 30 is 4-12 r / min, the pressure inside the single crystal furnace 100 is 5-30 torr, the flow rate of inert gas is 40-120 slpm, the flow rate of hydrogen is 40-120 slpm, the heater power is 30-150 kW, and the seed crystal rotation speed is 0.5-20 r / min, selected according to actual needs. After preheating the seed crystal, welding and crystal pulling are performed. The average pulling speed during the crystal pulling process is 1-10 mm / min.

[0220] In some embodiments, shoulder formation is the stage of enlarging the diameter of the fine crystals to the required diameter specification; shoulder rotation is the stage of controlling the single crystal production direction from horizontal to vertical, stabilizing the diameter value. In both the shoulder formation and shoulder rotation stages, the shoulder pulling speed is 0.5-10 mm / min, and the seed crystal rotation speed is 0.5-20 r / min. That is, in the shoulder formation stage, the shoulder pulling speed is 0.5-10 mm / min, and the seed crystal rotation speed is 0.5-20 r / min; in the shoulder rotation stage, the shoulder pulling speed is 0.5-10 mm / min, and the seed crystal rotation speed is 0.5-20 r / min, selected according to actual needs.

[0221] In some embodiments, the constant diameter stage is a fully automated control stage for single crystal growth. Different parameters are set within different length ranges of constant diameter based on the volatilization effect of group III-V elements. After the bract is broken, dopant is replenished according to the refeeding process. During the constant diameter growth stage, the rotation speed of the quartz crucible 30 is 4-12 r / min, the pressure inside the single crystal furnace 100 is 5-30 torr, the flow rate of inert gas is 40-120 slpm, the flow rate of hydrogen is 40-120 slpm, the heater power is 30-150 kW, and the seed crystal rotation speed is 0.5-20 r / min.

[0222] In some embodiments, a protective gas is introduced in any one of the steps of material preparation, re-injection, welding, temperature stabilization, crystal pulling, shoulder expansion, shoulder rotation, and equalization; wherein the volume ratio of hydrogen to protective gas is (3-80):100. For example, it can be any one of 3:100, 4:100, 5:100, 8:100, 10:100, 15:100, 20:100, 25:100, 30:100, 35:100, 40:100, 45:100, 50:100, 55:100, 60:100, 65:100, 70:100, 75:100, and 80:100.

[0223] In some embodiments, the hydrogen flow rate is 40–120 slpm. In some other embodiments, the hydrogen flow rate ranges from 60–120 slpm. In some other embodiments, the hydrogen flow rate ranges from 80–120 slpm. In some other embodiments, the hydrogen flow rate ranges from 100–120 slpm.

[0224] In some embodiments, the flow rate of the protective gas is 40–120 slpm. In some other embodiments, the flow rate ranges from 60–120 slpm. In some other embodiments, the flow rate ranges from 80–120 slpm. In some other embodiments, the flow rate ranges from 100–120 slpm. The protective gas is selected from inert gases such as argon and helium.

[0225] In some embodiments, the mass ratio of silicon-containing raw material to the elemental metal or alloy containing group III-V elements is 100:(0.002-0.15). For example, it can be any ratio among 100:0.002, 100:0.005, 100:0.001, 100:0.005, 100:0.008, 100:0.01, 100:0.05, 100:0.1, 100:0.12, and 100:0.15.

[0226] In some embodiments, the furnace pressure of the single crystal furnace 100 is 5 to 30 torr. More preferably, the furnace pressure of the single crystal furnace 100 is 5 to 20 torr. More preferably, the furnace pressure of the single crystal furnace 100 is 5 to 15 torr.

[0227] In some embodiments, the temperature of the single crystal furnace 100 is 1400–1700°C.

[0228] In some embodiments, this embodiment also provides a battery comprising the silicon wafer described above; or, comprising a silicon wafer prepared from a single-crystal silicon rod.

[0229] Example 1

[0230] Polycrystalline silicon blocks or recycled materials are loaded into the quartz crucible 30. For example, solid silicon raw materials are first piled into the quartz crucible 30, and then the quartz crucible 30 filled with silicon material is placed into the single crystal furnace 100.

