Extraction of individual components of series resistance using TCAD simulations meeting the requirements of 2- and 3-dimensional carrier flow of IBC solar cells

Abstract

The series resistance (R_S) of a solar cell, that influences fill factor and thus efficiency, is usually decomposed into individual components for development of optimization strategies. In this contribution we introduce a method to extract R_s of each part of the solar cell from TCAD simulation using free energy loss analysis. This method is particularly relevant for modern cell concepts where only TCAD simulation describes correctly high injection phenomena in lowly doped wafers, and where 2- or 3-dimensional carrier flow occurs (PERC, PERT, IBC) invalidating the classical analytical models for Rs description. We compare the lumped R_S value extracted from the FELA to the R_S extracted from the Multiple Light Intensity Method (MLIM) for IBC solar cells with various geometries and wafer doping levels, with and without a front surface field, and show that it is quite accurate even when high injection phenomena induce a slight underestimation of R_S.