Journal of Materiomics

Journal of Materiomics

Volume 7, Issue 5, September 2021, Pages 1039-1048
Journal of Materiomics

Surface modification with ionic liquid for efficient CsPbI2Br perovskite solar cells

https://doi.org/10.1016/j.jmat.2021.02.004Get rights and content
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open access

Highlights

  • The ionic liquid ([PEVIM]Cl) is synthesized to modify the CsPbI2Br surface.

  • The mechanisms of improved device performance have been revealed.

  • High performance with power conversion efficiency of 14.19% is obtained.

  • The unencapsulated device exhibits both enhanced thermal and humidity stability.

Abstract

The presence of numerous trap states on the perovskite surface severely affects the performance of inorganic CsPbI2Br perovskite solar cells. Surface modification has been proven to be an effective strategy to passivate the surface trap states of CsPbI2Br perovskite. However, most modifiers behave high volatility and insulation, not enough to further develop the CsPbI2Br solar cells. Herein, an ionic liquid of 1-viny-3-propionate ethyl imidazolium chloride ([PEVIM]Cl) is applied to modify the CsPbI2Br film surface, yielding a compact film with enhanced crystallinity. The surface trap states of CsPbI2Br film are effectively passivated via the interaction between carbonyl group of [PEVIM]Cl and uncoordinated metal cations of CsPbI2Br perovskite, leading to charge recombination suppression and charge transport enhancement. Consequently, the power conversion efficiency (PCE) of [PEVIM]Cl modified CsPbI2Br device is obviously enhanced from 12.49% to 14.19% with an improved open-circuit voltage of 1.160 V. Moreover, the non-encapsulated device presents excellent thermal stability, still maintaining 91% PCE when heated at 85 °C in nitrogen atmosphere for 360 h. Meanwhile, the non-encapsulated device degrades only 11% PCE after stored at 50% relative humidity for 960 h. This simple and efficient approach provides a promising direction to fabricate high-efficiency and stable inorganic perovskite devices.

Keywords

Inorganic perovskites
CsPbI2Br
Ionic liquid
Surface modification
High efficiency

Cited by (0)

Dr. Xuanhua Li received his B.S. degree from Wuhan University of Technology in 2007, and M.S. degree from USTC in 2010. After that, he started his doctoral studies and received a Ph.D. degree at Department of Electrical and Electronic Engineering, University of Hong Kong in 2014. After a short research in the Institute of IntelligentMachines, CAS, he began his career at the Center of Nano Energy Materials, Northwestern Polytechnical University as a professor. His research is focused on synthesis of 2D nanomaterials and novel metal NPs. He is also interested in plasmon-enhanced solar cells, photocatalytic reaction, and optical sensors.

Xingyu Pu received his B.S. degree from Chang’an University in 2018, and he is now a Ph.D. student at Northwestern Polytechnical University under the supervision of Professor Xuanhua Li. His research is focused on perovskite solar cells.

Jian Han received his B.S. degree from Xi’an University of Technology in 2012, and M.S. degree from Xi’an University of Architecture and Technology in 2016. And now, he is pursuing his doctoral degree at Northwestern Polytechnical University under the supervision of Professor Xuanhua Li. His research is focused on solar cells.

Shuangjie Wang received her M.S. degree in School of Applied Chemistry from Northwestern Polytechnical University. She is currently a Ph.D. candidate in Professor Xuanhua Li’s group from The Northwestern Polytechnical University. Her current research focuses on perovskite solar cell and synthesis of nanomaterials.

Hui Zhou received his B.S. degree at Hefei University of Technology, Hefei, China. He started his bachelor degree at Northwestern Polytechnical University under the supervision of Professor Xuanhua Li in 2019. His current research interest is on the solar cells.

Qi Cao received his B.S. degree from North University of China in 2015, and he is now a Ph.D. student at Northwestern Polytechnical University under the supervision of Professor Xiaoqiang Li and Professor Xuanhua Li. His current research is the surface and interface modification of perovskite solar cells.

Jiabao Yang received his B.S. degree from Taiyuan University of Technology in 2018, and he is now a Ph.D. student at Northwestern Polytechnical University under the supervision of Professor Xuanhua Li. His research is focused on perovskite solar cells.

Ziwei He received her B.S. degree from Northeastern University in 2018. Now she is a M. S candidate at School of Materials in Northwestern Ploytechnical University under the supervision of Professor Xuanhua Li. Her research interests focus on solar cells.

Peer review under responsibility of The Chinese Ceramic Society.