Direct synthesis, large-scale integration, and patterning of two-dimensional (2D) quantum materials (e.g., MoS2, WSe2) on flexible and transparent substrates are of high interest for the flexible and conformal device applications. However, the growth temperature (e.g., 850 °C) of the emerging 2D materials in the common gas-phase synthesis methods are well beyond the tolerances limit of flexible substrates, such as polydimethylsiloxane (PDMS). In addition, random nucleation and growth process in most growth systems limits the predicted integration and patterning freedoms. Here, we report a rapid direct laser crystallization and mask-free large-scale patterning of MoS2and WSe2crystals on PDMS substrates. A thin layer of stoichiometric amorphous 2D film is first laser deposited via pulsed laser deposition (PLD) system onto the flexible substrates followed by a controlled crystallization and direct writing process using a tunable nanosecond laser (1064 nm). The influences of pulse duration, number of pulses, and the thickness of the deposited amorphous 2D layer on the crystallization of 2D materials are discussed. Optical spectroscopy and electrical characterizations are performed to confirm the quality of crystallized 2D materials on flexible substrates. This novel method opens up a new opportunity for the crystallization of complex patterns directly from computer-aided design models for the future 2D materials-based wearable, transparent, and flexible devices.

中文翻译：

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柔性基板上二维材料的快速激光纳米制造和直接图案化 – 2DFlex

柔性和透明基板上二维 (2D) 量子材料（例如 MoS2、WSe2）的直接合成、大规模集成和图案化对于柔性和保形器件应用具有重要意义。然而，常见的气相合成方法中新兴二维材料的生长温度（例如 850 °C）远远超出了柔性基板（如聚二甲基硅氧烷 (PDMS)）的容差限制。此外，大多数生长系统中的随机成核和生长过程限制了预测的集成和图案自由度。在这里，我们报告了在 PDMS 衬底上的 MoS2 和 WSe2 晶体的快速直接激光结晶和无掩模大规模图案化。首先通过脉冲激光沉积 (PLD) 系统将化学计量非晶 2D 薄膜薄层沉积到柔性基板上，然后使用可调谐纳秒激光器 (1064 nm) 进行受控结晶和直接写入工艺。讨论了脉冲持续时间、脉冲数和非晶二维沉积层厚度对二维材料结晶的影响。执行光谱学和电学表征以确认柔性基板上结晶 2D 材料的质量。这种新颖的方法为直接从计算机辅助设计模型中结晶复杂图案开辟了新的机会，用于未来基于二维材料的可穿戴、透明和柔性设备。