A fluorinated polythiophene hole-transport material for efficient and stable perovskite solar cells

Inyoung Jeong, Jea Woong Jo, Seunghwan Bae, Hae Jung Son, Min Jae Ko

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Charge-transport materials for use in highly efficient and stable perovskite solar cells (PSCs) must exhibit energy levels appropriate for high charge selectivity, sufficiently high charge-transport ability for efficient charge collection, and high humidity resistance for long-term device stability. Polythiophenes are a promising class of hole-transport layer (HTL) materials that could satisfy these requirements. However, PSCs fabricated using conventional poly(3-hexylthiophene) (P3HT) HTLs show limited efficiencies of <16% owing to the shallow highest occupied molecular orbital (HOMO) energy level and poor charge extraction ability of P3HT. Herein, we demonstrate that the fluorinated polythiophene derivative FEH is a suitable replacement for P3HT and a promising HTL material for perovskite solar cells. The FEH was found to have a deeper HOMO and exhibit more efficient charge-extraction ability at the perovskite/HTL interface than P3HT. This is attributed to the electron-withdrawing nature of the fluorine atoms in FEH and its ability to form more uniform films on the perovskite layer. Thus, when FEH was employed as the HTL, the corresponding PSC showed an improved efficiency of 18.0% and an enhancement of all device parameters compared with control devices fabricated using P3HT (10.8%) and Spiro-OMeTAD (17.0%) HTLs. Moreover, fluorination on the conjugated backbone of the polymer increases its hydrophobicity, and the resulting hydrophobic surface of the FEH HTL prevents the ingress of water, resulting in an improvement of the long-term stability of the corresponding PSCs under air exposure.

Original languageEnglish
Pages (from-to)1-6
Number of pages6
JournalDyes and Pigments
Volume164
DOIs
StatePublished - 2019 May 1

Fingerprint

Polymers
Molecular orbitals
Perovskite
Electron energy levels
Charge transfer
Fluorination
Fluorine
Hydrophobicity
Atmospheric humidity
Perovskite solar cells
polythiophene
poly(3-hexylthiophene)
Derivatives
Atoms
Electrons
Water
Air
perovskite

Keywords

  • Hole-transport layer
  • Hydrophobicity
  • Perovskite solar cell
  • Polythiophene
  • Stability

Cite this

Jeong, Inyoung ; Jo, Jea Woong ; Bae, Seunghwan ; Son, Hae Jung ; Ko, Min Jae. / A fluorinated polythiophene hole-transport material for efficient and stable perovskite solar cells. In: Dyes and Pigments. 2019 ; Vol. 164. pp. 1-6.
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abstract = "Charge-transport materials for use in highly efficient and stable perovskite solar cells (PSCs) must exhibit energy levels appropriate for high charge selectivity, sufficiently high charge-transport ability for efficient charge collection, and high humidity resistance for long-term device stability. Polythiophenes are a promising class of hole-transport layer (HTL) materials that could satisfy these requirements. However, PSCs fabricated using conventional poly(3-hexylthiophene) (P3HT) HTLs show limited efficiencies of <16{\%} owing to the shallow highest occupied molecular orbital (HOMO) energy level and poor charge extraction ability of P3HT. Herein, we demonstrate that the fluorinated polythiophene derivative FEH is a suitable replacement for P3HT and a promising HTL material for perovskite solar cells. The FEH was found to have a deeper HOMO and exhibit more efficient charge-extraction ability at the perovskite/HTL interface than P3HT. This is attributed to the electron-withdrawing nature of the fluorine atoms in FEH and its ability to form more uniform films on the perovskite layer. Thus, when FEH was employed as the HTL, the corresponding PSC showed an improved efficiency of 18.0{\%} and an enhancement of all device parameters compared with control devices fabricated using P3HT (10.8{\%}) and Spiro-OMeTAD (17.0{\%}) HTLs. Moreover, fluorination on the conjugated backbone of the polymer increases its hydrophobicity, and the resulting hydrophobic surface of the FEH HTL prevents the ingress of water, resulting in an improvement of the long-term stability of the corresponding PSCs under air exposure.",
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A fluorinated polythiophene hole-transport material for efficient and stable perovskite solar cells. / Jeong, Inyoung; Jo, Jea Woong; Bae, Seunghwan; Son, Hae Jung; Ko, Min Jae.

In: Dyes and Pigments, Vol. 164, 01.05.2019, p. 1-6.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - A fluorinated polythiophene hole-transport material for efficient and stable perovskite solar cells

AU - Jeong, Inyoung

AU - Jo, Jea Woong

AU - Bae, Seunghwan

AU - Son, Hae Jung

AU - Ko, Min Jae

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AB - Charge-transport materials for use in highly efficient and stable perovskite solar cells (PSCs) must exhibit energy levels appropriate for high charge selectivity, sufficiently high charge-transport ability for efficient charge collection, and high humidity resistance for long-term device stability. Polythiophenes are a promising class of hole-transport layer (HTL) materials that could satisfy these requirements. However, PSCs fabricated using conventional poly(3-hexylthiophene) (P3HT) HTLs show limited efficiencies of <16% owing to the shallow highest occupied molecular orbital (HOMO) energy level and poor charge extraction ability of P3HT. Herein, we demonstrate that the fluorinated polythiophene derivative FEH is a suitable replacement for P3HT and a promising HTL material for perovskite solar cells. The FEH was found to have a deeper HOMO and exhibit more efficient charge-extraction ability at the perovskite/HTL interface than P3HT. This is attributed to the electron-withdrawing nature of the fluorine atoms in FEH and its ability to form more uniform films on the perovskite layer. Thus, when FEH was employed as the HTL, the corresponding PSC showed an improved efficiency of 18.0% and an enhancement of all device parameters compared with control devices fabricated using P3HT (10.8%) and Spiro-OMeTAD (17.0%) HTLs. Moreover, fluorination on the conjugated backbone of the polymer increases its hydrophobicity, and the resulting hydrophobic surface of the FEH HTL prevents the ingress of water, resulting in an improvement of the long-term stability of the corresponding PSCs under air exposure.

KW - Hole-transport layer

KW - Hydrophobicity

KW - Perovskite solar cell

KW - Polythiophene

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