skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Exchange current density model for the contact-determined current-voltage behavior of solar cells

Abstract

An analytic expression for the current–voltage [J(V)] behavior of a solar cell as limited by equilibrium exchange current densities of both carriers at both contacts is derived. The partial currents at both contacts to a generic semiconductor absorber are assumed to be linearly proportional to the excess carrier concentration at the interface with the contacts (e.g., as with Schottky-like contacts). The assumption that the quasi-Fermi levels in the absorber are approximately flat leads to an algebraic solution for the applied voltage as a function of current, which is inverted to obtain the analytic J(V) curve. The J(V) curve reveals distinct behavior associated with electrons and holes, separately, and allows for the determination of all critical performance parameters. In particular, it demonstrates how the characteristic features of the J(V) curve depend on the relative rate at which a particular carrier (electron or hole) is collected at one contact vs the other, rather than the relative rate of electron vs hole collection at a single contact. Furthermore, the model provides a unified explanation of how majority carrier extraction limitations cause nonideal J(V) behaviors such as S-shaped curves and dark/light crossover (i.e., failure of superposition). The efficacy and limitations of the model whenmore » applied to Schottky-type and doped semiconductor contacts are discussed. The work serves as a theoretical guide to scientists studying solar cells that are thought to be primarily limited by their contacts.« less

Authors:
 [1];  [1]; ORCiD logo [1]
  1. Univ. of Oregon, Eugene, OR (United States)
Publication Date:
Research Org.:
Univ. of Oregon, Eugene, OR (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1611775
Alternate Identifier(s):
OSTI ID: 1525556
Grant/Contract Number:  
SC0012363
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 125; Journal Issue: 22; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Physics; Schottky diodes; Semiconductors; Thermionic emission; Solar cells; Work functions; Electric currents; Semiconductor structures; P-N junctions; Photovoltaics; Heterostructures

Citation Formats

Roe, Ellis T., Egelhofer, Kira E., and Lonergan, Mark C. Exchange current density model for the contact-determined current-voltage behavior of solar cells. United States: N. p., 2019. Web. doi:10.1063/1.5090519.
Roe, Ellis T., Egelhofer, Kira E., & Lonergan, Mark C. Exchange current density model for the contact-determined current-voltage behavior of solar cells. United States. doi:10.1063/1.5090519.
Roe, Ellis T., Egelhofer, Kira E., and Lonergan, Mark C. Fri . "Exchange current density model for the contact-determined current-voltage behavior of solar cells". United States. doi:10.1063/1.5090519. https://www.osti.gov/servlets/purl/1611775.
@article{osti_1611775,
title = {Exchange current density model for the contact-determined current-voltage behavior of solar cells},
author = {Roe, Ellis T. and Egelhofer, Kira E. and Lonergan, Mark C.},
abstractNote = {An analytic expression for the current–voltage [J(V)] behavior of a solar cell as limited by equilibrium exchange current densities of both carriers at both contacts is derived. The partial currents at both contacts to a generic semiconductor absorber are assumed to be linearly proportional to the excess carrier concentration at the interface with the contacts (e.g., as with Schottky-like contacts). The assumption that the quasi-Fermi levels in the absorber are approximately flat leads to an algebraic solution for the applied voltage as a function of current, which is inverted to obtain the analytic J(V) curve. The J(V) curve reveals distinct behavior associated with electrons and holes, separately, and allows for the determination of all critical performance parameters. In particular, it demonstrates how the characteristic features of the J(V) curve depend on the relative rate at which a particular carrier (electron or hole) is collected at one contact vs the other, rather than the relative rate of electron vs hole collection at a single contact. Furthermore, the model provides a unified explanation of how majority carrier extraction limitations cause nonideal J(V) behaviors such as S-shaped curves and dark/light crossover (i.e., failure of superposition). The efficacy and limitations of the model when applied to Schottky-type and doped semiconductor contacts are discussed. The work serves as a theoretical guide to scientists studying solar cells that are thought to be primarily limited by their contacts.},
doi = {10.1063/1.5090519},
journal = {Journal of Applied Physics},
number = 22,
volume = 125,
place = {United States},
year = {2019},
month = {6}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 2 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

A 720 mV open circuit voltage SiO x : c ‐Si:SiO x double heterostructure solar cell
journal, December 1985

