Well-aligned Arrays Research Articles

In Situ Growth of Well-Aligned MOF Nanoneedle Arrays into Composite Photothermal Membranes for Solar Desalination.

The solar-driven interfacial evaporation (SDIE) technology serves as a clean and facile approach combining seawater desalination to address water shortage and energy crisis. Recently, porous organic framework materials have aroused great attention, and the development of MOF-based composites with significant performance in photothermal conversion and water activation has become one of the important focuses in this field. In this work, an MOF-based composite photothermal membrane (PON@MOF) was prepared via the in situ growth of metal-organic framework (MOF) nanoneedle arrays induced by a pyridine-based organic polymer nanowire network (PON). The PON@MOF membrane possessed an MOF array layer, a PON-induced layer, and a porous support layer. The PON is rich in coordinated nitrogen atoms for anchoring the metal-ion source, and the main role of the PON layer is to provide favorable nucleation sites and orient in situ growth of well-aligned MOF nanoneedle arrays. With the highly conjugated framework of PON@MOF and the light trapping of the nanoarrays strengthening the photothermal conversion as well as the hydrophilic chemical structure facilitating the decrease of the water evaporation enthalpy, the PON@MOF membrane realizes highly efficient thermal vapor conversion. Under solar irradiation (1.0 kW m-2), PON@MOF demonstrated an evaporation rate of 2.14 kg m-2 h-1 and a solar-to-vapor conversion efficiency of 98.5%. Meanwhile, the PON@MOF membrane has excellent salt resistance and stability, highlighting its potential application in desalination. Overall, this work provides a special idea for the structural design of photothermal composites for solar desalination and freshwater production.

Epitaxial growth of bottom-crosslinked ZnGa2O4 nanowire arrays on c-plane GaN/Al2O3 substrate

The epitaxial growth of highly ordered ZnGa2O4 nanowire arrays and the construction of connectivity states between the individually segregated nanowires would significantly improve the performance of ZnGa2O4-based devices and expand their application fields. Herein, a strategy to construct high crystalline quality and well-aligned bottom-crosslinked ZnGa2O4 nanowire arrays along seven equivalent crystallographic directions of [111], [111̅], [11̅1], [1̅11], [11̅1̅], [1̅11̅] and [1̅1̅1] on Au-coated (0001) GaN/Al2O3 substrates using chemical vapor deposition (CVD) is proposed. The vapor-liquid-solid (VLS) mechanism dominates the entire growth process. The horizontal nanowires induced to nucleate and grow by catalyst droplets encountered and then turned towards inclined nanowires. Meanwhile, catalyst droplets that failed to move horizontally were enclosed by horizontal nanowires, resulting in the induction of perpendicular nanowire growth. The film-like horizontal nanowires connected all the inclined and perpendicular nanowires to form the bottom-crosslinked nanowire arrays. Additionally, the morphology, structure and optical properties of the ZnGa2O4 nanowire arrays, as well as the influence of Au layer thickness and growth time on the growth of ZnGa2O4 nanowires, were further characterized and thoroughly investigated. The proposed strategy achieved the growth of epitaxial well-aligned ZnGa2O4 nanowire arrays with bottom cross-linking, which is conducive to the application of ZnGa2O4 nanowires in optoelectronics.

Preparation and Assembly of Carbon Nanotube/Silica Core-Shell Nanowires to Realize High-Density and Well-Aligned Nanotube Arrays with Uniform and Tunable Pitch

This study introduces a novel method to fabricate high-density, well-aligned arrays of carbon nanotubes (CNTs) with tunable pitch, utilizing a core-shell nanowire structure of CNTs and silica. The approach involves a modified Stober process to achieve controlled deposition of silicon dioxide around individual CNTs, forming robust core-shell nanowires. By optimizing the Stober process, the shell size can be precisely controlled down to sub 10nm scale while maintaining the individualized nature of the CNTs. Densely packed and precisely aligned CNT arrays are created using Langmuir-Schaefer process. After assembly, the silica shell, acting as a physical spacer, can be easily removed by HF etching, exposing the CNTs while maintaining their alignment. The developed high-density, well-aligned CNT arrays with tunable pitch show significant promise for applications in nanoelectronics, sensors, and other emerging technologies. This methodology offers a robust and scalable approach for CNT array fabrication, opening avenues for tailoring array properties to meet specific application requirements.

Orientational alignment of semiconducting carbon nanotubes by the parallel steps of high-index copper foils

Numerous research efforts have focused on the deposition and morphology control of semiconducting single-walled carbon nanotubes (s-SWCNTs) to exploit their extraordinary properties to fulfill in building next-generation electronics. However, it is difficult to realize s-SWCNT arrays at the controlled densities and alignments desired for high-performance devices. Here, we developed a novel approach to control the morphology and alignment of s-SWCNTs. Random s-SWCNT networks came into being well-aligned s-SWCNT arrays (within the alignment of 16.9°) along with the recrystallization of copper foils from polycrystalline to single-crystalline. Grain boundary migration induced motion and alignment of s-SWCNTs. In this way, high-quality s-SWCNTs were assembled into well-aligned CNT arrays on single-crystal high-index copper foils. Furthermore, theoretical calculations confirm that the strong binding energy between the s-SWCNTs and the copper edge steps leads to the orientational alignment of the s-SWCNTs on the copper surface.

