当前位置:
X-MOL 学术
›
Nano Lett.
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Electric-Field Switchable Second-Harmonic Generation in Bilayer MoS2 by Inversion Symmetry Breaking
Nano Letters ( IF 9.6 ) Pub Date : 2016-12-19 00:00:00 , DOI: 10.1021/acs.nanolett.6b04344 J. Klein 1 , J. Wierzbowski 1 , A. Steinhoff 2 , M. Florian 2 , M. Rösner 2, 3 , F. Heimbach 4 , K. Müller 1 , F. Jahnke 2 , T. O. Wehling 2, 3 , J. J. Finley 1 , M. Kaniber 1
Nano Letters ( IF 9.6 ) Pub Date : 2016-12-19 00:00:00 , DOI: 10.1021/acs.nanolett.6b04344 J. Klein 1 , J. Wierzbowski 1 , A. Steinhoff 2 , M. Florian 2 , M. Rösner 2, 3 , F. Heimbach 4 , K. Müller 1 , F. Jahnke 2 , T. O. Wehling 2, 3 , J. J. Finley 1 , M. Kaniber 1
Affiliation
We demonstrate pronounced electric-field-induced second-harmonic generation in naturally inversion symmetric 2H stacked bilayer MoS2 embedded into microcapacitor devices. By applying strong external electric field perturbations (|F| = ±2.6 MV cm–1) perpendicular to the basal plane of the crystal, we control the inversion symmetry breaking and, hereby, tune the nonlinear conversion efficiency. Strong tunability of the nonlinear response is observed throughout the energy range (Eω ∼ 1.25–1.47 eV) probed by measuring the second-harmonic response at E2ω, spectrally detuned from both the A- and B-exciton resonances. A 60-fold enhancement of the second-order nonlinear signal is obtained for emission at E2ω = 2.49 eV, energetically detuned by ΔE = E2ω – EC = −0.26 eV from the C-resonance (EC = 2.75 eV). The pronounced spectral dependence of the electric-field-induced second-harmonic generation signal reflects the bandstructure and wave function admixture and exhibits particularly strong tunability below the C-resonance, in good agreement with density functional theory calculations. Moreover, we show that the field-induced second-harmonic generation relies on the interlayer coupling in the bilayer. Our findings strongly suggest that the strong tunability of the electric-field-induced second-harmonic generation signal in bilayer transition metal dichalcogenides may find applications in miniaturized electrically switchable nonlinear devices.
中文翻译:
通过反对称对称破坏双层MoS 2中的电场可转换二次谐波。
我们展示了嵌入微电容器器件中的自然反演对称2H堆叠双层MoS 2中明显的电场诱导的二次谐波产生。通过施加垂直于晶体基面的强外部电场扰动(| F | =±2.6 MV cm –1),我们可以控制反演对称性的破坏,从而调整非线性转换效率。非线性响应的可调谐性强在整个能量范围(观测Ë ω通过测量在二次谐波响应探测〜1.25-1.47 eV)的È 2ω,从A和B激子共振频谱失谐。在用于发射获得的第二阶非线性信号的60倍的增强Ê 2ω = 2.49电子伏特,通过Δ能量失谐Ê = ë 2ω - ë Ç = -0.26 eV的从C-共振(É Ç= 2.75 eV)。电场引起的二次谐波产生信号的明显频谱依赖性反映了能带结构和波函数混合,并在C共振以下表现出特别强的可调谐性,与密度泛函理论计算非常吻合。此外,我们表明,磁场诱导的二次谐波产生依赖于双层中的层间耦合。我们的发现强烈表明,在双层过渡金属二卤化物中,电场感应产生的二次谐波产生信号具有很强的可调谐性,可以在小型电可开关非线性器件中找到应用。
更新日期:2016-12-19
中文翻译:
通过反对称对称破坏双层MoS 2中的电场可转换二次谐波。
我们展示了嵌入微电容器器件中的自然反演对称2H堆叠双层MoS 2中明显的电场诱导的二次谐波产生。通过施加垂直于晶体基面的强外部电场扰动(| F | =±2.6 MV cm –1),我们可以控制反演对称性的破坏,从而调整非线性转换效率。非线性响应的可调谐性强在整个能量范围(观测Ë ω通过测量在二次谐波响应探测〜1.25-1.47 eV)的È 2ω,从A和B激子共振频谱失谐。在用于发射获得的第二阶非线性信号的60倍的增强Ê 2ω = 2.49电子伏特,通过Δ能量失谐Ê = ë 2ω - ë Ç = -0.26 eV的从C-共振(É Ç= 2.75 eV)。电场引起的二次谐波产生信号的明显频谱依赖性反映了能带结构和波函数混合,并在C共振以下表现出特别强的可调谐性,与密度泛函理论计算非常吻合。此外,我们表明,磁场诱导的二次谐波产生依赖于双层中的层间耦合。我们的发现强烈表明,在双层过渡金属二卤化物中,电场感应产生的二次谐波产生信号具有很强的可调谐性,可以在小型电可开关非线性器件中找到应用。