[فيزيائي 2009]

MODELLING THE EFFECTS OF DISTRIBUTED SERIES RESISTANCE ON SUNS-VOC,

http://www.zshare.net/download/79068594906aa387/

[فيزيائي 2009]

ABSTRACT
A simple model based on the simulation of
distributed series resistance effects in solar cells is
presented. This model overcomes limitations of the
standard two-diode model representation of solar cells in
respect to fitting Suns-Voc (m-Voc) and Jsc-Suns curves.
The model results include (i) an improved understanding
of two-dimensional current flows in shunted solar cells, (ii)
the prediction of shunt types from m-Voc curves and
corresponding distributed resistance model fits, (iii) the
insight that lateral current flows in solar cells are
responsible for deviations between Jsc-Suns data and twodiode
model fits in the high illumination range. The
presented approach extends the application range of
Suns-Voc measurements to solar cells which cannot
adequately be described with the two-diode model.

[فيزيائي 2009]

INTRODUCTION
The two-diode model [1-4], which aims at describing
the dark and illuminated I-V characteristics of p-n junction
solar cells, is widely used to extract relevant device
parameters such as the light-induced current density JL,
the shunt resistance Rsh, the lumped series resistance Rs
and the saturation current densities J01 and J02 of the two
diodes (D1 and D2) [1, 5-8]. Two-diode model fits to
experimentally measured Suns-Voc [9] curves are
particularly useful since metal contacts are not required
and the measurements can thus be performed during
early stages of the cell fabrication sequence [6, 8].
However, in many cases this standard model is not
sufficient to understand the characteristics of real devices
due to non-idealities and three-dimensional current flows
within the cells [2, 3, 10]. In this work we use a simple
distributed series resistance (DSR) model to simulate
Suns-Voc, m-Voc and Jsc-Suns [7] curves. We show that
the presented DSR model is able to explain deviations
between measured and two-diode modelled data that are
frequently observed in these measurements.