Laser Chemical Processing (LCP) Doping Formed through Different Dielectric Layers

Laser chemical processing (LCP) has been proven to be an effective technology to form selective emitters and local back surface fields for high efficiency silicon solar cells. In this work, LCP n-type doping formed through different dielectric layers is presented, and is characterisaed by changes in the effective lifetime (eff) and emitter saturation current density (Joe). With the same LCP parameters, the sheet resistance of the n-type doping area could be made as low as 15-20 Ω/ under various passivation layers. As the doping area fraction increases, we observe clear degradation in eff and Joe with different passivation layers. Under the same LCP parameters and doping fraction, SiO2 passivated samples show a reduced eff and Joe degradation than those pssivated by SiNx. The reason could be attributed to the different thermal properties of SiO2 and SiNx dielectric layers and the passivation effects of the H3PO4 doping solution on the Si-SiO2 interface.

28th European Photovoltaic Solar Energy Conference and Exhibition; 1057-1060