Progress in Laser Chemical Processing (LCP) for innovative solar cell microstructuring and wafering applications

In this paper we report progress in Laser Chemical Processing (LCP) wafering and microstructuring applications. The LCP method was formerly known as Laser Chemical Etching (LCE) and has now been extended to further applications as laser doping e.g. Fundamental experiments show that damage-free silicon removal in one single LCP step is possible without the need of damage-etching. Additionally, the wafering proof-of-concept could be obtained in terms of 7 centimeter deep cutting, competitive initial cutting speeds and encouraging low energy consumption compared to the multi-wire slurry saw. Two microstructuring applications are investigated: The edge isolation and the selective emitter formation using a phosphorous containing liquid as the dopant source. We present the first solar cell results with selective LCP emitter showing that LCP can introduce a local selective emitter into a shallow industrial emitter without negative impact on the recombination in the space charge region.