TY - CONF

T1 - Laser technology for cost reduction in silicon solar cell production

AU - Schoonderbeek, Aart

AU - Stute, Uwe

AU - Ostendorf, Andreas

AU - Grischke, Rainer

AU - Engelhart, Peter

AU - Meyer, Rüdiger

AU - Brendel, Rolf

N1 - Funding Information: This work was supported by the State of Lower Saxony/Germany, which we gratefully acknowledge.

PY - 2006

Y1 - 2006

N2 - During the last years, the photovoltaic solar cell industry has experienced enormous growth. However, for solar cells to be competitive on the longer term, both an increase in their efficiency as well as a reduction in their cost is necessary. This paper discusses some opportunities of laser technology to realize these improvements. An effective method to reduce costs of silicon solar cells is reducing the wafer thickness, because silicon causes a large part of the costs. Consequently, for applying the emitter contact fingers on the solar cell, contact free laser processing has a large advantage in contrast to commonly used print screen techniques. This is because of less scrap due to broken wafers. Additional, many novel high efficiency solar cell concepts are only feasible with laser technology, e.g. due to the requirement for drilling a few thousand holes per second in brittle materials. In this paper, experimental investigations are discussed for producing grooves and holes in silicon wafers according to a recently developed solar cell concept. The amount of heat affected silicon in the surrounding of the processing is minimized. Any unavoidable heat affected material and debris is subsequently removed with a chemical etching process. Laser processing is studied with a variety of pulsed laser sources like excimer lasers, Nd:YAG lasers and frequency converted solid state lasers with a variety of wavelengths. Furthermore, different types of lasers are compared regarding their processing quality and processing time.

AB - During the last years, the photovoltaic solar cell industry has experienced enormous growth. However, for solar cells to be competitive on the longer term, both an increase in their efficiency as well as a reduction in their cost is necessary. This paper discusses some opportunities of laser technology to realize these improvements. An effective method to reduce costs of silicon solar cells is reducing the wafer thickness, because silicon causes a large part of the costs. Consequently, for applying the emitter contact fingers on the solar cell, contact free laser processing has a large advantage in contrast to commonly used print screen techniques. This is because of less scrap due to broken wafers. Additional, many novel high efficiency solar cell concepts are only feasible with laser technology, e.g. due to the requirement for drilling a few thousand holes per second in brittle materials. In this paper, experimental investigations are discussed for producing grooves and holes in silicon wafers according to a recently developed solar cell concept. The amount of heat affected silicon in the surrounding of the processing is minimized. Any unavoidable heat affected material and debris is subsequently removed with a chemical etching process. Laser processing is studied with a variety of pulsed laser sources like excimer lasers, Nd:YAG lasers and frequency converted solid state lasers with a variety of wavelengths. Furthermore, different types of lasers are compared regarding their processing quality and processing time.

UR - http://www.scopus.com/inward/record.url?scp=56749164784&partnerID=8YFLogxK

U2 - 10.2351/1.5060907

DO - 10.2351/1.5060907

M3 - Paper

AN - SCOPUS:56749164784

T2 - ICALEO 2006 - 25th International Congress on Applications of Laser and Electro-Optics

Y2 - 30 October 2006 through 2 November 2006

ER -