GB/T 26071-2026Monocrystalline silicon and wafers for solar cells (English PDF)

4.2 Classification

4.2.1 Silicon single crystals and silicon wafers are classified into two types according to their conductivity. p-type and n-type.

4.2.2 Silicon single crystal end faces and silicon wafers can be classified into three types according to their shape. quasi-square, square, and rectangular. The dimensions of quasi-square, square, and rectangular wafers should conform to... The provisions in Table 1 apply. Any other requirements shall be determined through negotiation between the supplier and the buyer.

5.3 Physical and chemical properties

5.3.1 Interstitial oxygen content The interstitial oxygen content in p-type silicon single crystals and wafers should not exceed 1.0 × 10^18 cm^-3 (20 ppma), while the interstitial oxygen content in n-type silicon single crystals and wafers should not exceed 1.0 × 10^18 cm^-3 (20 ppma). The content should not exceed 9.0×10^17cm^-3 (18ppma), or be determined by negotiation between the supplier and the buyer.

5.3.2 Substitution carbon content The substitutional carbon content of p-type silicon single crystals and silicon wafers should not exceed 5.0 × 10^16 cm^-3 (1 ppma), and the substitutional carbon content of n-type silicon single crystals and silicon wafers should not exceed 5.0 × 10^16 cm^-3 (1 ppma). The quantity should not exceed 5.0 × 10^16 cm^-3 (1 ppma), or be determined through negotiation between the supplier and the buyer.

5.4 Crystal Integrity There should be no twins inside a silicon single crystal. The dislocation density of silicon single crystals and silicon wafers should not exceed 500 dislocations/cm2, and there should be no slip dislocations.

5.5 Geometric Parameters The geometric parameters of the silicon wafers shall conform to the specifications in Table

3.Any other requirements shall be determined through negotiation between the supplier and the buyer.

5.6 Verticality The perpendicularity between any two adjacent sides of a silicon single crystal and between any two adjacent sides of a silicon wafer is 90° ± 0.2°.

5.7 External Dimensions

5.7.1 Quasi-square silicon single crystal end face and silicon wafer dimensions The quasi-square silicon single crystal end face and the shape of the silicon wafer are shown in Figure

1.The dimensions should conform to the specifications in Table

4.If there are other requirements, they shall be determined by both the supplier and the buyer. The parties agreed upon this through consultation.

5.7.2 Square silicon single crystal end face and silicon wafer dimensions The square silicon single crystal end face and the shape of the silicon wafer are shown in Figure

2.The dimensions should conform to the specifications in Table

5.Any other requirements shall be determined by both the supplier and the buyer.

5.7.3 Rectangular silicon single crystal end face and silicon wafer dimensions The rectangular silicon single crystal end face and the shape of the silicon wafer are shown in Figure

3.The dimensions should conform to the specifications in Table

6.Any other requirements shall be determined by both the supplier and the buyer. The agreement was reached through negotiation.

5.8 Surface Quality

5.8.1 Silicon Single Crystal The surface and end faces (including the quasi-square chamfered surface) of silicon single crystals should be flat and smooth, free from obvious scratches, color differences, and dirt, and should not have cracks or defects. The total length of the chipped edge on the end face should not exceed 8mm.

5.8.2 Silicon Wafer The surface quality of silicon wafers should meet the requirements of Table 7.

7.1 Inspection and Acceptance

7.1.1 The supplier shall inspect the products to ensure that the product quality meets the requirements of this document and the purchase order, and fill out a product quality guarantee certificate.

7.1.2 The buyer may inspect the received products in accordance with the provisions of this document. If the inspection results do not conform to the provisions of this document or the purchase order, the buyer shall be liable for compensation. In such cases, the supplier should be notified within 3 months of receiving the product, and the matter should be resolved through negotiation between the supplier and the buyer.

7.2 Batching Products are submitted for acceptance in batches. Each batch of silicon single crystals should consist of products of the same grade, same conductivity type (including doping type), and same external dimensions. Product composition. Each batch of silicon wafers should consist of products with the same external dimensions, the same conductivity type (including doping type), and the same resistivity range.

7.3 Inspection Items

7.3.1 Silicon Single Crystal Each batch of silicon single crystals should be tested for conductivity type, resistivity range, radial resistivity variation, carrier recombination lifetime, crystal orientation and crystal orientation deviation, and inter-phase conductivity. The oxygen content, substitutional carbon content, crystal integrity, perpendicularity, dimensions, and surface quality are inspected.

7.3.2 Silicon Wafer Each batch of silicon wafers must be inspected for resistivity range, geometric parameters, dimensions, and surface quality. The conductivity type and carrier recombination lifetime of the silicon wafers must also be considered. Whether the crystal's life, crystal orientation and deviation, interstitial oxygen content, substitutional carbon content, and crystal integrity need to be inspected shall be determined through negotiation between the supplier and the buyer.

7.4 Sampling

7.4.1 Silicon Single Crystal Sampling shall be conducted in accordance with the provisions of Table

8.Any other requirements shall be determined through negotiation between the supplier and the buyer.

7.4.2 Silicon Wafer

7.4.2.1 Except for conductivity type, carrier recombination lifetime, crystal orientation and deviation, interstitial oxygen content, substitutional carbon content, and crystal integrity. Project inspection sampling shall be conducted in accordance with the general inspection level II, normal inspection single sampling plan in GB/T 2828.1-2012, or by both the supplier and the buyer. The sampling plan determined through consultation will be implemented.

7.4.2.2 Sampling shall be conducted in accordance with the provisions of Table

9.Any other requirements shall be determined through negotiation between the supplier and the buyer.

7.5.1 Silicon Single Crystal

7.5.1.1 If any test result for conductivity type, carrier recombination lifetime, external dimensions, or surface quality fails to meet the requirements, the silicon single crystal is deemed unqualified. qualified.

7.5.1.2 Resistivity range, radial resistivity variation, crystal orientation and deviation, interstitial oxygen content, substitutional carbon content, and crystal integrity are determined using... Sampling inspection. If two or more samples out of four are found to be non-compliant, double the number of samples should be taken for repeated testing. If the test results still fail to meet the standards, the batch of silicon single crystals is deemed unqualified; if one or two out of three or fewer samples fail to meet the standards... If the sample fails to meet the standard, double the number of samples should be taken for repeated testing. If the repeated test results are still unqualified, the batch of products is deemed unqualified.

7.5.1.3 The determination of the surface quality inspection results shall be determined through consultation between the supplier and the buyer.

7.5.2 Silicon Wafer The Acceptable Quality Limit (AQL) for silicon wafers is shown in Table 10.

8.2 Packaging, Transportation and Storage

8.2.1 Packaging Product packaging shall comply with the provisions of YS/T 28, or be determined by the supplier and the buyer through negotiation.

8.2.2 Transportation Products should be handled with care during transportation, and should not be thrown. Shockproof and moisture-proof measures should be taken.

8.2.3 Storage The product should be stored in a clean, dry environment.

8.3 Accompanying Documents Each batch of products should be accompanied by documentation stating.

a) Supplier's name;

b) Product name or brand;

c) Product batch number;

d) Product quantity;

e) All test results and the official seal of the testing department;

f) This document number;

g) Date of manufacture.

9.Order details The order form for the products listed in this document should include the following information.

a) Product Name;

b) Product requirements;