Record cell efficiency on industrial multicrystalline silicon by rapid thermal processing

Simultaneous diffusion of phosphorus and aluminum by rapid thermal processing (RTP) in the order of one minute is used to realize emitter and back surface field in a single high temperature step, with controlled surface concentration of the dopant in order to obtain suitable front surface recombination velocities. Carefully controlling the mentioned parameter on industrial multicrystalline silicon (Polix(R) from Photowatt) lead to 16.7% efficient solar cells on a surface of 25 cm/sup 2/. All results are discussed in terms of photoconductivity decay and quantum efficiency analysis.