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Lasers (e.g. Nd-YAG) have been used extensively for groove formation both in laboratories and commercial production but the initial capital cost is high. The production throughput is also low and thus adds to the cost of the cell. To reduce cost and increase production throughput a drafting plotter has been adapted to serve as a mechanical scriber for groove formation. The adapted plotter can scribe cells in matrix form to reduce the human labour and increase the production throughput. The characterization of the scribing tips in conjunction with the plotter showed that the best yield for the scriber is obtained when the scribing tip is mounted at 78 [degrees] to the stock. Of the seven characterized scribing tips, the 90 [degrees] conical scriber has been found to give the same groove geometry as the laser. The application of the adapted plotter to cell fabrication did not show any significant deterioration in the electrical output parameters for the mechanically scribed cells when compared with laser scribed cells. This article reports the adaptation of the x-y table drafting plotter to form buried contact grooves.

Significant improvements are reported in the energy conversion efficiency of low resistivity silicon solar cells when measured under concentrated sunlight. These improvements result primarily from increased short-circuit current density due to the use of a microgrooved cell structure with obliquely transversing metallization fingers. Peak efficiencies are 23.6% at 100 suns concentration with values up to 22.7% maintained at 273 suns concentration. [ABSTRACT FROM AUTHOR]