Abstract: A method for determining the thermal donor concentration of a test sample made of a semiconductor material, includes providing a reference sample made of the same semiconductor material and having a known thermal donor concentration; measuring a photoluminescence signal of the reference sample for a photon energy comprised between 0.65 eV and 0.8 eV, the photoluminescence signal of the reference sample exhibiting an intensity peak in a photon energy range of 0.65 eV to 0.8 eV; determining, from the photoluminescence signal, an experimental relationship between the thermal donor concentration and a parameter representative of the intensity peak; measuring a photoluminescence signal of the test sample for at least one photon energy comprised between 0.65 eV and 0.8 eV; determining from the photoluminescence signal a specific value of the parameter; and determining the thermal donor concentration from the specific value of the parameter by using the experimental relationship.

Abstract: Photovoltaic cell comprising, an assembly comprising a substrate, first and second passivation layers covering opposite faces of the substrate and also lateral faces of the substrate, and first and second charge-collecting layers; a first layer of TCO disposed against the first main face of the assembly and such that edges of the first main face of the assembly are not covered by the first layer of TCO; a second layer of TCO covering the whole of the second main face of the assembly; a non-reflective coating partly covering the first and/or second charge-collecting layers on the lateral faces of the substrate and not covered by the second layer of TCO, and also covering the edges of the first main face.

Abstract: A plate configured to support at least one substrate during a deposition of material on the substrate, including at least: a solid holding surface on which a main face of the substrate is intended to be placed during the deposition, the dimensions of which are smaller than those of the main face of the substrate so that edges of the main face of the substrate are not in contact with the solid holding surface; connecting elements forming arms mechanically connecting the solid holding surface to a frame of the plate.

Abstract: Photovoltaic cell comprising: an assembly comprising a substrate, first and second passivation layers covering opposite faces of the substrate and also lateral faces of the substrate, and first and second charge-collecting layers; a first layer of TCO disposed against the first main face of the assembly and such that edges of the first main face of the assembly are not covered by the first layer of TCO; a second layer of TCO covering the whole of the second main face of the assembly; a non-reflective coating partly covering the first and/or second charge-collecting layers on the lateral faces of the substrate and not covered by the second layer of TCO, and also covering the edges of the first main face.

Abstract: An experimental method for validating a thermal history of a semiconductor ingot obtained by simulation of a crystallization process, includes a) measuring the concentration of interstitial oxygen in a portion of the semiconductor ingot; b) calculating a theoretical value of the concentration of thermal donors formed during the crystallization process, from the measurement of the concentration of interstitial oxygen and from the thermal history in the portion of the semiconductor ingot; c) measuring an experimental value of the concentration of thermal donors in the portion of the semiconductor ingot; and d) comparing the theoretical and experimental values of the concentration of thermal donors.

Abstract: A method for determining the thermal donor concentration of a test sample made of a semiconductor material, includes providing a reference sample made of the same semiconductor material and having a known thermal donor concentration; measuring a photoluminescence signal of the reference sample for a photon energy comprised between 0.65 eV and 0.8 eV, the photoluminescence signal of the reference sample exhibiting an intensity peak in a photon energy range of 0.65 eV to 0.8 eV; determining, from the photoluminescence signal, an experimental relationship between the thermal donor concentration and a parameter representative of the intensity peak; measuring a photoluminescence signal of the test sample for at least one photon energy comprised between 0.65 eV and 0.8 eV; determining from the photoluminescence signal a specific value of the parameter; and determining the thermal donor concentration from the specific value of the parameter by using the experimental relationship.

Abstract: A method of analysis of defects of a type from among a plurality of types of defects between two samples based on an image of each sample characteristic of a type of defect from among the plurality of types of defects includes: for each sample, creating a minimap including bins and representative of a type of defect whose resolution is less than the image of the sample, each bin of the minimap being associated with pixels of the image of the sample and having a score dependent on the pixels and representative of the quantity of a type of defects; determining the distance between each minimap representing the same type or types of defects, the distance between two minimaps being defined as the minimum distance between two minimaps by considering the following transformations: a rotation and/or a symmetry so that each distance between two minimaps is associated with a transformation.

