Spatially modulating the fluorescence color of mixed-halide perovskite nanoplatelets through direct femtosecond laser writing

Chunhua Zhou, Guiyuan Cao, Zhixing Gan, Qingdong Ou, Weijian Chen, Qiaoliang Bao, Baohua Jia, Xiaoming Wen

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29 Citations (Scopus)


Lead halide perovskites are widely applied in not only photovoltaics but also on-chip light sources and photon detection. To promote the incorporation of perovskite into integrated devices, microscale color patterning flexibility is a very important step. Here, we demonstrate spatially resolved modulation of the fluorescence of nanoplatelets (NPs) by femtosecond direct laser writing (fs-DLW). As the perovskite NP for the fs-DLW pattern is specially designed with a gradual bromide-iodide composition along the depth, the replacement of iodide ions by bromide ions can be activated under a controlled laser pulse and fluorescence is thus modulated from red to green. The effect of processing depth and NP thickness on fluorescence modulation is systemically investigated. The as-grown thick NP (thickness ≈ 500 nm) mainly exhibits a 690 nm emission from the bottom iodine-rich phase. After halide substitution induced by fs-DLW, a new fluorescence peak appears in the wavelength range of 540-600 nm; the peak position and intensity are controlled by the DLW conditions. The fluorescent color is spatially modulated from red to green, enabling microscale-resolved multicolor emission. Compared with other currently available techniques, microscale color patterning via fs-DLW is a straightforward mask-free one-step operation, yielding high spatial resolution and enabling three-dimensional patterning by the multiple-photon method. We demonstrate that arbitrary patterns can be drawn on a wide range of perovskite NPs, implying the potential applications in microencryption, sensors, multicolor displays, lasers, and light-emitting devices.

Original languageEnglish
Pages (from-to)26017-26023
Number of pages7
JournalACS Applied Materials & Interfaces
Issue number29
Publication statusPublished - 24 Jul 2019


  • direct laser writing
  • femtosecond laser fabrication
  • fluorescence
  • gradient band gap
  • mixed-halide perovskites

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