Continuous Grain-Boundary Functionalization for High-Efficiency Perovskite Solar Cells with Exceptional Stability

Yingxia Zong, Yuanyuan Zhou, Yi Zhang, Zhipeng Li, Lin Zhang, Ming Gang Ju, Min Chen, Shuping Pang, Xiao Cheng Zeng, Nitin P. Padture

Research output: Contribution to journalArticle

56 Scopus citations

Abstract

Here, we sucessfully demonstrate the continuous functionalization of grain boundaries (GBs) in CH3NH3PbI3 (MAPbI3) organic-inorganic halide perovskite (OIHP) thin films with a triblock copolymer that contains rationally selected hydrophilic-hydrophobic-hydrophilic symmetric blocks. The addition of the triblock copolymer into the precursor solution assists in perovskite solution crystallization, resulting in ultrasmooth thin films with GB regions that are continuously functionalized. Tuning of the thickness of the functionalized GBs is realized, leading to MAPbI3 OIHP thin films with simultaneously enhanced optoelectronic properties and environmental (thermal, moisture, and light) stability. The resulting perovskite solar cells show high stabilized efficiency of 19.4%, most of which is retained (92%) upon 480-hr 1-sun illumination. This approach is generic in nature, and it can be extended to a wide range of OIHPs and beyond. Organic-inorganic halide perovskites (OIHPs) are a family of crystalline semiconducting materials that are revolutionizing the field of photovoltaics. The grain boundary (GB) is the most prominent microstructural feature in solution-processed polycrystalline OIHP thin films, and GB chemistry plays a key role in achieving efficient stable perovskite solar cells (PSCs). In this study, we demonstrate the continuous chemical functionalization of GBs in OIHP thin films by using a triblock copolymer that exhibits both hydrophilicity and hydrophobicity. This chemical approach significantly boosts the optoelectronic properties and stability of the OIHP thin films, leading to PSCs with 19.4% efficiency and exceptional stability. The concept of continuous GB functionalization is generic, and it is applicable to a broad range of OIHPs and other polycrystalline materials, representing a new direction in the development of high-performance PSCs and other optoelectronic devices. Grain boundaries in polycrystalline thin films of hybrid perovskites can play a key role in determining the performance and stability of perovskite solar cells. Here, we demonstrate the controlled, continuous grain-boundary functionalization of hybrid perovskite thin films with a rationally selected triblock copolymer with dual hydrophobic-hydrophilic functionalities. This unique grain-boundary structure is responsible for the enhanced optoelectronic properties and environmental stability of these thin films. We also show that the resulting perovskite solar cells are highly efficient and stable.

Original languageEnglish (US)
Pages (from-to)1404-1415
Number of pages12
JournalChem
Volume4
Issue number6
DOIs
StatePublished - Jun 14 2018

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Keywords

  • efficiency
  • functionalization
  • grain boundary
  • perovskite
  • solar cells
  • stability
  • thin films
  • triblock copolymer

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry
  • Environmental Chemistry
  • Chemical Engineering(all)
  • Biochemistry, medical
  • Materials Chemistry

Cite this

Zong, Y., Zhou, Y., Zhang, Y., Li, Z., Zhang, L., Ju, M. G., Chen, M., Pang, S., Zeng, X. C., & Padture, N. P. (2018). Continuous Grain-Boundary Functionalization for High-Efficiency Perovskite Solar Cells with Exceptional Stability. Chem, 4(6), 1404-1415. https://doi.org/10.1016/j.chempr.2018.03.005