High‐Resolution Patterning of 2D Perovskite Films through Femtosecond Laser Direct Writing

Abstract

2D perovskites have been considered as promising candidates for optoelectronic devices due to their good optical and electronic properties compared to 3D perovskites with significantly higher stability. Considering the commercial applications involving displays, image sensors, and fluorescent anti‐counterfeiting labels, the patterning technique of 2D perovskites is urgently required. However, existing patterning approaches still have challenges in high‐resolution fabrication. Here, a facile femtosecond laser direct writing method to fabricate arbitrarily patterned 2D perovskite films with well‐defined profiles and uniform fluorescence properties is developed. The flexible, fine, and non‐thermal diffused patterning abilities of femtosecond laser facilitate diverse 2D perovskite patterns exhibiting bright emission without any pinholes and cracks, as well as high resolution of approximate 2 µm line width. Based on this efficient patterning technique, this study demonstrates fluorescent anti‐counterfeiting labels (quick response code embedded with microlines) based on 2D perovskite films with high humidity stability, which can be identified from 43% to 96% relative humidity. This high‐resolution, reliable, efficient, and facile patterning technique for 2D perovskites with high humidity stability provides a promising technical route for 2D perovskite‐based optoelectronic applications.

Multicolor Display Fabricated via Stacking CW Laser-Patterned Perovskite Films

“…To date, direct patterning by an ultrafast laser has been demonstrated to be an effective technique for spatiotemporally micromachining and engineering materials. − As a noncontact method, an ultrafast laser can directly ablate object materials and increase photothermal energy in local areas, thereby inducing chemical reactions in local positions. − Qiu and Dong reported that a femtosecond laser (fs) laser could inject energy with an ultrashort amount of time, which leads to strong thermal accumulation and thereby increases the local pressure and temperature (>2500 °C) above the liquidus of glass composition, so that the crystallization of perovskite nanoparticles (NPs) inside the glassy matrix is realized. , Zhizhchenko et al produced donut-shaped MAPbI 3 whispering-gallery mode microlasers by utilizing the fs laser to remove selective regions of MAPbI 3 films via thermal ablation . The reported ultrafast laser-patterned microstructures mainly rely on thermal ablation by direct laser energy deposition; however, the undesirable crystallizations and cracks in the adjacently focused areas are inevitable, limiting the resolution of the patterned perovskite.…”

Nanoarchitectonics and Applications of Gallium‐Based Liquid Metal Micro‐ and Nanoparticles

“…The advantages of using laser to sinter GLM micro-nanoparticles are as follows: First and foremost, high efficiency and accuracy: Laser is often used to efficiently fabricate high-resolution micro/nano structures. [66][67][68][69][70][71][72] Therefore, using laser sintering can ensure high accuracy and efficiency in the sintering process. What's more, uniform sintering energy distribution: laser sintering can form uniform oxide film, thus ensuring the stability of the conductivity of the sintering circuit.…”

Photo-processing of perovskites: current research status and challenges

“…7) For the optical storage, display and photodetector applications, the dot size is still too large (typically larger than several micrometers). Decreasing the dot size is necessary for high-capacity data storage, high-resolution display and highly sensitive photodetectors in the future 136 . The dot size is generally determined by the thermal diffusion and diffraction limit.…”