Complex formation of ferrocene derivatives with electron transport layers enables improved performance and photostability in organic solar cells

Patipan Sukpoonprom; William D.J. Tremlett; Zhuoran Qiao; Chitsanucha Chattakoonpaisarn; Eunyoung Hong; Beier Hu; Karen Forberich; Jianhua Han; Junyi Wang; Somlak Ittisanronnachai; Longren Li; Francesco Vanin; Pichaya Pattanasattayavong; Zonglong Zhu; Artem Bakulin; Christoph J. Brabec; Derya Baran; Nicholas J. Long; Nicola Gasparini

doi:10.1016/j.joule.2025.102107

Complex formation of ferrocene derivatives with electron transport layers enables improved performance and photostability in organic solar cells

Patipan Sukpoonprom (Co-first Author)
, William D.J. Tremlett (Co-first Author)
, Zhuoran Qiao (Co-first Author)
, Chitsanucha Chattakoonpaisarn
, Eunyoung Hong
, Beier Hu
, Karen Forberich
, Jianhua Han
, Junyi Wang
, Somlak Ittisanronnachai
, Longren Li
, Francesco Vanin
, Pichaya Pattanasattayavong
, Zonglong Zhu
, Artem Bakulin
, Christoph J. Brabec
, Derya Baran
, Nicholas J. Long^*
, Nicola Gasparini^*

^*Corresponding author for this work

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

5 Citations (Scopus)

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Abstract

Electron transport layers (ETLs), e.g., metal oxides, organic small molecules, or conjugated polymers, play a vital role in both performance and photo-thermal stability in organic solar cells (OSCs). Herein, we explored hybrid organic-inorganic electron transport materials by forming complexes between typical electron transport layers and ferrocene (Fc)-based molecules. Experimental and theoretical investigations revealed van der Waals interaction between the ETL and Fc compounds, which allows fine-tuning of the electrode work function to improve charge extraction properties and reduce trap-assisted recombination. As a result, OSCs showed improved fill factor (FF) and power conversion efficiency (PCE) for five donor-acceptor blends and three ETLs, with FF and PCE exceeding 80% and 20.1%, respectively. Finally, we demonstrated improved photostability for the hybrid ETLs with devices that retained 80% of their initial performance for 700 h when degraded under operating conditions (ISOS-L-1I). © 2025 The Author(s).

Original language	English
Article number	102107
Number of pages	13
Journal	Joule
Volume	9
Issue number	10
Online published	5 Sept 2025
DOIs	https://doi.org/10.1016/j.joule.2025.102107
Publication status	Published - 15 Oct 2025

Funding

N.G. thanks the Engineering and Physics Science Research Council (EPSRC) (EP/T028513/1) and the European Union under grant agreement number 101172797. P.P. acknowledges funding support from the National Science, Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources and Institutional Development, Research and Innovation (grant number B49G680107). N.J.L. acknowledges Imperial College London for funding via the Sir Edward Frankland BP Chair endowment, Impact Acceleration Award, and the Deep-Tech Prime program and is also grateful for a Royal Society Wolfson Research Merit award. P.S. acknowledges C. Kaiyasuan for helping with PL measurements.

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 7 Affordable and Clean Energy

Research Keywords

charge extraction
complex formation
efficiency
electron transporting layer
ferrocene
fill factor
low-cost
organic solar cells
organometallic chemistry
stability

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This full text is made available under CC-BY 4.0. https://creativecommons.org/licenses/by/4.0/

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Sukpoonprom, P., Tremlett, W. D. J., Qiao, Z., Chattakoonpaisarn, C., Hong, E., Hu, B., Forberich, K., Han, J., Wang, J., Ittisanronnachai, S., Li, L., Vanin, F., Pattanasattayavong, P., Zhu, Z., Bakulin, A., Brabec, C. J., Baran, D., J. Long, N., & Gasparini, N. (2025). Complex formation of ferrocene derivatives with electron transport layers enables improved performance and photostability in organic solar cells. Joule, 9(10), Article 102107. https://doi.org/10.1016/j.joule.2025.102107

@article{dde85307e5674d0f95041faa4c5279ef,

title = "Complex formation of ferrocene derivatives with electron transport layers enables improved performance and photostability in organic solar cells",

abstract = "Electron transport layers (ETLs), e.g., metal oxides, organic small molecules, or conjugated polymers, play a vital role in both performance and photo-thermal stability in organic solar cells (OSCs). Herein, we explored hybrid organic-inorganic electron transport materials by forming complexes between typical electron transport layers and ferrocene (Fc)-based molecules. Experimental and theoretical investigations revealed van der Waals interaction between the ETL and Fc compounds, which allows fine-tuning of the electrode work function to improve charge extraction properties and reduce trap-assisted recombination. As a result, OSCs showed improved fill factor (FF) and power conversion efficiency (PCE) for five donor-acceptor blends and three ETLs, with FF and PCE exceeding 80\% and 20.1\%, respectively. Finally, we demonstrated improved photostability for the hybrid ETLs with devices that retained 80\% of their initial performance for 700 h when degraded under operating conditions (ISOS-L-1I). {\textcopyright} 2025 The Author(s).",

