Layer-Tunable Nonlinear Optical Characteristics and Photocarrier Dynamics of 2D PdSe2 in Broadband Spectra.
Layer-Tunable Nonlinear Optical Characteristics and Photocarrier Dynamics of 2D PdSe2 in Broadband Spectra.
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DOI：
10.1002/smll.202103938
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发表时间：
2021-10
期刊：
影响因子：
13.3
通讯作者：
Chenyu Ye;Zhen-ju Yang;J. Dong;Yongfeng Huang;Miaomiao Song;B. Sa;Jingying Zheng;Hongbing Zhan
中科院分区：
文献类型：
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作者：
Chenyu Ye;Zhen-ju Yang;J. Dong;Yongfeng Huang;Miaomiao Song;B. Sa;Jingying Zheng;Hongbing Zhan
二维层状过渡金属二硫属化合物（TMDC）具有迷人的非线性光学（NLO）特性，可用于构建各种有前途的光电子器件。然而，探索具有上级非线性吸收和宽带光谱超快响应的所需二维材料仍然是收获其最大潜力的关键挑战。在这里，基于合成具有受控层数的2D PdSe 2薄膜，作者系统地展示了这种新兴材料在飞秒可见-近红外激光脉冲激发（400-1550 nm）下的宽带巨非线性光学性能和超快激发载流子动力学。层依赖性和波长依赖性的光学带隙，非线性吸收，并在所获得的二维PdSe 2的光生载流子动力学的演变清楚地揭示。特别地，从半导体到半金属PdSe 2的转变引起了它们的带间吸收-弛豫过程的急剧变化。这项工作使2D PdSe 2在未来的超快光子学中更具竞争力，也为通过合理设计各种2D材料的光学性能优化开辟了新的途径。
Layered 2D transition metal dichalcogenides (TMDCs) exhibited fascinating nonlinear optical (NLO) properties for constructing varied promising optoelectronics. However, exploring the desired 2D materials with both superior nonlinear absorption and ultrafast response in broadband spectra remain the key challenges to harvest their greatest potential. Here, based on synthesizing 2D PdSe2 films with the controlled layer number, the authors systematically demonstrated the broadband giant NLO performance and ultrafast excited carrier dynamics of this emerging material under femtosecond visible-to-near-infrared laser-pulse excitation (400-1550 nm). Layer-dependent and wavelength-dependent evolution of optical bandgap, nonlinear absorption, and photocarrier dynamics in the obtained 2D PdSe2 are clearly revealed. Specially, the transition from semiconducting to semimetallic PdSe2 induced dramatic changes of their interband absorption-relaxation process. This work makes 2D PdSe2 more competitive for future ultrafast photonics and also opens up a new avenue for the optical performance optimization of various 2D materials by rational design of these materials.