EASY & SIMPLE silicon solar cell concept for concentrated sunlight

Abstract

The overall aim to lower the cost and realize a high efficiency photovoltaic system can be achieved by concentrator systems since, compared to non-concentrating systems, the solar cells are replaced by more cost-effective optical devices. The EASY & SIMPLE (Especially Advanced Structuring with high Yield & Selective emitter IMPLEmentation) silicon solar cell concept is an approach combining straight forward solar cell processing with medium to high light concentration. The EASY & SIMPLE cell concept is based on mechanical V-grooving of the front surface and a subsequent definition of the contact area along the ridges. The front contacts can be defined by mechanical means, using a conventional dicing saw or by a self-aligning SiN deposition, both processes avoid the use of photolithography. The V-grooved surface serves as a means for relaxing the requirements for tracking if adequately installed. Additionally, the V-grooved front surface opens the opportunity to apply the SAFE (Shallow Angle Finger Evaporation) metallisation scheme (5). As an alternative to this technique, an electroless plating process depositing nickel and copper as has been applied in the same way as to the similar LOPE (LOcal Point contact and shallow angle Evaporation) solar cell concept (5). In this paper, we introduce the cell concept and present cell results under concentrations of between 1 and 67 suns. Some design considerations for the cell front side dependent on texture angle are also discussed.