Contact optimization on cristalline silicon solar cells

Abstract

The present Final Degree Project has been developed in CENER (National Renewable Energy Centre), in particular in the Photovoltaic Solar Energy department. Nowadays, photovoltaic technologies’ main challenge is to increase solar cells’ efficiency while reducing cost. In crystalline silicon, standard Al-BSF (Aluminium Back Surface Field) structure does not constitute an optimal architecture in terms of efficiency. In order to achieve higher conversion efficiency, PERC (Passivated Emitter and Rear Contact) architecture has been developed and started to be used in the industry. It is expected to reach in the following years values of efficiency of up to 23.5 %, never attainable with the standard Al-BSF structure, with which the highest efficiency reached is around 20 %. During the Project, firstly solar cells are processed according to Al-BSF structure and characterized to fix a baseline process. Once this finished, the main focus is to process solar cells with the new PERC architecture. Different experiments varying rear solar cell contact - in particular laser parameters to perform localized contacts and their design - are carried out and characterized in order to find the optimal parameters of this process