Ionic liquids improve the long-term stability of perovskite solar cells

Wenzhan Xu; Wenhao Shao; Yuanhao Tang; Chenjian Lin; Hanjun Yang; Yu Ting Yang; Jeong Hui Kim; Gangsan Lee; Prashant Kumar; Kevin R. Pedersen; Aidan H. Coffey; Steven P. Harvey; Kenneth R. Graham; Chenhui Zhu; Kai Zhu; Letian Dou

doi:10.1038/s41560-025-01906-6

Ionic liquids improve the long-term stability of perovskite solar cells

Wenzhan Xu
, Wenhao Shao
, Yuanhao Tang
, Chenjian Lin
, Hanjun Yang
, Yu Ting Yang
, Jeong Hui Kim
, Gangsan Lee
, Prashant Kumar
, Kevin R. Pedersen
, Aidan H. Coffey
, Steven P. Harvey
, Kenneth R. Graham
, Chenhui Zhu
, Kai Zhu
, Letian Dou

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

25 Scopus citations

Abstract

Achieving operational stability in halide perovskite solar cells remains a critical challenge for commercialization. Ionic liquids are promising bulk modifiers, yet their mechanistic role in perovskite crystallization is poorly understood. Here we engineered an ionic liquid, methoxyethoxymethyl-1-methylimidazole chloride (MEM-MIM-Cl), with an ethylene glycol ether side chain that regulates perovskite growth and stabilizes buried interfaces via synergistic interactions with NiO_x. MEM-MIM-Cl induces a novel intermediate phase through chelation with undercoordinated Pb(II), suppressing defects and defect-induced degradation. Solar cells incorporating MEM-MIM-Cl achieved a power conversion efficiency of 25.9% and retained 90% of their initial performance after 1,500 h under continuous 1-sun illumination and 90 °C thermal stress—surpassing prior benchmarks under milder ageing conditions. Furthermore, diurnal cyclic ageing revealed unprecedented fatigue resistance, highlighting the dual role of MEM-MIM-Cl in simultaneously enhancing efficiency and operational resilience. This work elucidates design principles for functional ionic liquids while advancing perovskite photovoltaics towards industrial viability.

Original language	English
Pages (from-to)	209-218
Number of pages	10
Journal	Nature Energy
Volume	11
Issue number	2
DOIs	https://doi.org/10.1038/s41560-025-01906-6
State	Published - Feb 2026

Bibliographical note

Publisher Copyright:
© The Author(s), under exclusive licence to Springer Nature Limited 2025.

Funding

This work was primarily supported by First Solar Inc. Y.T. and L.D. acknowledge funding support from the US Department of Energy’s (DOE) Office of Energy Efficiency and Renewable Energy under award nos. DE-EE0009519 and DE-EE0010734. This work was also authored in part by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the US Department of Energy under contract no. DE-AC36-08GO28308. K.Z. and S.P.H. acknowledge support from the HydroGEN Advanced Water Splitting Materials Consortium, established as part of the Energy Materials Network under the US Department of Energy, Office of Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office. The views expressed in the article do not necessarily represent the views of the DOE or the US government. The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for US government purposes.

Funders	Funder number
National Renewable Energy Laboratory
First Solar, Inc.
US Government or NYU
Office of Energy Efficiency and Renewable Energy	DE-EE0010734, DE-EE0009519
U.S. Department of Energy	DE-AC36-08GO28308

UN SDGs

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

SDG 7 Affordable and Clean Energy

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Renewable Energy, Sustainability and the Environment
Fuel Technology
Energy Engineering and Power Technology

Access to Document

10.1038/s41560-025-01906-6

Cite this

@article{62e647d6c1f548e7891cabde876a8392,

title = "Ionic liquids improve the long-term stability of perovskite solar cells",

abstract = "Achieving operational stability in halide perovskite solar cells remains a critical challenge for commercialization. Ionic liquids are promising bulk modifiers, yet their mechanistic role in perovskite crystallization is poorly understood. Here we engineered an ionic liquid, methoxyethoxymethyl-1-methylimidazole chloride (MEM-MIM-Cl), with an ethylene glycol ether side chain that regulates perovskite growth and stabilizes buried interfaces via synergistic interactions with NiOx. MEM-MIM-Cl induces a novel intermediate phase through chelation with undercoordinated Pb(II), suppressing defects and defect-induced degradation. Solar cells incorporating MEM-MIM-Cl achieved a power conversion efficiency of 25.9\% and retained 90\% of their initial performance after 1,500 h under continuous 1-sun illumination and 90 °C thermal stress{\textemdash}surpassing prior benchmarks under milder ageing conditions. Furthermore, diurnal cyclic ageing revealed unprecedented fatigue resistance, highlighting the dual role of MEM-MIM-Cl in simultaneously enhancing efficiency and operational resilience. This work elucidates design principles for functional ionic liquids while advancing perovskite photovoltaics towards industrial viability.",