keywords = "charge extraction, complex formation, efficiency, electron transporting layer, ferrocene, fill factor, low-cost, organic solar cells, organometallic chemistry, stability",

author = "Patipan Sukpoonprom and Tremlett, \{William D.J.\} and Zhuoran Qiao and Chitsanucha Chattakoonpaisarn and Eunyoung Hong and Beier Hu and Karen Forberich and Jianhua Han and Junyi Wang and Somlak Ittisanronnachai and Longren Li and Francesco Vanin and Pichaya Pattanasattayavong and Zonglong Zhu and Artem Bakulin and Brabec, \{Christoph J.\} and Derya Baran and \{J. Long\}, Nicholas and Nicola Gasparini",

year = "2025",

month = oct,

day = "15",

doi = "10.1016/j.joule.2025.102107",

language = "English",

volume = "9",

journal = "Joule",

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Sukpoonprom, P, Tremlett, WDJ, Qiao, Z, Chattakoonpaisarn, C, Hong, E, Hu, B, Forberich, K, Han, J, Wang, J, Ittisanronnachai, S, Li, L, Vanin, F, Pattanasattayavong, P, Zhu, Z, Bakulin, A, Brabec, CJ, Baran, D, J. Long, N & Gasparini, N 2025, 'Complex formation of ferrocene derivatives with electron transport layers enables improved performance and photostability in organic solar cells', Joule, vol. 9, no. 10, 102107. https://doi.org/10.1016/j.joule.2025.102107

Complex formation of ferrocene derivatives with electron transport layers enables improved performance and photostability in organic solar cells. / Sukpoonprom, Patipan (Co-first Author); Tremlett, William D.J. (Co-first Author); Qiao, Zhuoran (Co-first Author) et al.
In: Joule, Vol. 9, No. 10, 102107, 15.10.2025.

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

TY - JOUR

T1 - Complex formation of ferrocene derivatives with electron transport layers enables improved performance and photostability in organic solar cells

AU - Sukpoonprom, Patipan

AU - Tremlett, William D.J.

AU - Qiao, Zhuoran

AU - Chattakoonpaisarn, Chitsanucha

AU - Hong, Eunyoung

AU - Hu, Beier

AU - Forberich, Karen

AU - Han, Jianhua

AU - Wang, Junyi

AU - Ittisanronnachai, Somlak

AU - Li, Longren

AU - Vanin, Francesco

AU - Pattanasattayavong, Pichaya

AU - Zhu, Zonglong

AU - Bakulin, Artem

AU - Brabec, Christoph J.

AU - Baran, Derya

AU - J. Long, Nicholas

AU - Gasparini, Nicola

PY - 2025/10/15

Y1 - 2025/10/15

N2 - Electron transport layers (ETLs), e.g., metal oxides, organic small molecules, or conjugated polymers, play a vital role in both performance and photo-thermal stability in organic solar cells (OSCs). Herein, we explored hybrid organic-inorganic electron transport materials by forming complexes between typical electron transport layers and ferrocene (Fc)-based molecules. Experimental and theoretical investigations revealed van der Waals interaction between the ETL and Fc compounds, which allows fine-tuning of the electrode work function to improve charge extraction properties and reduce trap-assisted recombination. As a result, OSCs showed improved fill factor (FF) and power conversion efficiency (PCE) for five donor-acceptor blends and three ETLs, with FF and PCE exceeding 80% and 20.1%, respectively. Finally, we demonstrated improved photostability for the hybrid ETLs with devices that retained 80% of their initial performance for 700 h when degraded under operating conditions (ISOS-L-1I). © 2025 The Author(s).

AB - Electron transport layers (ETLs), e.g., metal oxides, organic small molecules, or conjugated polymers, play a vital role in both performance and photo-thermal stability in organic solar cells (OSCs). Herein, we explored hybrid organic-inorganic electron transport materials by forming complexes between typical electron transport layers and ferrocene (Fc)-based molecules. Experimental and theoretical investigations revealed van der Waals interaction between the ETL and Fc compounds, which allows fine-tuning of the electrode work function to improve charge extraction properties and reduce trap-assisted recombination. As a result, OSCs showed improved fill factor (FF) and power conversion efficiency (PCE) for five donor-acceptor blends and three ETLs, with FF and PCE exceeding 80% and 20.1%, respectively. Finally, we demonstrated improved photostability for the hybrid ETLs with devices that retained 80% of their initial performance for 700 h when degraded under operating conditions (ISOS-L-1I). © 2025 The Author(s).

KW - charge extraction

KW - complex formation

KW - efficiency

KW - electron transporting layer

KW - ferrocene

KW - fill factor

KW - low-cost

KW - organic solar cells

KW - organometallic chemistry

KW - stability

UR - https://www.scopus.com/pages/publications/105016812714

UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-105016812714&origin=recordpage

U2 - 10.1016/j.joule.2025.102107

DO - 10.1016/j.joule.2025.102107

M3 - RGC 21 - Publication in refereed journal

SN - 2542-4351

VL - 9

JO - Joule

JF - Joule

IS - 10

M1 - 102107

ER -

Complex formation of ferrocene derivatives with electron transport layers enables improved performance and photostability in organic solar cells

Abstract

Funding

UN SDGs

Research Keywords

Publisher's Copyright Statement

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