MODELLING OF SILICON SOLAR CELLS BY USING AN EXTENDED TWO-DIODE-MODEL APPROACH

摘要

The present work is related to effects originating from the spatial character and therefore referring tothe distributed resistance of a silicon solar cell. Two effects are regarded: Firstly, the bending of the illuminated IVcurveparticular at open-circuit-conditions towards a lower voltage due to an increased metal/emitter resistance.Secondly, enhanced fill factor losses due to lateral current paths in case of back contact solar cells. A simple approachis presented by taking into account a second one-diode-model in addition to a conventional standalone one-diodemodel.The key idea is simple: By separating these models by a resistor, diodes are forward biased differently as it isthe case in real operation conditions and internal current flow leads to a distortion of the measurable global IV-curve.We show that results achieved by the so called “distributed-two-diode-model” give already comparable results to farmore complex two-dimensional finite element simulations utilizing Sentaurus TCAD.