Niobium Carbide MXenes with Broad-Band Nonlinear Optical Response and Ultrafast Carrier Dynamics
Niobium Carbide MXenes with Broad-Band Nonlinear Optical Response and Ultrafast Carrier Dynamics
复制标题
具有宽带非线性光学响应和超快载流子动力学的碳化铌 MXene
DOI：
10.1021/acsnano.0c04390
复制
发表时间：
2020
期刊：
影响因子：
17.1
通讯作者：
Si Xiao
中科院分区：
文献类型：
--
作者：
Yingwei Wang;Yingwei Wang;Keqiang Chen;Kun Qi;Tianyu Xue;Han Zhang;Jun He;Si Xiao
探索新兴的有前途的二维（2D）材料（如MXenes）的非线性光子学将促进宽带光电和光子应用的发展。本文系统地研究了一种新兴的MXene（Nb 2C）在可见光到近红外波段的宽带非线性光学响应和受激载流子动力学。所获得的非线性光学响应显示波长和激发强度的依赖性。三阶非线性光学系数Imχ（3）的虚部为-1.4 × 10 ~（-10）esu，品质因数为7.5 × 10 ~（-12）esucm。有趣的非线性吸收响应反演特性（例如，从可饱和吸收到双光子吸收的转变），在非线性光子学中，例如光开关，有可能有重要的应用。我们还表明，依赖于波长的弛豫时间由两个不同的弛豫分量，即，时间常数，其中一个是几百飞秒，另一个是几皮秒。我们的研究结果表明，2D Nb 2C在近红外纳米光子应用中具有很大的潜力，并为基于2D材料的纳米光子器件及其他器件提供了一个很有前途的候选者。
Exploring the nonlinear photonics of emerging promising two-dimensional (2D) materials like MXenes will boost the development of broad-band optoelectronic and photonic applications. In this paper, the broad-band nonlinear optical response and the excited-carrier dynamics of an emerging MXene, Nb2C, are systematically investigated for the wavelength range of visible to the near-infrared band. The obtained nonlinear optical response shows a wavelength and excitation intensity dependence. The imaginary part of the third-order nonlinear optical susceptibility Imχ(3) and figure of merit were found to be -1.4 × 10-10 esu and 7.5 × 10-12 esu cm, respectively. The interesting nonlinear absorption response inversion properties (e.g., a shift from saturable absorption to two-photon absorption) of Nb2C nanosheets in the near-infrared promise possible important applications in nonlinear photonics, such as an optical switch. We also demonstrate that the wavelength-dependent relaxation times consist of two different relaxation components, that is, time constants in which one is hundreds of femtoseconds and the other is several picoseconds. Our results indicate promising potential in near-infrared nanophotonic applications of 2D Nb2C and offer a promising candidate for 2D-material-based nanophotonic devices and beyond.