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1.
Phys Chem Chem Phys ; 22(6): 3691-3701, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32003366

RESUMO

Herein, we firstly present the (K,Bi)(Nb,Yb)O3 inorganic ferroelectric photovoltaic (FPV) film, in which a nearly ideal bandgap of ∼1.45 eV in the center of the solar spectrum and the co-existence of oxygen vacancies as well as ferroelectric polarization were confirmed. Furthermore, a novel cell structure is successfully fabricated by combining charge-transporting TiO2 nanoparticles, the perovskite sensitizer and a light-absorbing oxide hole p-type NiO conductor to realize a 1 V open circuit voltage, which can be increased to 1.56 V by adjusting the test bias near the coercive voltage. Additionally, under simulated standard AM 1.5G illumination, a fill factor of 86% and a power conversion efficiency of 0.85% are achieved via oxygen vacancy electromigration and polarization switching modulation. It is shown that the obtained power conversion efficiency is one to three orders of magnitude higher than those of pure BiFeO3 and Pb(Zr,Ti)O3. The enhanced PV effects are well elucidated using the transformation from a Schottky-like barrier to Ohmic contacts caused by polarization switching and oxygen vacancies. Building upon the above studies, deep insights into the bandgap tunability and PV effects in ferroelectric films with high oxygen vacancy concentration are provided and will facilitate a new versatile route for exploring high PV performance based on inorganic ferroelectric films.

2.
Nat Commun ; 11(1): 101, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900395

RESUMO

Sensitive photodetection is crucial for modern optoelectronic technology. Two-dimensional molybdenum disulfide (MoS2) with unique crystal structure, and extraordinary electrical and optical properties is a promising candidate for ultrasensitive photodetection. Previously reported methods to improve the performance of MoS2 photodetectors have focused on complex hybrid systems in which leakage paths and dark currents inevitably increase, thereby reducing the photodetectivity. Here, we report an ultrasensitive negative capacitance (NC) MoS2 phototransistor with a layer of ferroelectric hafnium zirconium oxide film in the gate dielectric stack. The prototype photodetectors demonstrate a hysteresis-free ultra-steep subthreshold slope of 17.64 mV/dec and ultrahigh photodetectivity of 4.75 × 1014 cm Hz1/2 W-1 at room temperature. The enhanced performance benefits from the combined action of the strong photogating effect induced by ferroelectric local electrostatic field and the voltage amplification based on ferroelectric NC effect. These results address the key challenges for MoS2 photodetectors and offer inspiration for the development of other optoelectronic devices.

3.
Nanotechnology ; 31(15): 155703, 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-31860906

RESUMO

Exploring the excitonic behavior of two-dimensional (2D) alloys is of great significance, which not only could promote the understanding of fundamental photophysics in optoelectric devices, but could also guide the functional improvement of future applications. Here, we demonstrate the controllable synthesis of monolayer Mo(S x Se1-x )2 nanosheets using a one-step chemical vapor deposition method and systematical investigation on the exciton emission characteristics based on the temperature-dependent photoluminescence spectroscopy (PL) experiments. As a result, the tunable bandgap of Mo(S x Se1-x )2 alloys between 1.52 and 1.85 eV can be achieved, which is consistent with the theoretical results calculated by the ab initio density function theory. Besides, both the exciton and trion behaviors in Mo(S x Se1-x )2 are observed from the PL spectra at T = 80 K. More intriguingly, the differences between the emission energy of exciton and trion (ΔE), known as the dissociation energy of the trion, are positively correlated to the concentrations of the sulfur (S) elements, which is also proved by the theoretical calculation. Combining the experimental and theoretical results, the phenomena can be explained by the reduced dielectric screening effect and the increasing Fermi energy (E F) along with the increasing of sulfur in Mo(S x Se1-x )2 nanosheets, jointly leading to the increase of ΔE. Furthermore, the evolutions of ΔE in Mo(S x Se1-x )2 alloys as a function of temperature have been also discovered, which lay the foundation for the potential uses of 2D alloys in optoelectronic devices.