[0231] The single crystal furnace 100 is evacuated, and the solid silicon in the quartz crucible 30 is gradually melted into a molten state by using a bottom heater and a main heater with a power of 90KW.

[0232] Because the solid silicon material in the quartz crucible 30 is stacked and melted by heating, the actual volume occupied in the quartz crucible 30 is reduced. The melted silicon material does not reach the maximum loading capacity of the quartz crucible 30. Therefore, it is necessary to fill the quartz crucible 30 with silicon material a second time through a refiller. During the filling process, the heater simultaneously melts the silicon material in the quartz crucible 30.

[0233] Phosphorus (P) dopant is loaded into the re-doping device. After the re-doping is completed, antimony (Sb) dopant is loaded into the doping spoon pre-installed in the single crystal furnace 100. After all the silicon material in the quartz crucible 30 has melted, the temperature control process begins. Before the seed crystal is lowered and fused, the Sb dopant in the doping spoon is poured into the molten silicon 40, and the seed crystal is inserted into the liquid surface. By controlling power parameters, the critical crystallization temperature of the liquid surface is reached. The doping amount is calculated based on the target resistivity. Taking a full crucible of 1000 kg as an example, for a single primary polycrystalline addition, a total of 60 g of phosphorus (P) dopant and antimony (Sb) dopant is required.

[0234] After the seed crystal and the liquid surface reach the crystallization temperature point, the seed crystal is pulled upwards. By adjusting parameters such as power and pulling speed, the actual single crystal diameter is placed within the range of 275-285mm for round rod diameter. After the shoulder is formed, the silicon rod equalization process is entered through the shoulder rotation process.

[0235] During the equal diameter process, the furnace pressure is adjusted to 10 torr, the gas flow rate to 100 slpm, the crystal rotation to 9-6 rpm, the crucible rotation to 6-9 rpm, and the power (50KW) is adjusted to reduce antimony volatilization. Once the equal diameter length is 4800mm, the silicon rod pulling is completed by finishing the process.

[0236] In addition to the other processes of the equal diameter process, in order to reduce the volatilization of antimony, the main method is to use a large furnace pressure to suppress the volatilization of antimony, with the furnace pressure between 15-30 torr.

[0237] Each of the above stages requires the introduction of hydrogen and protective argon gas, with a hydrogen / argon volume ratio of 50%; the hydrogen flow rate is 100 slpm and the argon flow rate is 120 slpm.

[0238] Examples 2-8

[0239] The specific preparation process is the same as in Example 1, except that the concentrations of the doped Group III-V elements and hydrogen are different.

[0240] Comparative Examples 1-3

[0241] The specific preparation process is the same as in Example 1, except that hydrogen gas is not introduced and only a single group III-V element is used for doping.

[0242] In this study, the single-crystal silicon rods obtained in Examples 1-8 and Comparative Examples 1-3 were divided into four segments (N=4), each segment having the same size of 10 mm. The second and fourth segments were tested, and the specific characterization parameters are shown in Tables 1, 2, and 3. In Tables 1 and 2, C1 represents the concentration of Group III-V elements at the first end (head) of the second segment, C2 represents the concentration of Group III-V elements at the second end (tail) of the second segment, C3 represents the concentration of Group III-V elements at the first end (head) of the fourth segment, and C4 represents the concentration of Group III-V elements at the second end (tail) of the fourth segment.

[0243] Performance testing

[0244] Resistivity testing: The resistivity of the crystal rod was tested using a KDY~1A resistivity tester.

[0245] The oxygen content test method is as follows: oxygen content is measured at the tip of the crystal rod. The test method is in accordance with GB / T1557~2018. The oxygen content in the crystal rod is tested using a Nicolet 6700 Fourier transform infrared spectrometer.

[0246] Minority carrier lifetime testing: The minority carrier lifetime of the crystal rod was tested using the Sinton BLS-1 minority carrier lifetime tester.

[0247] The resistivity head-to-tail ratio refers to the resistivity at the head (C1 or C3) of each segment divided by the resistivity at the tail (C2 or C4) of each segment.

