A compact equivalent circuit for the dark current-voltage characteristics of nonideal solar cells

Abstract

This paper presents a compact electrical equivalent circuit which describes the dark current-voltage characteristics of nonideal p-n junction solar cells in a wide range of temperatures. The model clearly separates the voltage drop in the junction and bulk regions. It is based on the combination of two exponential mechanisms, shunt and series resistances and space-charge limited current. In order to increase the accuracy of the parameter extraction process, both ln(I-V) and its derivative plots are fitted simultaneously. From the temperature dependence of the extracted parameters, the conduction mechanisms governing the I-V characteristics can be obtained without assuming dominating terms. In addition, the extracted parameters can be related to other electrical magnitudes obtained from such independent measurements as capacitance-voltage measurements (diffusion potential) and illuminated current-voltage characteristics (series resistance and open-circuit voltage). To exemplify the application, a p+ a-SiC:H∕n c-Si solar cell is studied and a number of major physical aspects derived from the analysis of the fitting values are discussed.

A compact J-V model for solar cell to simplify parameter calculation

“…1 shows the variation of model with the measured data for 5 different solar cells. 1,[14][15][16][17] It is observed that the model characteristics like fill factors, maximum power points for all these cells match closely with the measured data. Our model is validated for some of the standard cells and listed in Table I.…”

“…Usually, polynomial equations are preferred to represent the practical J-V characteristics over equivalent circuit representation that involves iterative calculation in parameter extraction. [1][2][3][4][5][6][7] For an illuminated solar cell having parasitic series and shunt resistances, the simplest of the current density-voltage equation called the Single Exponential Model (SEM), 8 which is given as…”

Universality of non-Ohmic shunt leakage in thin-film solar cells

“…8,9,13,18,19 Some equivalent circuits incorporating a parasitic weak diode have also been proposed to account for these nonlinear shunts. [19][20][21] However, these macroscopic, circuit level models cannot account for the microscopic nature of shunt paths. The physical origin of shunt conduction paths have also been explored in the literature.…”

Performance improvement mechanisms of pyramid-like via hole recessed GaAs-based solar cells grown on Si wafer

“…4 shows the equivalent circuit of the solar cells operated at the forward bias voltage, where R s and R sh are the series resistance and the shunt resistance, respectively. The dark current density at the low current level was mainly influenced by the shunt resistance associated with the carrier recombination loss (Pallares et al, 2006;Tseng and Lee, 2012). It could be found that the dark current density at the low current level of the RE-GOS-cell revealed almost identical with that of the SE-GOS-cell.…”