4.
J Phys Condens Matter ; 32(5): 055703, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31610532

RESUMO

Two dimensional (2D) ferroelectric materials are gaining growing attention due to their nontrival ferroelectricity, and the 2D ferroelectric heterostructures with tunable electronic, optoelectronic, or even magnetic properties, show many novel properties that do not exist in their constituents. In this work, by using the first-principles calculations, we investigate the ferroelectric and dipole control of electronic structures of the 2D ferroelectric heterostructure InTe/In2Se3. It is found that band alignment is closely dependent on the ferroelectric polarization of In2Se3. By switching the polarization of In2Se3, the band alignment of InTe/In2Se3 switches from a staggered (type II) to a straddling type (type I), and the band gap changes from indirect gap 0.76 eV to direct gap 0.15 eV. When the ferroelectric field of In2Se3 is reversed, the band alignment of InTe/In2Se3 switches from type-I to type-II, and the band gap changes from indirect gap 0.76 eV to direct gap 0.15 eV. In addition, we find that the interlayer dipole can also effectively modulate the band structure and induce the type-I to type-II band alignment transition. Our present results indicate that the 2D ferroelectric heterostructure with the tunable band alignment and band gap can be of great significance in the optoelectronic devices.

5.
Talanta ; 206: 120212, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514841

RESUMO

Graphene oxide-Fe3O4 (GO-Fe3O4) nanocomposite was synthesized by a facile chemical co-precipitation method. The GO-Fe3O4 was used as magnetic sorbent to extract the eight psychoactive drugs from urine samples. The analytes are morphine (MOR), 6-monoacetylmorphine (6-MAM), amphetamine (AMP), methamphetamine (MAMP), codeine, cocaine, dolantin and benzoylecgonine (BZE), which were determined by ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). This method has high selectivity for the target analytes. The limit of detection (LOD) and limit of quantification (LOQ) were 0.02-0.2 µg L-1 and 0.05-0.5 µg L-1, respectively. The Mandel's fitting test revealed good linearity within all linear ranges. The linear ranges were calculated as 0.05-1000 µg L-1 for AMP, MAMP, cocaine and dolantin; 0.1-1000 µg L-1 for 6-MAM and codein; and 0.5-1000 µg L-1 for MOR and BZE. The recoveries ranged in 80.4-105.5%. The intra-day and inter-day RSDs are in the range of 2.7-13.1% and 3.9-13.7%, respectively. Magnetic solid phase extraction (MSPE) with GO-Fe3O4 provides a convenient, rapid and green sample pretreatment method for extracting the target psychoactive drugs from urine. This methodology can be used for simultaneous or individual detection of eight major psychoactive drugs with high sensitivity. This method has high potential in clinical and forensic areas for psychoactive drugs analysis.


Assuntos
Grafite/química , Nanopartículas de Magnetita/química , Nanocompostos/química , Psicotrópicos/urina , Cromatografia Líquida de Alta Pressão/métodos , Óxido Ferroso-Férrico/síntese química , Grafite/síntese química , Limite de Detecção , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos
6.
J Phys Chem Lett ; 10(24): 7929-7936, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31808347

RESUMO

By comparing optical spectral results of both Sn-rich and Sn-poor Cu2ZnSnS4 (CZTS) with the previously calculated defect levels, we confirm that the band-tail states in CZTS originate from the high concentration of 2CuZn + SnZn defect clusters, whereas the deep-donor states originate from the high concentration of SnZn. In Sn-rich CZTS, the absorption, reflectance, and photocurrent (PC) spectra show band-tail states that shrink the bandgap to only ∼1.34 eV, while photoluminescence (PL) and PC spectra consistently show that abundant CuZn + SnZn donor states produce a PL peak at ∼1.17 eV and abundant SnZn deep-donor states produce a PL peak near 0.85 eV. In contrast, Sn-poor CZTS shows neither bandgap shrinking nor any deep-donor-defect induced PL and PC signals. These results highlight that a Sn-poor composition is critical for the reduction of band-tailing effects and deep-donor defects and thus the overcoming of the severe open-circuit voltage (Voc) deficiency problem in CZTS solar cells.