A 3D hierarchical TiO2/CaIn2S4/C3N4 arrays photoanode with dual-heterojunction for enhanced photoelectrochemical performance

A novel 3D hierarchical TiO2/CaIn2S4/C3N4 arrays with dual heterojunctions photoanode is constructed by stepwise deposition of CaIn2S4 nanosheets and ultrathin C3N4 onto the well-aligned TiO2 nanorods arrays. Integrating the merit of the superior ability of CaIn2S4 and C3N4 to harvest visible light, dual type-Ⅱ heterojunction band structure and one-dimensional ordered nanostructures, the TiO2/CaIn2S4/C3N4 photoanode exhibits simultaneous significant improvements in visible-light harvesting, charge separation and electron transfer capability. At 1.23 V (versus reversible hydrogen electrode) under AM 1.5 G irradiation, the TiO2/CaIn2S475/C3N4 photoanode exhibits a photocurrent density of 4.5 mA cm−2, which is 5.2 and 51.1-fold higher than that of TiO2/CaIn2S475 and pristine TiO2 photoanode, respectively. Moreover, the applied bias photo-to-current efficiency (ABPE) of the TiO2/CaIn2S475/C3N4 photoanode reaches 3.5% at 0.36 V (versus reversible hydrogen electrode). These results are helpful for fabricating more efficient heterostructure photoelectrodes.

Fabrication of well-aligned Co-MOF arrays through a controlled and moderate process for the development of a flexible tetrabromobisphenol A sensor.

Tetrabromobisphenol A (TBBPA) has attracted a great deal of attention due to its side effects and potential bioaccumulation properties. It is of great importance to construct and develop novel electrochemical sensors for the sensitive and selective detection of TBBPA. In the present study, cobalt (Co) based metal-organic frameworks (MOFs) were synthesized on carbon cloth (CC) by using cobalt nitrate hexahydrate and 2-methylimidazole. The morphological characterization was carried out by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The results showed that Co-MOFs/CC have a leaf-like structure and abundant surface functional groups. The electrochemical properties of the sensor were investigated by differential pulse voltammetry (DPV). The effects of different ratios of metal ions to organic ligands, reaction temperature, time, concentration, pH value of the electrolyte, and incubation time on the oxidation peak current of TBBPA were studied. Under the optimal conditions, the linear range of the designed sensor was 0.1 μM-100 μM, and the limit of detection was 40 nM. The proposed sensor is simple, of low cost and efficient, which can greatly facilitate the detection tasks of environmental monitoring workers.

Vertically Well-Aligned ZnO Nanoscintillator Arrays with Improved Photoluminescence and Scintillation Properties.

ZnO nanoarrays were grown via a low-temperature hydrothermal method. Solutions, each with different additive combinations, were prepared and evaluated. The effects of the additives involved in the growth procedure, i.e., ammonium hydroxide and sodium citrate, were studied in terms of the morphological, optical and scintillation properties of the ZnO nanostructures. Measurement of the nanorod (NR) length, corresponding photoluminescence (PL) and scintillation spectra and their dependence on the additives present in the solution are discussed. ZnO NRs grown on a silica substrate, whose UV transmission was found to be better than glass, showed high-quality structural and optical properties. It was found that the addition of sodium citrate significantly reduced defects and correspondingly increased the intrinsic near-band-edge (NBE) UV emission intensity at ~380 nm. To obtain high-quality nanostructures, samples were annealed in a 10% H2 + 90% N2 atmosphere. The anneal in the forming gas atmosphere enhanced the emission of the UV peak by reducing defects in the nanostructure. NRs are highly tapered towards the end of the structure. The tapering process was monitored using time growth studies, and its effect on PL and reflectance spectra are discussed. A good alpha particle response was obtained for the grown ZnO NRs, confirming its potential to be used as an alpha particle scintillator. After optimizing the reaction parameters, it was concluded that when ammonium hydroxide and sodium citrate were used, vertically well-aligned and long ZnO nanoarrays with highly improved optical and scintillation properties were obtained.

Improved Sensitivity and Selectivity of Glutathione Detection through Target-Driven Electron Donor Generation in Photoelectrochemical Electrodes.

