Mechanically grooved, double sided, buried contact silicon solar cells

The groove formation is an important step in the production of buried contact solar cells. This often involves the alignment and scribing of individual wafers in turn, which results in a low production throughput and a possible increase in the cost of production. To increase the production throughput and reduce the cost of scribing, a batch scribing of wafers would be necessary. However, the batch grooving of cells is not easily obtained with the scribing techniques such as laser, photolithography and plasma etching, but can be achieved with the mechanical scriber. The mechanical scriber using rotating blades is restricted to cutting in only one direction while the use of a diamond point scriber in conjunction with a drafting plotter (as used in this work) is capable of scribing 63 (4 inch) wafers in a matrix on the plotter. The adapted plotter was used to form the grooves of the double sided buried contact (DSBC) silicon solar cells. The DSCB structure is based on the single sided buried contact (SSBC) cells [1] with the added advantages of potentially higher conversion efficiency and lower production cost. The use of mechanical scribing rather than laser scribing to form the grooves in the silicon substrate has no detrimental effect on the performance of the device and may have the potential to significantly reduce production costs.