Selective emitters in buried contact silicon solar cells: Some low-cost solutions

We present the results of our study on the formation of selective emitter s tructures in buried contact cells. In particular, our attention has been fo cused on those processes that seem to be scalable to industry. To this aim, specific dopant sources and fabrication steps have been selected. Two different kinds of dopants have been considered: the P-doped SOD and th e screenprinted dopant paste. For both sources we have tested the feasibili ty of the selective diffusion formation in a single step, together with the application of suitable techniques to get selective doping, such as laser enhanced diffusion into the grooves, or selective deposition of screen prin ted paste in buried grid pattern. SEM and SEM-EBIC analyses have been used to investigate the occurrence of doping. Several batches of buried contact, mechanically grooved cells have prepared and tested. (C) 2001 Elsevier Sci ence B.V. All rights reserved.