FABRICATION AND CHARACTERISATION OF LASER-DOPED REGIONS IN CRYSTALLINE SILICON WAFERS FOR SOLAR CELL APPLICATIONS

Abstract

Currently investigated approaches to increase the efficiency of silicon wafer solar cells often involve employing laser doping techniques to create selective emitters or local back surface fields. This thesis work investigates characterisation and application of laser-doped selective emitters on multicrystalline silicon (multi-Si) wafer solar cells. Firstly, novel characterisations methods are developed to determine the quality (e.g. sheet resistance) of laser doped lines or (small) areas. Secondly, the fundamentals of laser chemical processing are investigated, leading to an optimised parameter range with respect to the doping profile and the minimisation of laser-induced damage. Finally, selective emitter multi-Si solar cells are fabricated with different doping parameters followed by a self-alignment metallisation scheme. The impact of the laser processing conditions on the final solar cell performance is studied in detail. Challenges with laser-doped selective emitters and their metallization on industrial type multi-Si solar cells are identified and possible solutions are given.