[0248] Table 1

[0249]

[0250]

[0251]

[0252] Table 2

[0253]

[0254]

[0255]

[0256] Table 3

[0257]

[0258]

[0259] As shown in Tables 1, 2, and 3, doping a specific concentration of hydrogen into Czochralski silicon single crystals can interact with certain concentrations of group III-V elements such as antimony and phosphorus, improving the effective segregation coefficient of group III-V element dopants in crystalline silicon, thereby enhancing the resistivity uniformity of single crystal silicon. Referring to Table 3, the resistivity head-to-tail ratio of Comparative Examples 1-3 is greater than that of Examples 1-8, indicating that the resistivity uniformity of the single crystal silicon rods prepared in this application is higher than that of the comparative examples. At the same time, in Table 3, the comparative examples have higher oxygen content and shorter minority carrier lifetime. Therefore, in this application, by simultaneously doping with group III-V elements and hydrogen, the oxygen content and lifetime of single crystal silicon can be further improved, achieving precise resistivity control and effectively improving the performance and production efficiency of Czochralski silicon single crystals and cells.

[0260] The single-crystal silicon rods and their preparation methods, as well as silicon wafers, provided in the embodiments of this application have been described in detail above. Specific examples have been used in this application to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A single-crystal silicon rod, characterized in that, The single-crystal silicon rod includes a head and a tail opposite each other along its length. From the head to the tail, the single-crystal silicon rod is divided into N silicon rod units, each silicon rod unit having a first end and a second end opposite each other along its length. The single-crystal silicon rod contains a group III-V element and hydrogen. The single-crystal silicon rod satisfies the following: K1=1-((C n-1 -C 氢 ) / (C n -C 氢 And 1E-3≤|K1|≤1E-2; Among them, C 氢 This indicates the hydrogen concentration per unit volume of the single-crystal silicon rod; C n C represents the concentration of Group III-V elements per unit volume at the second end of the nth silicon rod unit; n-1 This represents the concentration of Group III-V elements per unit volume at the first end of the nth silicon rod unit; n is an integer greater than or equal to 1.

2. A single-crystal silicon rod according to claim 1, characterized in that, The dimensions of any one of the N silicon rod units in the length direction are equal to those of each other; and / or, The dimension of any one of the N silicon rod units in the length direction is A mm, satisfying: 1 ≤ A ≤ 50; and / or, N is an integer greater than or equal to 1 and less than or equal to 6000.

3. A single-crystal silicon rod according to claim 1, characterized in that, The hydrogen concentration per unit volume C in the single crystal silicon rod 氢 Satisfy: 2E+13cm -3 ≤C 氢 ≤1E+17cm -3 ;or, The hydrogen concentration per unit volume C in the single crystal silicon rod 氢 Satisfy: 1E+15cm -3 ≤C 氢 ≤7E+16cm -3 ;or, The hydrogen concentration per unit volume C in the single crystal silicon rod 氢 Satisfying: 3E+15cm -3 ≤C 氢 ≤6E+16cm -3 .

4. A single-crystal silicon rod according to claim 1, characterized in that, The concentration of Group III-V elements per unit volume C at the second end of the silicon rod unit in the nth segment. n Satisfy: 1E+14cm -3 ≤C n ≤8E+15cm -3 ;or, The concentration of Group III-V elements per unit volume C at the second end of the silicon rod unit in the nth segment. n Satisfies: 2E+14cm -3 ≤C n ≤7E+15cm -3 ; or, The concentration of Group III-V elements per unit volume C at the second end of the silicon rod unit in the nth segment. n Satisfy: 1E+15cm -3 ≤C n ≤7E+15cm -3 .

5. A single-crystal silicon rod according to claim 4, characterized in that, The concentration of Group III-V elements per unit volume of the nth silicon rod unit at the first end is C. n-1 Satisfy: 1E+14cm -3 ≤C n ≤8E+15cm -3 ; or, The concentration of Group III-V elements per unit volume of the nth silicon rod unit at the first end is C. n-1 Satisfies: 2E+14cm -3 ≤C n ≤7E+15cm -3 ; or, The concentration of Group III-V elements per unit volume of the nth silicon rod unit at the first end is C. n-1 Satisfy: 1E+15cm -3 ≤C n ≤7E+15cm -3 .

