Nonlinear optical characteristics of monolayer MoSe2
Nonlinear optical characteristics of monolayer MoSe2
复制标题
DOI：
10.1002/andp.201600006
复制
发表时间：
2016-08-01
影响因子：
2.4
通讯作者：
Kim, Yong Soo
中科院分区：
文献类型：
--
作者：
Le, Chinh Tam;Clark, Daniel J.;Kim, Yong Soo
在这项研究中，我们利用来自Nd：YAG激光器的皮秒脉冲来研究单层MoSe_2的非线性光学特性。采用脉冲激光沉积MoO_3薄膜的两步法生长，在SiO_2/Si衬底上制备了MoSe_2单分子膜。拉曼散射、光致发光(PL)光谱和原子力显微镜证实了单分子膜的高光学质量。(2)在单层光学带隙附近的倍频波长为810 nm处，二阶极化率与50PmV~(-1)相近。有趣的是，与室温下的光致发光方法相比，我们的波长相关二次谐波扫描可以更有效地识别包括负电荷激子在内的束缚激子态。此外，在皮秒脉冲激励下，MoSe_2单层显示出类似于16GW cm(-2)的强激光损伤阈值。我们的发现表明，单层MoSe_2可以被认为是一种很有前途的高功率薄膜非线性光学器件和应用的候选者。
In this study, we utilized picosecond pulses from an Nd:YAG laser to investigate the nonlinear optical characteristics of monolayer MoSe2. Two-step growth involving the selenization of pulsed-laser-deposited MoO3 film was employed to yield the MoSe2 monolayer on a SiO2/Si substrate. Raman scattering, photoluminescence (PL) spectroscopy, and atomic force microscopy verified the high optical quality of the monolayer. The second-order susceptibility.(2) was calculated to be similar to 50 pm V-1 at the second harmonic wavelength lambda(SHG)similar to 810 nm, which is near the optical gap of the monolayer. Interestingly, our wavelength-dependent second harmonic scan can identify the bound excitonic states including negatively charged excitons much more efficiently, compared with the PL method at room temperature. Additionally, the MoSe2 monolayer exhibits a strong laser-induced damage threshold similar to 16 GW cm(-2) under picosecond-pulse excitation. Our findings suggest that monolayer MoSe2 can be considered as a promising candidate for high-power, thin-film-based nonlinear optical devices and applications.