Flat lenses based on 2D perovskite nanosheets

Ziyu Wang, Tieshan Yang, Yupeng Zhang, Qingdong Ou, Han Lin, Qianhui Zhang, Huanyang Chen, Hui Ying Hoh, Baohua Jia, Qiaoliang Bao

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19 Citations (Scopus)


Ultrathin flat lenses based on metasurfaces or metamaterials have shown great promise in recent years as essential components in nano-optical system, with capability of abrupt changes of light wavefronts. However, such structural designs require complex nanopatterns and a time-consuming nanofabrication process. In this regard, flat lenses are developed based on 2D perovskite nanosheets, using a cost-effective mask-free femtosecond direct laser writing system. The optical properties of the 2D perovskite are rationally adjusted through facile composition engineering as well as thickness-dependent quantum-size confinement. A diffraction theory model is derived to understand the focusing mechanism of the 2D perovskite nanosheets flat lenses. The as-fabricated lenses exploit the tunable material property variations to effectively manipulate not only the amplitude but also the phase of the incident light to focus into a 3D focal spot with a sub-wavelength resolution in the range of 0.5–0.9λ. The results pave the way toward low-cost and large-scale high-resolution imaging applications in the future.

Original languageEnglish
Article number2001388
Number of pages9
JournalAdvanced Materials
Issue number30
Publication statusPublished - 29 Jul 2020


  • diffraction limit
  • flat lenses
  • hybrid perovskites
  • subwavelength focusing

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