Site‐Selective Bi2Te3 –FeTe2 Heterostructure as a Broadband Saturable Absorber for Ultrafast Photonics
Site‐Selective Bi2Te3 –FeTe2 Heterostructure as a Broadband Saturable Absorber for Ultrafast Photonics
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位点 — 选择性 Bi2Te3 — FeTe2 异质结构作为超快光子学的宽带可饱和吸收体
DOI：
10.1002/lpor.201900409
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发表时间：
2020
影响因子：
11
通讯作者：
Wenjing Zhang
中科院分区：
文献类型：
--
作者：
Linfei Zhang;Jiefeng Liu;Junzi Li;Zhuo Wang;Yingwei Wang;Yanqi Ge;Weilong Dong;Ning Xu;Tingcao He;Han Zhang;Wenjing Zhang
二维（2D）材料具有独特的结构和光电特性，在能源、环境和高性能光电传感领域具有非常重要的应用。其中，非线性光学特性及相关应用是热点研究领域。在此，利用种子介导的生长方法，通过 Fe3+ 诱导和位点选择性过度生长，成功制备了一种新型的二维 Bi2Te3-FeTe2 异质结构。这种异质结构具有板卫星几何形状，具有开放的空间分离表面。 Z扫描测量表征了异质结构的非线性透射率，并通过实验证明了宽带饱和吸收行为，优于一些主流的二维材料。此外，飞秒瞬态吸收光谱显示在 780 nm 泵浦波长下具有 1.7 ps 的超短恢复时间。通过将 Bi2Te3-FeTe2 可饱和吸收体集成到光纤激光器中，可以在中心波长 1064 nm 和 1550 nm 处分别产生 164.7 ps 脉冲和 481 fs 脉冲，这比基于 Bi2Te3 纳米板的锁模效果更好。提供了一种合成具有空间分离结构的二维复合材料的新方法。结果表明，合成的 Bi2Te3-FeTe2 异质结可以成为超快光学应用中很有前景的宽带非线性光学材料。
Two‐dimensional (2D) materials have unique structural and optoelectronic properties and have very important applications in energy, environment, and high‐performance optoelectronic sensing. Among them, the nonlinear optical properties and related applications are hot research fields. Herein, a novel 2D Bi2Te3–FeTe2heterostructure is successfully prepared by Fe3+induction and site‐selective overgrowth using a seed‐mediated growth method. This heterostructure has a plate−satellite geometry with an open spatially separated surface. The Z‐scan measurement characterizes the nonlinear transmittance of the heterostructure and proves the broadband saturation absorption behavior experimentally, which are superior to those of some mainstream 2D materials. In addition, the femtosecond‐transient absorption spectra reveal an ultrashort recovery time of 1.7 ps at pump wavelength of 780 nm. By integrating the Bi2Te3–FeTe2saturable absorber into fiber laser, a 164.7‐ps pulse and a 481‐fs pulse are produced at center wavelengths of 1064 and 1550 nm, respectively, which are better than that of the Bi2Te3nanoplate‐based mode‐locking. A new approach for the synthesis of 2D composites with spatially separated structures is provided. It is demonstrated that the synthesized Bi2Te3–FeTe2heterojunction can be a promising broadband nonlinear optical material in ultrafast optical applications.