PLASMA-GROOVED, BURIED CONTACT SILICON SOLAR-CELLS

Solar cells with less than 1% front-surface metal shading loss have been made with a deep-grooving hollow cathode dry etching process. Compared with standard laser-grooved cells, a 4% relative increase in short-circuit current density has been demonstrated. Open-circuit voltages of over 640 mV (air mass 1.5, 25-degrees-C), a fill factor of almost 79%, and the application of an antireflection coating have resulted in a one-sun efficiency of 19.2%. This is one of the highest efficiencies yet reported for a cleaved 4 cm2 silicon solar cell.