Improvement of multicrystalline silicon solar cells by a low temperature anneal after emitter diffusion

• Published in: Progress in photovoltaics Vol. 19; no. 2; pp. 165 - 169
• Main Authors: Rinio, Markus, Yodyunyong, Arthit, Keipert-Colberg, Sinje, Mouafi, Yves Patrick Botchak, Borchert, Dietmar, Montesdeoca-Santana, Amada
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.03.2011; Wiley
• Subjects: Annealing; Applied sciences; Diffusion; Diffusion annealing; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Emittance; Energy; Exact sciences and technology; gettering; iron; LBIC; multicrystalline; Natural energy; Photoelectric conversion; Photovoltaic cells; Photovoltaic conversion; Silicon; solar cell processing; Solar cells; Solar cells. Photoelectrochemical cells; Solar energy; Walls; Solar cell; Crystalline material; Silicon solar cells; Annealing; Heat treatment; LBIC; multicrystalline; Transmitter; Iron; Gettering; solar cell processing; Low temperature
• ISSN: 1062-7995; 1099-159X; 1099-159X
• DOI: 10.1002/pip.1002

The influence of an annealing step at about 500 °C after emitter diffusion of multicrystalline solar cells is investigated. Neighboring wafers from a silicon ingot were processed using different annealing durations and temperatures. The efficiency of the cells was measured and detailed light beam induced current measurements were performed. These show that mainly areas with high contents of precipitates near the crucible walls are affected by the anneal. An efficiency increase from 14.5 to 15.4% by a 2 h anneal at 500 °C was observed. The effect seems to be more likely external than internal gettering. Copyright © 2010 John Wiley & Sons, Ltd. An annealing step of 500 ‐ 600 °C for about 1 – 2 hours after phosphorus diffusion improves the border areas of multicrystalline silicon solar cells that were deteriorated from the crucible. Light beam induced current topograms indicate that the effect can be explained by phosphorus gettering. An efficiency increase from 14.5 % to 15.4 % by a 2 hour anneal at 500 °C was observed.