7.
Small ; 15(46): e1904116, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31588680

RESUMO

2D layers of metal dichalcogenides are of considerable interest for high-performance electronic devices for their unique electronic properties and atomically thin geometry. 2D SnS2 nanosheets with a bandgap of ≈2.6 eV have been attracting intensive attention as one potential candidate for modern electrocatalysis, electronic, and/or optoelectronic fields. However, the controllable growth of large-size and high-quality SnS2 atomic layers still remains a challenge. Herein, a salt-assisted chemical vapor deposition method is provided to synthesize atomic-layer SnS2 with a large crystal size up to 410 µm and good uniformity. Particularly, the as-fabricated SnS2 nanosheet-based field-effect transistors (FETs) show high mobility (2.58 cm2 V-1 s-1 ) and high on/off ratio (≈108 ), which is superior to other reported SnS2 -based FETs. Additionally, the effects of temperature on the electrical properties are systematically investigated. It is shown that the scattering mechanism transforms from charged impurities scattering to electron-phonon scattering with the temperature. Moreover, SnS2 can serve as an ideal material for energy storage and catalyst support. The high performance together with controllable growth of SnS2 endow it with great potential for future applications in electrocatalysis, electronics, and optoelectronics.

8.
ACS Appl Mater Interfaces ; 11(42): 38895-38901, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31556289

RESUMO

A Schottky barrier is a double-edged sword in electronic and optoelectronic devices, especially devices based on two-dimensional materials. It may restrict the carrier transport in devices, but it can also realize multifunctional devices by architecture design. We designed a simple but novel device structure based on theWSe2-Cr Schottky junction with an asymmetric Schottky contact area of the source and drain. A significant rectification ratio over 105 and multiple rectifying states (e.g., full pass, forward pass, off, and backward pass) were achieved in the single Schottky junction tuned by gate voltage. Furthermore, switching characteristic, rectification characteristic, and amplitude of a sin wave can be effectively modulated by the electrical field or light illumination in a signal process circuit based on the WSe2-Cr Schottky junction. The highly tunable Schottky junction working as a multimode signal processor unit has great potential in future optoelectronic-integrated chips.

9.
Small ; 15(46): e1903106, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31550085

RESUMO

Many van der Waals layered 2D materials, such as h-BN, transition metal dichalcogenides (TMDs), and group-III monochalcogenides, have been predicted to possess piezoelectric and mechanically flexible natures, which greatly motivates potential applications in piezotronic devices and nanogenerators. However, only intrinsic in-plane piezoelectricity exists in these 2D materials and the piezoelectric effect is confined in odd-layers of TMDs. The present work is intent on combining the free-standing design and piezoresponse force microscopy techniques to obtain and directly quantify the effective out-of-plane electromechanical coupling induced by strain gradient on atomically thin MoS2 and InSe flakes. Conspicuous piezoresponse and the measured piezoelectric coefficient with respect to the number of layers or thickness are systematically illustrated for both MoS2 and InSe flakes. Note that the promising effective piezoelectric coefficient (deff 33 ) of about 21.9 pm V-1 is observed on few-layered InSe. The out-of-plane piezoresponse arises from the net dipole moment along the normal direction of the curvature membrane induced by strain gradient. This work not only provides a feasible and flexible method to acquire and quantify the out-of-plane electromechanical coupling on van der Waals layered materials, but also paves the way to understand and tune the flexoelectric effect of 2D systems.

10.
Nanotechnology ; 30(42): 425404, 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31386632

RESUMO

Transition metal oxides (TMOs) as anode materials have potential for lithium-ion batteries (LIBs). However, the poor rate capacity and cycle stability restrict its application. Herein, we demonstrate a facile one-step hydrothermal method to construct a three-dimensional porous conductive network structure, which consists of thin-layered graphene, ultrafine Co3O4-CoO nanoparticles and nitrogen-doped carbon. This unique structure can effectively prevent particle agglomeration and cracking caused by volume expansion, provide fast passage for lithium ion/electron transport during cycling and improve the electrical conductivity of the electrode. Moreover, the electrochemical kinetic analysis proves that this is a process dominated by pseudocapacitive behavior. Consequently, the N-C@Co3O4-CoO@GO hybrid electrode delivers an ultrahigh capacity of 1 273.1 mA h g-1 at 0.1 A g-1 and superior rate performance (725.1 mA h g-1 at 5 A g-1). Additionally, it exhibits a high reversible cycling capacity of 787.4 mA h g-1 at 1 A g-1 over 600 cycles and even maintains excellent cycling stability for a ultra-long cycles at 5 A g-1. This work provides a feasible strategy for fabricating the N-C@Co3O4-CoO@GO composite as a promising high-performance TMOs anode for LIBs.

