Examination of a silicon substrate for a solar cell

1. Method for manufacturing a solar cell, wherein a wire-sawn silicon substrate is provided that is selected by carrying out the steps of:

irradiating the silicon substrate with an infrared radiation having a wavelength within the range of 800 nm to 1200 nm;

detecting the infrared radiation transmitted through the silicon substrate;

analyzing the detected infrared radiation to determine a crystal orientation of the silicon substrate; and

determining a percentage of the surface of the silicon substrate having the crystal orientation,

wherein depending on the selection of the silicon substrate, one of the following step is carried out:

forming a surface texture of the silicon substrate by carrying out an alkaline etching process;

forming a surface texture of the silicon substrate by carrying out an acidic etching process; or

sorting out the silicon substrate.

2. Method according to claim 1 , wherein a frequency distribution related to a surface of the silicon substrate is formed from different intensities of the detected infrared radiation.

3. Method according to claim 1 , wherein:

a total frequency distribution of different intensities of the detected infrared radiation related to a surface of the silicon substrate is determined,

a further frequency of intensities of the detected infrared radiation is determined, which is associated to regions of the silicon substrate with the crystal orientation, and

a ratio is formed from the further frequency and the total frequency.

4. Method according to claim 1 , wherein an association is established between the crystal orientation and the intensities of the detected infrared radiation.

5. Method according to claim 4 , wherein the association is established based on a peak value in a frequency distribution of different intensities of the detected infrared radiation.

6. Method according to claim 4 , wherein the association is established based on a calibration measurement.

7. Method according to claim 1 , wherein a spatial distribution of the crystal orientation is determined over the surface of the silicon substrate.

8. Method according to claim 1 , wherein the silicon substrate includes a monocrystalline crystal structure, and wherein the crystal orientation is a 100-crystal orientation.

9. Device for selecting the silicon substrate according to claim 1 , including:

an irradiation device for irradiating a wire-sawn silicon substrate for a solar cell with an infrared radiation;

a detection device for detecting the infrared radiation transmitted through the silicon substrate; and

an evaluation device for analyzing the detected infrared radiation in order to determine the crystal orientation of the silicon substrate.

10. Device according to claim 9 , wherein the evaluation device is configured to form a frequency distribution of different intensities of the detected infrared radiation related to a surface of the silicon substrate, and to determine the percentage of the surface of the silicon substrate with the crystal orientation based on the frequency distribution.