Ferroelectric Domain Control of Nonlinear Light Polarization in MoS₂ via PbZr_0.2Ti_0.8O₃ Thin Films and Free‐Standing Membranes

Abstract

Two‐dimensional (2D) transition metal dichalcogenides (TMDCs) such as MoS2 exhibit exceptionally strong nonlinear optical responses, while nanoscale control of the amplitude, polar orientation, and phase of the nonlinear light in TMDCs remains challenging. In this work, by interfacing monolayer MoS2 with epitaxial PbZr0.2Ti0.8O3 (PZT) thin films and free‐standing PZT membranes, the amplitude and polarization of the second harmonic generation (SHG) signal are modulated via ferroelectric domain patterning, which demonstrates that PZT membranes can lead to in‐operando programming of nonlinear light polarization. The interfacial coupling of the MoS2 polar axis with either the out‐of‐plane polar domains of PZT or the in‐plane polarization of domain walls tailors the SHG light polarization into different patterns with distinct symmetries, which are modeled via nonlinear electromagnetic theory. This study provides a new material platform that enables reconfigurable design of light polarization at the nanoscale, paving the path for developing novel optical information processing, smart light modulators, and integrated photonic circuits.

Ferroelectric Polarization‐Mediated Modulation of Optical Properties in 2D van der Waals Architectures

“…The integration of ferroelectric insulators and 2D semiconductors to form ferroelectric field-effect transistors [11] and negative capacitance field-effect transistors, [12] has been proposed and investigated to combine the advantages of both ferroelectrics and 2D semiconductors. Recent developments in modulating the light emission in 2D TMDs have included the use of LiNbO 3 , [13] Pb(Zr 1-x Ti x )O 3 , [14,15] and P(VDF-TrFE), [11] all of which are based on bulk-state ferroelectrics. In contrast to traditional 3D crystals, different kinds of 2D materials can be arbitrarily combined with vdWs forces, much like Lego bricks, to create heterojunctions, which are not constrained by lattice mismatches and exhibit higher degrees of freedom.…”

“…Similar research concepts were previously used to construct optoelectronic devices with ferroelectric materials serving as gate electrodes. [11][12][13][14][15] Due to the benefits of lowdimensional materials and ferroelectric materials complementing each other based on the highly polarized electric field in ferroelectric materials and the nanoscale of low-dimensional materials, novel optoelectronic devices can be realized. Wang et al employed P(VDF-TrFE), for instance, to control the optoelectronic performance of MoS 2 .…”

Optical Modulation of MoTe2/Ferroelectric Heterostructure via Interface Doping

“…Ferroelectric materials possess switchable spontaneous polarizations below a critical temperature. An electric field is the most common method to switch polarization, while other external stimuli, such as stress field, − chemical doping, , and light, − also have been reported to modulate ferroelectric polarization. Among those methods, optical modulation is one of the most convenient and flexible ways to interact with the polarization order.…”

Electrode Effect on Ferroelectricity in Free-Standing Membranes of PbZr0.2Ti0.8O3

“…The flexible nature also facilities strain engineering via stretchable or corrugated base layers, which leads to substantial modulation of their bandgap, coercive field ( E c ), , dielectric permittivity, ferroelastic domains, and photovoltaic response . Unlike epitaxial complex oxide heterostructures, whose preparation imposes stringent requirements for the structural similarity between the constituent layers, ferroelectric oxide membranes can be easily integrated with the mainstream Si platform ,, and two-dimensional (2D) van der Waals materials , for developing flexible nanoelectronics, optics, and energy applications. ,, It also possesses distinct advantages compared with ferroelectric polymers and 2D van der Waals ferroelectrics for its high Curie temperature ( T C ), large polarization ( P ), and scalable synthesis. A wide range of device concepts have been realized based on ferroelectric oxide membranes, including ferroelectric tunnel junctions, ,, ferroelectric field effect transistors (FETs), reconfigurable optical filters, DW memories, and supercapacitors …”

“…3,20,21 It also possesses distinct advantages compared with ferroelectric polymers 22 and 2D van der Waals ferroelectrics 23 for its high Curie temperature (T C ), large polarization (P), and scalable synthesis. A wide range of device concepts have been realized based on ferroelectric oxide membranes, including ferroelectric tunnel junctions, 16,17,24 ferroelectric field effect transistors (FETs), 19 reconfigurable optical filters, 18 DW memories, 25 and supercapacitors. 26 This article is licensed under CC-BY-NC-ND 4 For perovskite oxides, the type of electrode has a significant impact on T C , polarization dynamics, domain formation, and size scaling because the ferroelectric instability depends sensitively on the depolarization field, 27,28 strain, 29 and defect states.…”