Laser Chemical Processing (LCP) of Poly-Silicon Thin Film

Abstract

Laser chemical processing (LCP), developed by Fraunhofer Institute for Solar Energy Systems was successfully applied in fabricating n-type selective emitters and p-type local back surface fields for bulk crystalline silicon wafer solar cells. In this thesis, LCP is demonstrated as a straightforward technique for laser doping of poly-silicon (poly-Si) thin films, thereby overcoming the process complexity related to laser doping on thin films as well as supplying a practically infinite amount of dopants during the doping process. Using a frequency-doubled (532 nm) tunable nanosecond Nd:YAG laser coupled inside a phosphoric acid jet, LCP was successfully applied in fabricating an n-type active layer for poly-silicon thin film solar cells on glass.