11.
Adv Sci (Weinh) ; 6(15): 1901050, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31406679

RESUMO

Broadening the spectral range of photodetectors is an essential topic in photonics. Traditional photodetectors are widely used; however, the realization of ultrabroad spectrum photodetectors remains a challenge. Here, a photodetector constructed by a hybrid quasi-freestanding structure of organic ferroelectric poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) with molybdenum disulfide (MoS2) is demonstrated. The 2D MoS2 with the ultrathin structure brings a great benefit of heat dissipation for the pyroelectric infrared detector. By coupling the mechanisms of pyroelectrics, photoconductor, and phototransistor effect, an ultrabroad spectrum response ranging from ultraviolet (375 nm) to long-wavelength infrared (10 µm) is achieved. In the 2.76-10 µm spectral range, the 2D MoS2 is used to read and amplify the photocurrent induced by the pyroelectric effect of P(VDF-TrFE). The sensitivity of the device in this spectral range is greatly enhanced. A high responsivity of 140 mA W-1, an on/off photocurrent switching ratio up to 103, and a quick response of 5.5 ms are achieved. Moreover, the ferroelectric polarization field dramatically enhances the photoconductive properties of MoS2 and restrains dark current and noise. This approach constitutes a reliable route toward realizing high-performance photodetectors with a remarkable ultrabroad spectrum response, high responsivity, low power consumption, and room-temperature operation.

12.
Nanotechnology ; 30(46): 464001, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31422955

RESUMO

Memristors have been intensively studied in recent years as promising building blocks for next-generation nonvolatile memory, artificial neural networks and brain-inspired computing systems. However, most memristors cannot simultaneously function in extremely low and high temperatures, limiting their use for many harsh environment applications. Here, we demonstrate that the memristors based on high-Curie temperature ferroelectrics can resolve these issues. Excellent synaptic learning and memory functions can be achieved in BiFeO3 (BFO)-based ferroelectric memristors in an ultra-wide temperature range. Correlation between electronic transport and ferroelectric properties is established by the coincidence of resistance and ferroelectricity switch and the direct visualization of local current and domain distributions. The interfacial barrier modification by the reversal of ferroelectric polarization leads to a robust resistance switching behavior. Various synaptic functions including long-term potentiation/depression, consecutive potentiation/depression and spike-timing dependent plasticity have been realized in the BFO ferroelectric memristors over an extremely wide temperature range of -170 °C âˆ¼ 300 °C, which even can be extended to 500 °C due to the robust ferroelectricity of BFO at high temperatures. Our findings illustrate that the BFO ferroelectric memristors are promising candidates for ultra-wide temperature electronic synapse in extreme or harsh environments.

13.
Sci Rep ; 9(1): 12309, 2019 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-31444384

RESUMO

InN superconductivity is very special among III-V semiconductors, as other III-V semiconductors (such as GaAs, GaN, InP, InAs, etc.) usually lack strong covalent bonding and thus seldom show superconductivity at low temperatures. Here, we probe the different superconducting phase transitions in InN highlighted by its microstructure. Those chemical-unstable phase-separated inclusions, such as metallic indium or In2O3, are intentionally removed by HCl acid etching. The quasi-two-dimensional vortex liquid-glass transition is observed in the sample with a large InN grain size. In contrast, the superconducting properties of InN with a small grain size are sensitive to acid etching, showing a transition into a nonzero resistance state when the temperature approaches zero. Since the value of ξ0 (the zero-temperature-limit superconducting coherence length) is close to the grain size, it is suggested that individual InN grains and intergrain coupling should be responsible for the sample-dependent InN superconducting phase transition. Our work establishes a guideline for engineering superconductivity in III-nitride.