  • Yablonovitch, E.; Gmitter, T.; Swanson, R. M.
  • Applied Physics Letters, Vol. 47, Issue 11
  • DOI: 10.1063/1.96331

Current transport in metal-semiconductor barriers
journal, November 1966


Hole current impedance and electron current enhancement by back-contact barriers in CdTe thin film solar cells
journal, December 2006

  • Pan, Jun; Gloeckler, Markus; Sites, James R.
  • Journal of Applied Physics, Vol. 100, Issue 12
  • DOI: 10.1063/1.2400799

On the Richardson constant of intimate metal-GaAs Schottky barriers
journal, February 1992

  • Missous, M.; Rhoderick, E. H.; Woolf, D. A.
  • Semiconductor Science and Technology, Vol. 7, Issue 2
  • DOI: 10.1088/0268-1242/7/2/007

Contact Selectivity and Efficiency in Crystalline Silicon Photovoltaics
journal, November 2016


Silicon heterojunction solar cell with interdigitated back contacts for a photoconversion efficiency over 26%
journal, March 2017


Limiting efficiency of silicon solar cells
journal, May 1984

  • Tiedje, T.; Yablonovitch, E.; Cody, G.D.
  • IEEE Transactions on Electron Devices, Vol. 31, Issue 5, p. 711-716
  • DOI: 10.1109/T-ED.1984.21594

Role of the Selective Contacts in the Performance of Lead Halide Perovskite Solar Cells
journal, January 2014

  • Juarez-Perez, Emilio J.; Wuβler, Michael; Fabregat-Santiago, Francisco
  • The Journal of Physical Chemistry Letters, Vol. 5, Issue 4, p. 680-685
  • DOI: 10.1021/jz500059v

Tuning Charge Transport at the Interface between Indium Phosphide and a Polypyrrole−Phosphomolybdate Hybrid through Manipulation of Electrochemical Potential
journal, February 2002

  • Daniels-Hafer, Carrie; Jang, Meehae; Boettcher, Shannon W.
  • The Journal of Physical Chemistry B, Vol. 106, Issue 7
  • DOI: 10.1021/jp013022w

Effect of Contacts in Organic Bulk Heterojunction Solar Cells
journal, March 2014


Influence of Surface Recombination on Charge-Carrier Kinetics in Organic Bulk Heterojunction Solar Cells with Nickel Oxide Interlayers
journal, August 2015


Mobility dependent efficiencies of organic bulk heterojunction solar cells: Surface recombination and charge transfer state distribution
journal, July 2009


Effects of the Au/CdTe back contact on IV and CV characteristics of Au/CdTe/CdS/TCO solar cells
journal, March 1997

  • Niemegeers, Alex; Burgelman, Marc
  • Journal of Applied Physics, Vol. 81, Issue 6
  • DOI: 10.1063/1.363946

Effect of temperature and electron irradiation on the I–V characteristics of Au/CdTe Schottky diodes
journal, January 2007


Silicon heterojunction solar cell with passivated hole selective MoO x contact
journal, March 2014

  • Battaglia, Corsin; de Nicolás, Silvia Martín; De Wolf, Stefaan
  • Applied Physics Letters, Vol. 104, Issue 11
  • DOI: 10.1063/1.4868880

Measurement of Richardson constant of GaAs Schottky barriers
journal, February 1981


Limits of Contact Selectivity/Recombination on the Open-Circuit Voltage of a Photovoltaic
journal, February 2018

  • Roe, Ellis T.; Egelhofer, Kira E.; Lonergan, Mark C.
  • ACS Applied Energy Materials, Vol. 1, Issue 3
  • DOI: 10.1021/acsaem.7b00179

Carrier-selective contacts for Si solar cells
journal, May 2014

  • Feldmann, F.; Simon, M.; Bivour, M.
  • Applied Physics Letters, Vol. 104, Issue 18
  • DOI: 10.1063/1.4875904

Open-circuit voltage loss in annealed P3HT:perylene diimide bulk heterojunction solar cells
journal, April 2017

  • Solak, S.; Ricciardulli, A. G.; Lenz, T.
  • Applied Physics Letters, Vol. 110, Issue 16
  • DOI: 10.1063/1.4980842