6. A single-crystal silicon rod according to claim 1, characterized in that, The actual effective segregation coefficient of the group III-V elements in the single-crystal silicon rod is K. 有效 ,satisfy: TO 有效 =K0 / (K0+(1-K0)×EXP((-1)×(V / 600)×δ / (10×D)))×(1-K1); Wherein, K0 is the original effective segregation coefficient of group III-V elements in single-crystal silicon rods; V represents the crystal pulling speed in mm / min; δ represents the boundary layer thickness in mm; D is the diffusion coefficient in cm; and K1 represents the correction coefficient after the combined effect of hydrogen and group III-V elements.

7. A single-crystal silicon rod according to claim 6, characterized in that, The boundary layer thickness δ ranges from 0.005 to 0.05 mm; and / or, The crystal pulling speed V is in the range of 1.1–2.2 mm / min; and / or, The diffusion coefficient D ranges from 0.0001 to 0.001 cm.

8. A single-crystal silicon rod according to claim 6, characterized in that, The actual effective segregation coefficient K of the group III-V elements in the single-crystal silicon rod 有效 Further satisfying: 0.005 ≤ K 有效 ≤0.38; or, The actual effective segregation coefficient K of the group III-V elements in the single-crystal silicon rod 有效 Further satisfy: 0.005≤K 有效 ≤0.03; or, The actual effective segregation coefficient K of the group III-V elements in the single-crystal silicon rod 有效 Further satisfy: 0.005≤K 有效 ≤0.028; or, The actual effective segregation coefficient K of the group III-V elements in the single-crystal silicon rod 有效 Further satisfy: 0.005≤K 有效 ≤0.018。 9. A single-crystal silicon rod according to claim 1, characterized in that, The resistivity of the single-crystal silicon rod is ρΩ·cm, satisfying: 0.1≤ρ≤7; or The resistivity of the single-crystal silicon rod is ρΩ·cm, satisfying: 0.4≤ρ≤1.5; or The resistivity of the single-crystal silicon rod is ρΩ·cm, satisfying: 0.6≤ρ≤1.5; or The resistivity of the single-crystal silicon rod is ρΩ·cm, which satisfies: 0.8≤ρ≤1.

4.

10. A single-crystal silicon rod according to claim 1, characterized in that, The group III-V elements are selected from at least one of antimony, phosphorus, gallium, boron, and arsenic.

11. A method for preparing a single-crystal silicon rod, characterized in that, include: A silicon raw material is provided, and a single crystal silicon rod is obtained through the steps of material preparation, repeated feeding, temperature stabilization, crystal pulling, shoulder formation, equal diameter formation, and finishing. In at least one of the steps of material preparation, repeated feeding, temperature stabilization, crystal pulling, shoulder formation, equal diameter formation, and finishing, hydrogen gas is introduced into the silicon raw material. Before the equal diameter formation step, a raw material containing group III-V elements is added to the silicon raw material. Specifically, before the single-crystal silicon rod is fully grown, the doping concentration during the solidification process of the single-crystal silicon rod is adjusted to control the doping ratio of hydrogen and the group III-V elements to meet the following requirements: K1=1-((C n-1 -C 氢 ) / (C n -C 氢 And 1E-3≤|K1|≤1E-2; In the formula, C 氢 This indicates the hydrogen concentration per unit volume of the single-crystal silicon rod; C n C represents the concentration of Group III-V elements per unit volume at the second end of the nth silicon rod unit; n-1 This represents the concentration of Group III-V elements per unit volume at the first end of the nth silicon rod unit; n is an integer greater than or equal to 1.

12. The method for preparing a single-crystal silicon rod according to claim 11, characterized in that, The time required to introduce hydrogen gas into the silicon raw material satisfies the following: t 总 =t1+t2+t3+t4+t5+t6+t7, and 0.5h≤t 总 ≤82h; Among them, t 总 The total time for introducing hydrogen is t1, which is the time for introducing hydrogen during the material preparation stage; t2 is the time for introducing hydrogen during the re-feeding stage; t3 is the time for introducing hydrogen during the temperature stabilization stage; t4 is the time for introducing hydrogen during the crystallization stage; t5 is the time for introducing hydrogen during the shoulder formation stage; t6 is the time for introducing hydrogen during the equal diameter stage; and t7 is the time for introducing hydrogen during the finishing stage.