14.
Nanoscale ; 11(22): 10636-10645, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31065661

RESUMO

Hybrid organic-inorganic metal halide perovskites are currently arousing enthusiasm and stimulating huge activity across several fields of optoelectronics due to their outstanding properties. In this study, we present the incoherent random lasing (RL) emissions from CH3NH3PbBr3 perovskite thin films on both planar fluorine-doped tin oxide (FTO) substrates and patterned sapphire substrates (PSSs). A detailed examination of the spectral evolution indicates that inelastic exciton-exciton scattering called P-emission is the most plausible mechanism accounting for the lasing emissions. The RL threshold of the perovskite films on PSSs is found to be effectively reduced by more than one order of magnitude from 2.55 to 0.15 µJ per pulse compared to that on FTO substrates. The giant threshold reduction is ascribed to the enhanced random scattering of light and the photon recycling induced by the multireflection processes at the perovskite/PSS interface, which increases the likelihood that the inoperative random rays will re-enter the possible optical loops formed among the perovskite particles, resulting in considerable optical resonance enhancement. The simulation results reveal that the light extraction efficiency on the top facet of the perovskites is significantly increased by approximately 155% by utilizing the PSS instead of the FTO substrate. Moreover, the first direct experimental observation of the multireflection phenomenon of light, as well as the dynamic processes of photon propagation in the composite PSS structure, is presented by Kerr-gate-based time-resolved photoluminescence. Our results provide an effective strategy to achieve high-performance perovskite random lasers and novel light-emitting devices for speckle-free full-field imaging and solid-state lighting applications, by introducing ingeniously designed periodic nano-/microscale optical structures.

15.
ACS Appl Mater Interfaces ; 11(26): 23667-23672, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31144499

RESUMO

Recently, two-dimensional (2D) materials, especially transition-metal dichalcogenides (TMDCs), have attracted extensive interest owing to their potential applications in optoelectronics. Here, we demonstrate a hybrid 2D-zero-dimensional (0D) photodetector, which consists of a single-layer or few-layer molybdenum disulfide (MoS2) thin film and a thin layer of core/shell zinc cadmium selenide/zinc sulfide (ZnCdSe/ZnS) colloidal quantum dots (QDs). It is worth mentioning that the photoresponsivity of the hybrid 2D-0D photodetector is 3 orders of magnitude larger than the TMDC photodetector (from 10 to 104 A W-1). The detectivity of the hybrid structure detector is up to 1012 Jones, and the gain is up to 105. Due to an effective energy transfer from the photoexcited QD sensitizing layer to MoS2 films, light absorption is enhanced and more excitons are generated. Thus, this hybrid 2D-0D photodetector takes advantage of high charge mobility in the MoS2 layer and efficient photon absorption/exciton generation in the QDs, which suggests their promising applications in the development of TMDC-based optoelectronic devices.

16.
Small ; 15(17): e1900236, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30932339

RESUMO

Van der Waals epitaxy (vdWE) is crucial for heteroepitaxy of covalence-bonded semiconductors on 2D layered materials because it is not subject to strict substrate requirements and the epitaxial materials can be transferred onto various substrates. However, planar film growth in covalence-bonded semiconductors remains a critical challenge of vdWE because of the extremely low surface energy of 2D materials. In this study, direct growth of wafer-scale single-crystalline cadmium telluride (CdTe) films is achieved on 2D layered transparent mica through molecular beam epitaxy. The vdWE CdTe films exhibit a flat surface resulting from the 2D growth regime, and high crystal quality as evidenced by a low full width at half maximum of 0.05° for 120 nm thick films. A perfect lattice fringe appears at the interfaces, implying a fully relaxed state of the epitaxial CdTe films correlated closely to the unique nature of vdWE. Moreover, the vdWE CdTe photodetectors demonstrate not only ultrasensitive optoelectronic response with optimal responsivity of 834 A W-1 and ultrahigh detectivity of 2.4 × 1014 Jones but also excellent mechanical flexibility and durability, indicating great potential in flexible and wearable devices.