Detailed balance limit of the efficiency of tandem solar cells
journal, May 1980


Correlated Nonideal Effects of Dark and Light I–V Characteristics in a-Si/c-Si Heterojunction Solar Cells
journal, May 2014

  • Chavali, Raghu Vamsi Krishna; Wilcox, John R.; Ray, Biswajit
  • IEEE Journal of Photovoltaics, Vol. 4, Issue 3
  • DOI: 10.1109/JPHOTOV.2014.2307171

Electron-selective contacts via ultra-thin organic interface dipoles for silicon organic heterojunction solar cells
journal, January 2018

  • Reichel, Christian; Würfel, Uli; Winkler, Kristina
  • Journal of Applied Physics, Vol. 123, Issue 2
  • DOI: 10.1063/1.5010937

The role of buffer layers in polymer solar cells
journal, January 2011

  • Po, Riccardo; Carbonera, Chiara; Bernardi, Andrea
  • Energy Environ. Sci., Vol. 4, Issue 2
  • DOI: 10.1039/C0EE00273A

Current transport at the p -InP|poly(pyrrole) interface
journal, July 2001

  • Jones, Frank E.; Daniels-Hafer, Carrie; Wood, Ben P.
  • Journal of Applied Physics, Vol. 90, Issue 2
  • DOI: 10.1063/1.1380220

Relating Charge Transport, Contact Properties, and Recombination to Open-Circuit Voltage in Sandwich-Type Thin-Film Solar Cells
journal, April 2016


Detailed Balance Limit of Efficiency of p‐n Junction Solar Cells
journal, March 1961

  • Shockley, William; Queisser, Hans J.
  • Journal of Applied Physics, Vol. 32, Issue 3, p. 510-519
  • DOI: 10.1063/1.1736034

On the Impact of Contact Selectivity and Charge Transport on the Open-Circuit Voltage of Organic Solar Cells
journal, November 2016

  • Spies, Annika; List, Mathias; Sarkar, Tanmoy
  • Advanced Energy Materials, Vol. 7, Issue 5
  • DOI: 10.1002/aenm.201601750

Determining interface properties limiting open-circuit voltage in heterojunction solar cells
journal, May 2017

  • Brandt, Riley E.; Mangan, Niall M.; Li, Jian V.
  • Journal of Applied Physics, Vol. 121, Issue 18
  • DOI: 10.1063/1.4982752

Selective Interlayers and Contacts in Organic Photovoltaic Cells
journal, May 2011

  • Ratcliff, Erin L.; Zacher, Brian; Armstrong, Neal R.
  • The Journal of Physical Chemistry Letters, Vol. 2, Issue 11
  • DOI: 10.1021/jz2002259

Optimum mobility, contact properties, and open-circuit voltage of organic solar cells: A drift-diffusion simulation study
journal, April 2012


Influence of charge carrier mobility on the performance of organic solar cells
journal, June 2008

  • Deibel, Carsten; Wagenpfahl, Alexander; Dyakonov, Vladimir
  • physica status solidi (RRL) - Rapid Research Letters, Vol. 2, Issue 4
  • DOI: 10.1002/pssr.200802110

Characteristics of In-Substituted CZTS Thin Film and Bifacial Solar Cell
journal, November 2014

  • Ge, Jie; Chu, Junhao; Jiang, Jinchun
  • ACS Applied Materials & Interfaces, Vol. 6, Issue 23
  • DOI: 10.1021/am505980n

Determination of the maximum efficiency solar cell structure
journal, September 1981


Correlation of Built-In Potential and I–V Crossover in Thin-Film Solar Cells
journal, July 2014

  • Moore, James E.; Dongaonkar, Sourabh; Chavali, Raghu Vamsi Krishna
  • IEEE Journal of Photovoltaics, Vol. 4, Issue 4
  • DOI: 10.1109/JPHOTOV.2014.2316364

Upper limit for the conversion of solar energy
journal, April 1980


S-shaped current-voltage characteristics of organic solar devices
journal, September 2010


Application of the superposition principle to solar-cell analysis
journal, March 1979

  • Lindholm, F. A.; Fossum, J. G.; Burgess, E. L.
  • IEEE Transactions on Electron Devices, Vol. 26, Issue 3
  • DOI: 10.1109/T-ED.1979.19400