13. The method for preparing a single-crystal silicon rod according to claim 12, characterized in that, The time for introducing hydrogen gas into the silicon raw material also satisfies: t1: t2: t3: t4: t5: t6: t7=(0~10): (0~8): (0~2): (0~1.5): (0~3): (0～55)：(0～2)。 14. The method for preparing a single-crystal silicon rod according to claim 11, characterized in that, Also includes: After the re-feeding step, a protective gas is introduced into the silicon raw material; Wherein, the hydrogen gas and the protective gas form a mixed gas, and the volume percentage of the hydrogen gas in the mixed gas is 1-90%, preferably 5-90%; or, The flow rate of the hydrogen gas is 0.0001–180 slpm; or, The flow rate of the protective gas is 40–200 slpm.

15. The method for preparing a single-crystal silicon rod according to claim 11, characterized in that, Before the end of the re-addition step and the beginning of the isodiameter step, the volatilization rate η of the group III-V elements is controlled to satisfy: η=(H1 / 100mm)×100%-15%; Wherein, H1 is the liquid outlet distance in the single crystal furnace, in mm; the volatility η satisfies: 5% ≤ η ≤ 25%; the liquid outlet distance H1 satisfies: 20mm ≤ H1 ≤ 40mm.

16. The method for preparing a single-crystal silicon rod according to claim 15, characterized in that, The single crystal furnace is equipped with a flow guide tube, which includes a first section and a second section connected to each other, satisfying the following: tanα = H2 / W1, and 0 ≤ tanα ≤ 0.58; Where α is the angle formed by the second segment and the first direction, in °; H2 is the height of the projection of the second segment in the second direction, in mm; W1 is the length of the projection of the second segment in the first direction, in mm; and the first direction and the second direction intersect.

17. The method for preparing a single-crystal silicon rod according to claim 11, characterized in that, The step of adjusting the doping concentration during the solidification process of the single-crystal silicon rod further includes at least one of the following conditions: (a) Adding an antimony-containing raw material and a phosphorus-containing raw material to the silicon raw material, wherein the mass ratio of the silicon raw material to the antimony-containing raw material and the phosphorus-containing raw material is 1000:(0.05~0.5):(0.005~0.05); (b) The temperature range of the temperature stabilization stage is controlled to be 1450-1500°C, and the time is 1-2 hours, preferably 1-1.5 hours; (c) The antimony element is doped using a doping device to be added to the silicon raw material; (d) The antimony element is added to the silicon raw material by gas-phase doping.

18. A silicon wafer, characterized in that, The silicon wafer is prepared from a single-crystal silicon rod as described in any one of claims 1-10 or from a single-crystal silicon rod prepared by the preparation method described in any one of claims 11-17; the silicon wafer contains group III-V elements and hydrogen; wherein the concentration of the group III-V elements is 1E+14cm⁻¹. -3 Up to 8E+15cm -3 The concentration of hydrogen is 2E+13cm. -3 Up to 1E+17cm -3 ;or The concentration of the group III-V elements is 2E+14cm. -3 Up to 7E+15cm -3 The concentration of hydrogen is 1E+15cm. -3 Up to 7E+16cm -3 ;or, The concentration of the group III-V elements is 1E+15cm. -3 Up to 7E+15cm -3 The concentration of hydrogen is 3E+15cm. -3 Up to 6E+16cm -3 .

19. A solar cell, characterized in that, Includes a silicon substrate, said silicon substrate being prepared from the silicon wafer of claim 19; The resistivity of the silicon substrate is 0.5-3 ΩΩcm, and the thickness is 120-160 μm.

20. A solar cell according to claim 19, characterized in that, The silicon substrate includes a doped region, which is doped with hydrogen and group III-V elements; The hydrogen concentration in the doped region is 2E+13cm⁻¹ -3 ~1E+17cm -3 ; The concentration of Group III-V elements in the doped region is 1E+14cm⁻¹ -3 ~8E+15cm -3 .

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