author = "Wenzhan Xu and Wenhao Shao and Yuanhao Tang and Chenjian Lin and Hanjun Yang and Yang, \{Yu Ting\} and Kim, \{Jeong Hui\} and Gangsan Lee and Prashant Kumar and Pedersen, \{Kevin R.\} and Coffey, \{Aidan H.\} and Harvey, \{Steven P.\} and Graham, \{Kenneth R.\} and Chenhui Zhu and Kai Zhu and Letian Dou",

note = "Publisher Copyright: {\textcopyright} The Author(s), under exclusive licence to Springer Nature Limited 2025.",

year = "2026",

month = feb,

doi = "10.1038/s41560-025-01906-6",

language = "English",

volume = "11",

pages = "209--218",

journal = "Nature Energy",

issn = "2058-7546",

publisher = "Springer Nature",

number = "2",

}

TY - JOUR

T1 - Ionic liquids improve the long-term stability of perovskite solar cells

AU - Xu, Wenzhan

AU - Shao, Wenhao

AU - Tang, Yuanhao

AU - Lin, Chenjian

AU - Yang, Hanjun

AU - Yang, Yu Ting

AU - Kim, Jeong Hui

AU - Lee, Gangsan

AU - Kumar, Prashant

AU - Pedersen, Kevin R.

AU - Coffey, Aidan H.

AU - Harvey, Steven P.

AU - Graham, Kenneth R.

AU - Zhu, Chenhui

AU - Zhu, Kai

AU - Dou, Letian

PY - 2026/2

Y1 - 2026/2

N2 - Achieving operational stability in halide perovskite solar cells remains a critical challenge for commercialization. Ionic liquids are promising bulk modifiers, yet their mechanistic role in perovskite crystallization is poorly understood. Here we engineered an ionic liquid, methoxyethoxymethyl-1-methylimidazole chloride (MEM-MIM-Cl), with an ethylene glycol ether side chain that regulates perovskite growth and stabilizes buried interfaces via synergistic interactions with NiOx. MEM-MIM-Cl induces a novel intermediate phase through chelation with undercoordinated Pb(II), suppressing defects and defect-induced degradation. Solar cells incorporating MEM-MIM-Cl achieved a power conversion efficiency of 25.9% and retained 90% of their initial performance after 1,500 h under continuous 1-sun illumination and 90 °C thermal stress—surpassing prior benchmarks under milder ageing conditions. Furthermore, diurnal cyclic ageing revealed unprecedented fatigue resistance, highlighting the dual role of MEM-MIM-Cl in simultaneously enhancing efficiency and operational resilience. This work elucidates design principles for functional ionic liquids while advancing perovskite photovoltaics towards industrial viability.

AB - Achieving operational stability in halide perovskite solar cells remains a critical challenge for commercialization. Ionic liquids are promising bulk modifiers, yet their mechanistic role in perovskite crystallization is poorly understood. Here we engineered an ionic liquid, methoxyethoxymethyl-1-methylimidazole chloride (MEM-MIM-Cl), with an ethylene glycol ether side chain that regulates perovskite growth and stabilizes buried interfaces via synergistic interactions with NiOx. MEM-MIM-Cl induces a novel intermediate phase through chelation with undercoordinated Pb(II), suppressing defects and defect-induced degradation. Solar cells incorporating MEM-MIM-Cl achieved a power conversion efficiency of 25.9% and retained 90% of their initial performance after 1,500 h under continuous 1-sun illumination and 90 °C thermal stress—surpassing prior benchmarks under milder ageing conditions. Furthermore, diurnal cyclic ageing revealed unprecedented fatigue resistance, highlighting the dual role of MEM-MIM-Cl in simultaneously enhancing efficiency and operational resilience. This work elucidates design principles for functional ionic liquids while advancing perovskite photovoltaics towards industrial viability.

UR - https://www.scopus.com/pages/publications/105031061805

UR - https://www.scopus.com/pages/publications/105031061805#tab=citedBy

U2 - 10.1038/s41560-025-01906-6

DO - 10.1038/s41560-025-01906-6

M3 - Article

AN - SCOPUS:105031061805

SN - 2058-7546

VL - 11

SP - 209

EP - 218

JO - Nature Energy

JF - Nature Energy

IS - 2

ER -

Ionic liquids improve the long-term stability of perovskite solar cells

Abstract

Bibliographical note

Funding

UN SDGs

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this