Accurate determination of HOMO energies in conjugated diketopyrrolopyrrole-based polymers for predicting the open-circuit voltage of organic photovoltaic devices

Research output: Contribution to conferencePosterAcademic

Abstract

Diketopyrrolopyrrole (DPP) polymers have extensively been used as electron donor materials in organic solar cells. For a diverse set of 19 DPP based polymers we have determined (i) the highest-occupied molecular orbital (HOMO) energies, derived from the oxidation potential as obtained for thin films from square-wave voltammetry (SWV), and (ii) the ionization potential as obtained from ultraviolet photoelectron spectroscopy (UPS), and from density functional theory (DFT) calculations. The empirical relationship obtained from our combined SWV-UPS study between the oxidation and ionization potential shows a slope for DPP polymers which is significantly lower than reported before for other organic semiconductors, while the intercept is the same as reported before. The HOMO energies, that span a range of −5.4 to −4.5 eV, as derived using SWV are found to show an excellent correlation with the open-circuit voltage of optimized solar cells in which the polymer studied forms a blend with PCBM, with deviations of at most 0.1 eV. A weaker correlation was found with the HOMO energies as obtained from UPS and DFT. Hence, the oxidation potential from SQV is a better empirical predictor for the open-circuit of the solar cell.

Conference

ConferenceInternational Conference on Hybrid and Organic Photovoltaics 2018
Abbreviated titleHOPV18
CountrySpain
CityBenidorm
Period28/05/1831/05/18

Fingerprint

Molecular orbitals
Open circuit voltage
Ultraviolet photoelectron spectroscopy
Polymers
Voltammetry
Ionization potential
Oxidation
Density functional theory
Solar cells
Semiconducting organic compounds
Thin films
Electrons
Networks (circuits)

Cite this

@conference{dc21022f43ab4628b2cc2c9f7396c725,
title = "Accurate determination of HOMO energies in conjugated diketopyrrolopyrrole-based polymers for predicting the open-circuit voltage of organic photovoltaic devices",
abstract = "Diketopyrrolopyrrole (DPP) polymers have extensively been used as electron donor materials in organic solar cells. For a diverse set of 19 DPP based polymers we have determined (i) the highest-occupied molecular orbital (HOMO) energies, derived from the oxidation potential as obtained for thin films from square-wave voltammetry (SWV), and (ii) the ionization potential as obtained from ultraviolet photoelectron spectroscopy (UPS), and from density functional theory (DFT) calculations. The empirical relationship obtained from our combined SWV-UPS study between the oxidation and ionization potential shows a slope for DPP polymers which is significantly lower than reported before for other organic semiconductors, while the intercept is the same as reported before. The HOMO energies, that span a range of −5.4 to −4.5 eV, as derived using SWV are found to show an excellent correlation with the open-circuit voltage of optimized solar cells in which the polymer studied forms a blend with PCBM, with deviations of at most 0.1 eV. A weaker correlation was found with the HOMO energies as obtained from UPS and DFT. Hence, the oxidation potential from SQV is a better empirical predictor for the open-circuit of the solar cell.",
author = "R.E.M. Willems and C.H.L. Weijtens and R. Coehoorn and {de Vries}, X. and R.A.J. Janssen",
year = "2018",
month = "2",
day = "21",
language = "English",
note = "International Conference on Hybrid and Organic Photovoltaics 2018, HOPV18 ; Conference date: 28-05-2018 Through 31-05-2018",

}

Accurate determination of HOMO energies in conjugated diketopyrrolopyrrole-based polymers for predicting the open-circuit voltage of organic photovoltaic devices. / Willems, R.E.M.; Weijtens, C.H.L.; Coehoorn, R.; de Vries, X.; Janssen, R.A.J.

2018. Poster session presented at International Conference on Hybrid and Organic Photovoltaics 2018, Benidorm, Spain.

Research output: Contribution to conferencePosterAcademic

TY - CONF

T1 - Accurate determination of HOMO energies in conjugated diketopyrrolopyrrole-based polymers for predicting the open-circuit voltage of organic photovoltaic devices

AU - Willems,R.E.M.

AU - Weijtens,C.H.L.

AU - Coehoorn,R.

AU - de Vries,X.

AU - Janssen,R.A.J.

PY - 2018/2/21

Y1 - 2018/2/21

N2 - Diketopyrrolopyrrole (DPP) polymers have extensively been used as electron donor materials in organic solar cells. For a diverse set of 19 DPP based polymers we have determined (i) the highest-occupied molecular orbital (HOMO) energies, derived from the oxidation potential as obtained for thin films from square-wave voltammetry (SWV), and (ii) the ionization potential as obtained from ultraviolet photoelectron spectroscopy (UPS), and from density functional theory (DFT) calculations. The empirical relationship obtained from our combined SWV-UPS study between the oxidation and ionization potential shows a slope for DPP polymers which is significantly lower than reported before for other organic semiconductors, while the intercept is the same as reported before. The HOMO energies, that span a range of −5.4 to −4.5 eV, as derived using SWV are found to show an excellent correlation with the open-circuit voltage of optimized solar cells in which the polymer studied forms a blend with PCBM, with deviations of at most 0.1 eV. A weaker correlation was found with the HOMO energies as obtained from UPS and DFT. Hence, the oxidation potential from SQV is a better empirical predictor for the open-circuit of the solar cell.

AB - Diketopyrrolopyrrole (DPP) polymers have extensively been used as electron donor materials in organic solar cells. For a diverse set of 19 DPP based polymers we have determined (i) the highest-occupied molecular orbital (HOMO) energies, derived from the oxidation potential as obtained for thin films from square-wave voltammetry (SWV), and (ii) the ionization potential as obtained from ultraviolet photoelectron spectroscopy (UPS), and from density functional theory (DFT) calculations. The empirical relationship obtained from our combined SWV-UPS study between the oxidation and ionization potential shows a slope for DPP polymers which is significantly lower than reported before for other organic semiconductors, while the intercept is the same as reported before. The HOMO energies, that span a range of −5.4 to −4.5 eV, as derived using SWV are found to show an excellent correlation with the open-circuit voltage of optimized solar cells in which the polymer studied forms a blend with PCBM, with deviations of at most 0.1 eV. A weaker correlation was found with the HOMO energies as obtained from UPS and DFT. Hence, the oxidation potential from SQV is a better empirical predictor for the open-circuit of the solar cell.

UR - http://www.nanoge.org/proceedings/HOPV18/5abc7d5b2ce3435bfd1da3c8

M3 - Poster

ER -