Abstract: A method is disclosed whereby luminescence images are captured from as-cut or partially processed bandgap materials such as multicrystalline silicon wafers. These images are then processed to provide information about defects such as dislocations within the bandgap material. The resultant information is then utilized to predict various key parameters of a solar cell manufactured from the bandgap material, such as open circuit voltage and short circuit current. The information may also be utilized to apply a classification to the bandgap material. The methods can also be used to adjust or assess the effect of additional processing steps, such as annealing, intended to reduce the density of defects in the bandgap materials.

Abstract: A method (1) is disclosed whereby luminescence images are captured (2) from as-cut or partially processed bandgap materials such as multicrystalline silicon wafers. These images are then processed (3) to provide information about defects such as dislocations within the bandgap material. The resultant information is then utilised (4) to predict various key parameters of a solar cell manufactured from the bandgap material, such as open circuit voltage and short circuit current. The information may also be utilised to apply a classification to the bandgap material. The methods can also be used to adjust or assess the effect of additional processing steps, such as annealing, intended to reduce the density of defects in the bandgap materials.

Abstract: A method is disclosed whereby luminescence images are captured from as-cut or partially processed bandgap materials such as multicrystalline silicon wafers. These images are then processed to provide information is then utilized to predict various key parameters of a solar cell manufactured from the bandgap material, such as open circuit voltage and short circuit current. The information may also be utilized to apply a classification to the bandgap material. The methods can also be used to adjust or assess the effect of additional processing steps, such as annealing, intended to reduce the density of defects in the bandgap materials.

Abstract: Methods and systems are presented for acquiring photoluminescence images (2) of silicon solar cells and wafers (4) as they progress along a manufacturing line (36). In preferred embodiments the images are acquired while maintaining motion of the samples. In certain embodiments photoluminescence is generated with short pulse, high intensity excitation, (8) for instance by a flash lamp (50) while in other embodiments images are acquired in line scanning fashion. The photoluminescence images can be analysed to obtain information on average or spatially resolved values of one or more sample properties such as minority carrier diffusion length, minority carrier lifetime, dislocation defects, impurities and shunts, or information on the incidence or growth of cracks in a sample.

Abstract: Methods are presented for analysing semiconductor materials (8), and silicon photovoltaic cells and cell precursors in particular, using imaging of photoluminescence (12) generated with high intensity illumination (16). The high photoluminescence signal levels (16) obtained with such illumination (30) enable the acquisition of images from moving samples with minimal blurring. Certain material defects of interest to semiconductor device manufacturers, especially cracks, appear sharper under high intensity illumination. In certain embodiments images of photoluminescence generated with high and low intensity illumination are compared to highlight selected material properties or defects.

Abstract: A method (1) is disclosed whereby luminescence images are captured (2) from as-cut or partially processed bandgap materials such as multicrystalline silicon wafers. These images are then processed (3) to provide information about defects such as dislocations within the bandgap material. The resultant information is then utilised (4) to predict various key parameters of a solar cell manufactured from the bandgap material, such as open circuit voltage and short circuit current. The information may also be utilised to apply a classification to the bandgap material. The methods can also be used to adjust or assess the effect of additional processing steps, such as annealing, intended to reduce the density of defects in the bandgap materials.