17.
Sensors (Basel) ; 19(5)2019 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-30871069

RESUMO

Wearable electronic sensing devices are deemed to be a crucial technology of smart personal electronics. Strain and pressure sensors, one of the most popular research directions in recent years, are the key components of smart and flexible electronics. Graphene, as an advanced nanomaterial, exerts pre-eminent characteristics including high electrical conductivity, excellent mechanical properties, and flexibility. The above advantages of graphene provide great potential for applications in mechatronics, robotics, automation, human-machine interaction, etc.: graphene with diverse structures and leverages, strain and pressure sensors with new functionalities. Herein, the recent progress in graphene-based strain and pressure sensors is presented. The sensing materials are classified into four structures including 0D fullerene, 1D fiber, 2D film, and 3D porous structures. Different structures of graphene-based strain and pressure sensors provide various properties and multifunctions in crucial parameters such as sensitivity, linearity, and hysteresis. The recent and potential applications for graphene-based sensors are also discussed, especially in the field of human motion detection. Finally, the perspectives of graphene-based strain and pressure sensors used in human motion detection combined with artificial intelligence are surveyed. Challenges such as the biocompatibility, integration, and additivity of the sensors are discussed as well.


Assuntos
Inteligência Artificial , Grafite/química , Nanoestruturas/química
18.
Nanoscale ; 11(18): 8744-8751, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-30806411

RESUMO

Memristors have been extensively studied for synaptic simulation and neuromorphic computation. Instead of focusing on implementing specific synaptic learning rules by carefully engineering external programming parameters, researchers recently have paid more attention to taking advantage of the second-order memristor that is more analogous to biologic synapses and modulated not only by external inputs but also by internal mechanisms. However, experimental evidence is still scarce. Here, we explore a BiMnO3 memristor by applying simple spike forms. The filament evolution dynamics, including processes of forming and spontaneous decay, were directly observed by the conductive atomic force microscopy (c-AFM) technique. We propose that the unique conductance state of the BMO memristor is regulated by the oxygen vacancy (VO) dynamic process. We believe this primary result is helpful to improve understanding of the internal mechanisms of the second-order oxide memristor, which exhibits promising application in building selectors, memories and neuromorphic-computing systems.

19.
J Phys Condens Matter ; 31(20): 205501, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-30708355

RESUMO

The ferromagnetism of the two dimensional (2D) Cr2Ge2Te6 atomic layers with the perpendicular magnetic anisotropy and the Curie temperature 30-50 K has recently been experimentally confirmed. By performing the density-functional theory calculations, we demonstrate that the magnetic properties of bilayer Cr2Ge2Te6 can be flexibly tailored, due to the effective band structure tuning by the external electric field. The electric field induces the semiconductor-metal transition and redistributes charge and spin between the two layers. Furthermore, the magnetic anisotropy energy of the bilayer Cr2Ge2Te6 can be obviously enhanced by the electric field, which is helpful to stabilize the long-range ferromagnetic order. Our study about the electric manipulation of magnetism based on the band structure engineering generally exists in 2D magnetic systems and will be of great significance in low-dimensional all-electric spintronics.

20.
Nanotechnology ; 30(23): 235701, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-30780144

RESUMO

For assisting the in-depth investigations of widespread electromechanical phenomena in functional materials, piezoresponse force microscopy (PFM) has gradually evolved to realize full information-flow acquisition and fit the conductive liquid working environments. Here, we designed data cube (DCUBE) based PFM to collect the electromechanical effect into a high-dimensional array of piezoresponse by adding ac bias with a wide range of frequencies to the probe. The electromechanical and mechanical spectra can be consecutively extracted at each pixel in the intermittent-contact mode. High-resolution ferroelectric domains of the poled LiNbO3 were mapped, corresponding to the ideal phase contrasts of about 180° in air, decane, and deionized water. Rich information detection and non-contact mode in DCUBE-PFM bring many merits on the electromechanical characterizations, especially for elastic-inhomogeneous surfaces and soft materials. Moreover, we systematically reveal the Debye screening effect and time-resolved field-oriented ion dynamics, which play crucial roles in the reduction of PFM spatial resolution in electrolytes. These physical discussions provide strategies to further realize high-resolution electromechanical imaging in highly conductive liquid environments.

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