Determining the photocurrent of individual cells within an organic solar module by LBIC and the filtering approach: Experiments and simulations

Jens Reinhardt, Pälvi Apilo, Birger Zimmermann, Sanna Rousu, Uli Würfel

Research output: Contribution to journal › Article › Scientific › peer-review

6 Citations (Scopus)

Abstract

Light beam induced current (LBIC) measurements of ITO-free organic photovoltaic modules with monolithic series connection are presented. Selective bias illumination is used to extract the light beam generated current from the module. A large variation of the photocurrent is observed among the cells which is unlikely to match the real generated photocurrent. In order to investigate this behavior, a novel approach (filtering approach) is presented in which the photocurrent of the measured cell is reduced while the remaining cells are kept under full illumination. This method enables the detection of the correct photocurrent of each cell and thus to identify the cell which limits the module current if all the cells comprise large parallel resistances. Dark lock-in thermography measurements of the module revealed several shunted cells. In this case the filtering approach overestimates the photocurrent. Numerical simulations of LBIC applied to modules using either selective bias illumination or forward bias voltage were carried out to understand the observed behavior in detail. The results reveal that a reliable detection of the photocurrent is impossible when several cells have rather low parallel resistances. Whereas for selective bias illumination the photocurrent response of the measured cell is an unambiguous function of the cell?s parallel resistance this is not the case for an applied forward bias voltage.
Original languageEnglish
Pages (from-to)157-164
JournalSolar Energy Materials and Solar Cells
Volume134
DOIs
Publication statusPublished - 2015
MoE publication typeA1 Journal article-refereed

Fingerprint

Induced currents
Photocurrents
Lighting
Experiments
Bias voltage
Electric current measurement
Computer simulation

Keywords

  • Organic solar cells
  • Imaging of modules
  • Photocurrent imaging
  • LBIC
  • DLIT
  • Parallel resistance
  • Shunts

Cite this

Reinhardt, Jens ; Apilo, Pälvi ; Zimmermann, Birger ; Rousu, Sanna ; Würfel, Uli. / Determining the photocurrent of individual cells within an organic solar module by LBIC and the filtering approach : Experiments and simulations. In: Solar Energy Materials and Solar Cells. 2015 ; Vol. 134. pp. 157-164.
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abstract = "Light beam induced current (LBIC) measurements of ITO-free organic photovoltaic modules with monolithic series connection are presented. Selective bias illumination is used to extract the light beam generated current from the module. A large variation of the photocurrent is observed among the cells which is unlikely to match the real generated photocurrent. In order to investigate this behavior, a novel approach (filtering approach) is presented in which the photocurrent of the measured cell is reduced while the remaining cells are kept under full illumination. This method enables the detection of the correct photocurrent of each cell and thus to identify the cell which limits the module current if all the cells comprise large parallel resistances. Dark lock-in thermography measurements of the module revealed several shunted cells. In this case the filtering approach overestimates the photocurrent. Numerical simulations of LBIC applied to modules using either selective bias illumination or forward bias voltage were carried out to understand the observed behavior in detail. The results reveal that a reliable detection of the photocurrent is impossible when several cells have rather low parallel resistances. Whereas for selective bias illumination the photocurrent response of the measured cell is an unambiguous function of the cell?s parallel resistance this is not the case for an applied forward bias voltage.",
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author = "Jens Reinhardt and P{\"a}lvi Apilo and Birger Zimmermann and Sanna Rousu and Uli W{\"u}rfel",
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Reinhardt, J, Apilo, P, Zimmermann, B, Rousu, S & Würfel, U 2015, 'Determining the photocurrent of individual cells within an organic solar module by LBIC and the filtering approach: Experiments and simulations', Solar Energy Materials and Solar Cells, vol. 134, pp. 157-164. https://doi.org/10.1016/j.solmat.2014.11.032

Determining the photocurrent of individual cells within an organic solar module by LBIC and the filtering approach : Experiments and simulations. / Reinhardt, Jens; Apilo, Pälvi; Zimmermann, Birger; Rousu, Sanna; Würfel, Uli.

In: Solar Energy Materials and Solar Cells, Vol. 134, 2015, p. 157-164.

Research output: Contribution to journal › Article › Scientific › peer-review

TY - JOUR

T1 - Determining the photocurrent of individual cells within an organic solar module by LBIC and the filtering approach

T2 - Experiments and simulations

AU - Reinhardt, Jens

AU - Apilo, Pälvi

AU - Zimmermann, Birger

AU - Rousu, Sanna

AU - Würfel, Uli

PY - 2015

Y1 - 2015

N2 - Light beam induced current (LBIC) measurements of ITO-free organic photovoltaic modules with monolithic series connection are presented. Selective bias illumination is used to extract the light beam generated current from the module. A large variation of the photocurrent is observed among the cells which is unlikely to match the real generated photocurrent. In order to investigate this behavior, a novel approach (filtering approach) is presented in which the photocurrent of the measured cell is reduced while the remaining cells are kept under full illumination. This method enables the detection of the correct photocurrent of each cell and thus to identify the cell which limits the module current if all the cells comprise large parallel resistances. Dark lock-in thermography measurements of the module revealed several shunted cells. In this case the filtering approach overestimates the photocurrent. Numerical simulations of LBIC applied to modules using either selective bias illumination or forward bias voltage were carried out to understand the observed behavior in detail. The results reveal that a reliable detection of the photocurrent is impossible when several cells have rather low parallel resistances. Whereas for selective bias illumination the photocurrent response of the measured cell is an unambiguous function of the cell?s parallel resistance this is not the case for an applied forward bias voltage.

AB - Light beam induced current (LBIC) measurements of ITO-free organic photovoltaic modules with monolithic series connection are presented. Selective bias illumination is used to extract the light beam generated current from the module. A large variation of the photocurrent is observed among the cells which is unlikely to match the real generated photocurrent. In order to investigate this behavior, a novel approach (filtering approach) is presented in which the photocurrent of the measured cell is reduced while the remaining cells are kept under full illumination. This method enables the detection of the correct photocurrent of each cell and thus to identify the cell which limits the module current if all the cells comprise large parallel resistances. Dark lock-in thermography measurements of the module revealed several shunted cells. In this case the filtering approach overestimates the photocurrent. Numerical simulations of LBIC applied to modules using either selective bias illumination or forward bias voltage were carried out to understand the observed behavior in detail. The results reveal that a reliable detection of the photocurrent is impossible when several cells have rather low parallel resistances. Whereas for selective bias illumination the photocurrent response of the measured cell is an unambiguous function of the cell?s parallel resistance this is not the case for an applied forward bias voltage.

KW - Organic solar cells

KW - Imaging of modules

KW - Photocurrent imaging

KW - LBIC

KW - DLIT

KW - Parallel resistance

KW - Shunts

U2 - 10.1016/j.solmat.2014.11.032

DO - 10.1016/j.solmat.2014.11.032

M3 - Article

VL - 134

SP - 157

EP - 164

JO - Solar Energy Materials and Solar Cells

JF - Solar Energy Materials and Solar Cells

SN - 0927-0248

ER -

Reinhardt J, Apilo P, Zimmermann B, Rousu S, Würfel U. Determining the photocurrent of individual cells within an organic solar module by LBIC and the filtering approach: Experiments and simulations. Solar Energy Materials and Solar Cells. 2015;134:157-164. https://doi.org/10.1016/j.solmat.2014.11.032

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