Abstract: A Czochralski-type method for sorting wafers obtained by cutting a single-crystal silicon ingot, the method being implemented when the wafers are in an as-cut state or in a shaped-surface state. The method includes a) measuring the majority free charge carrier concentration in an area of each wafer; calculating the thermal donor concentration in the area of each wafer, on the basis of the majority free charge carrier concentration; calculating the charge carrier lifetime limited by the thermal donors in the area of each wafer, on the basis of the thermal donor concentration; determining a bulk lifetime value for the charge carriers in each wafer on the basis of the lifetime limited by the thermal donors; comparing the bulk lifetime value or a normalised bulk lifetime value with a threshold value; and discarding the wafer when the bulk lifetime value or the normalised bulk lifetime value is lower than the threshold value.

Abstract: A method and system for monitoring the quality of photovoltaic cells is described, the method including for each cell: an excitation step, during which the cell to be monitored is subjected to excitation at a predetermined level of excitation; a step of acquiring at least one luminescence image of the cell to be monitored after excitation; and a step of processing the acquired image. The invention is characterized in that, for each cell, there is provided a preliminary step for determining an excitation level adjusted to the cell, the respective adjusted excitation levels of the different cells to be monitored being adapted such that the luminescence intensities of the signals emitted by the different cells are equal at a given reference luminescence intensity.

Abstract: An experimental method for validating a thermal history of a semiconductor ingot obtained by simulation of a crystallization process, includes a) measuring the concentration of interstitial oxygen in a portion of the semiconductor ingot; b) calculating a theoretical value of the concentration of thermal donors formed during the crystallization process, from the measurement of the concentration of interstitial oxygen and from the thermal history in the portion of the semiconductor ingot; c) measuring an experimental value of the concentration of thermal donors in the portion of the semiconductor ingot; and d) comparing the theoretical and experimental values of the concentration of thermal donors.

Abstract: A Czochralski-type method for sorting wafers obtained by cutting a single-crystal silicon ingot, the method being implemented when the wafers are in an as-cut state or in a shaped-surface state. The method includes a) measuring the majority free charge carrier concentration in an area of each wafer; calculating the thermal donor concentration in the area of each wafer, on the basis of the majority free charge carrier concentration; calculating the charge carrier lifetime limited by the thermal donors in the area of each wafer, on the basis of the thermal donor concentration; determining a bulk lifetime value for the charge carriers in each wafer on the basis of the lifetime limited by the thermal donors; comparing the bulk lifetime value or a normalised bulk lifetime value with a threshold value; and discarding the wafer when the bulk lifetime value or the normalised bulk lifetime value is lower than the threshold value.

Abstract: A method and system for monitoring the quality of photovoltaic cells is described, the method including for each cell: an excitation step, during which the cell to be monitored is subjected to excitation at a predetermined level of excitation; a step of acquiring at least one luminescence image of the cell to be monitored after excitation; and a step of processing the acquired image. The invention is characterized in that, for each cell, there is provided a preliminary step for determining an excitation level adjusted to the cell, the respective adjusted excitation levels of the different cells to be monitored being adapted such that the luminescence intensities of the signals emitted by the different cells are equal at a given reference luminescence intensity.

Abstract: A method and system for monitoring the quality of photovoltaic cells is described, the method including for each cell: an excitation step, during which the cell to be monitored is subjected to excitation at a predetermined level of excitation; a step of acquiring at least one luminescence image of the cell to be monitored after excitation; and a step of processing the acquired image. The invention is characterized in that, for each cell, there is provided a preliminary step for determining an excitation level adjusted to the cell, the respective adjusted excitation levels of the different cells to be monitored being adapted such that the luminescence intensities of the signals emitted by the different cells are equal at a given reference luminescence intensity.

Abstract: A method and system for monitoring the quality of photovoltaic cells is described, the method including for each cell: an excitation step, during which the cell to be monitored is subjected to excitation at a predetermined level of excitation; a step of acquiring at least one luminescence image of the cell to be monitored after excitation; and a step of processing the acquired image. The invention is characterized in that, for each cell, there is provided a preliminary step for determining an excitation level adjusted to the cell, the respective adjusted excitation levels of the different cells to be monitored being adapted such that the luminescence intensities of the signals emitted by the different cells are equal at a given reference luminescence intensity.