Mechanisch texturierte, grossflächige, multikristalline Siliziumsolarzellen

Abstract

In this work on one hand a process sequence for industrial type multicrystalline silicon solar cells was developed and on the other hand the gain in efficiency due to applying a mechanically formed V texturisation was investigated.Key features of the process are the bulk and surface passivation by Plasma Enhanced Chemical Vapor Deposition (PECVD) SiNx and Al-Back Surface Field (BSF). Applying this process to standard casted multicrystalline Si wafer an average efficiency clearly above 14 have been achieved.The efficiency enhancement of V-textured solar cells compared to alkaline etched solar cells was estimated to be 3 relative using computer simulation. Investigation of the industrial application of mechanical V-texturing itself and adaptation of the solar cell process include the life-time of the tool, the yield, depth and angle of the V-profile as well as screen printed metallisation.In the production line of Q-Cells AG mechanically V - textured multicrystalline solar cells were processed showing an average efficiency of 15,5 (50 cells, 156cm2). A 36 cell module fabricated from theses cells exhibits a module power of 85 Wp.Incorporating the experience with the homogeneous emitter process, a advanced processing sequence applying a selective emitter was developed which leads to a maximum efficiency of 16,2 (cell size 12,4cm x 12,4 cm) in the pilot line of University of Konstanz..