Glutathione (GSH) plays a vital role in many physiological processes, and its abnormal levels have been found to be associated with several diseases. In contrast to traditional methods using electron donor-containing electrolytes for photoelectrochemical (PEC) sensing, in this study, a target-driven electron donor generation in a PEC electrode was developed to detect GSH. Using well-aligned TiO2 nanotube arrays (TNTs) as the PEC substrate, mesoporous MIL-125(Ti) was grown in the TNTs through an in situ solvothermal method and subsequent two-step annealing treatment. The accommodation capacity of mesoporous MIL-125(Ti) allows a well loading of cystine and Pt nanoclusters (NCs). Taking advantage of the specific cleavage ability of disulfide bonds by GSH, cystine was converted to cysteine, which served as the electron donor for the PEC process. Benefiting from the confinement effect of mesoporous MIL-125(Ti), cysteine was effectively oxidized to cysteine sulfinic acid by the photogenerated holes. Importantly, the highly active Pt NCs decorated in the mesopores not only improved the charge transfer but also accelerated the above oxidation reaction. The synergistic effect of these factors enabled the efficient separation of the photogenerated electron-hole pairs, which induced a significant photocurrent increase and in turn led to the high-sensitivity detection of GSH. Consequently, the proposed PEC biosensor exhibited excellent performance in the detection of GSH in serum specimens. The target-driven electron donor generation designed in this study might open a new route for developing sensitive and selective PEC biosensors with application in complex biological environments.

Synthesis and photoelectrochemical properties of tungsten oxide arrays with a snowflake-like hierarchical structure

In this study, we successfully fabricated well-aligned WO3 snowflake-like hierarchical arrays (SHAs) with (020) facet perpendicular to FTO substrate. The fabricated samples were characterized by XRD, SEM, and UV–vis. The SHA photoanode exhibited an impressive photocurrent density of 2.43 mA·cm−2 at 1.23 V vs RHE, which is 1.76 times higher than the sandwich-like structures (SSs). This improved performance can be attributed to the special SHAs and the preferred orientation, which would effectively promote the separation and transfer of carriers.

Face-Dependent Reconstruction of Bi-Oxyiodides toward Selective Growth of (BiO)2 CO3 Edge Side to Maximize CO2 Conversion Efficiency.

Chemical reconstruction of bismuth oxyiodides using bicarbonates is tried to selectively grow (BiO)2 CO3 edge side. Orthorhombic o-Bi5 O7 I undergoes a total reconstruction process by its phase transformation into tetragonal (BiO)2 CO3 (BOC-o) to form a well-aligned nanosheet array with maximally exposing CO3 2- moiety at the edge side. The post-reconstruction BOC-o catalyst achieved 100 % Faradaic efficiency at -0.86 V vs. RHE for CO2 -to-formate conversion. However, another conservative reconstruction of tetragonal t-BiOI into tetragonal (BiO)2 CO3 (BOC-t) exposed majorly a less reactive [BiO]+ layer. At low overpotential regions, the catalytic cycle of BOC-o begins with the initial conversion of the CO3 2- moiety into formate at the [-OBi-(CO3 )-BiO-] site, but at high overpotential regions, the [BiO]+ layer undergoes reduction to metallic Bi and multi-catalytic species proceed with CO2 reduction. Otherwise, the deactivation of Bi+ site by an organic molecule switched on another catalysis of proton reduction, preventing CO2 reduction.

Asymmetric Wettability Mediated Patterning of Single Crystalline Nematic Liquid Crystal and P-N Heterojunction Toward a Broadband Photodetector.

The well aligned and precise patterning of liquid crystals (LCs) are considered as two key challenges for large-scale and high-efficiency integrated optoelectronic devices. However, owing to the uncontrollable liquid flow and dewetting process in the conventional techniques, most of the reported research is mainly focused on simple sematic LCs, which are composed of terthiophenes or benzothieno[3, 2-b][1] benzothiophene backbone; only a few works are carried out on the complicated LCs. Herein, an efficient strategy was introduced to control the liquid flow and alignment of LCs and realized precise and high-quality patterning of A-π-D-π-A BTR, based on the asymmetric wettability interface. Through this strategy, the large-area and well-aligned BTR microwires array was fabricated, which exhibited highly ordered molecular packing and improved charge transport performance. Furthermore, the integration of BTR and PC71BM was achieved to manufacture uniform P-N heterojunction arrays, which still possessed highly ordered alignment of BTR. On the basis of these aligned heterojunction arrays, the high-performance photodetector exhibited an excellent responsivity of 27.56 A W-1 and a specific detectivity of 2.07 × 1012 Jones. This research not only provides an efficient strategy for the fabrication of aligned micropatterns of LCs but also gives a novel insight for the fabrication of high-quality micropatterns of the P-N heterojunction toward integrated optoelectronics.

Biomimetic bone tissue structure: An ultrastrong thermal energy storage wood

Phase change material (PCM) with thermal energy storage capacity and automatic temperature regulation hold tremendous potential for construction energy conservation. However, conventional PCMs often exhibits liquid leakage, volume change and insufficient mechanical property, which are prone to load-bearing accidents, hindering their application as an engineering building material. Herein, inspired by the oriented “brick-and-mortar” structure in bone, we report a facile strategy to develop a form-stable, ultrastrong and highly energy-stored composite wood-based PCM (PWPCM) via in-situ polymerization of polyurethane-based PCM using hierarchically well-aligned wood as bio-template. PWPCM showed high tensile strength of 81.9 MPa and elastic modulus of 10.2 GPa along the longitudinal direction due to the well-aligned cellulose nanofibrils arrays and the “brick-and-mortar” structure based on strong intermolecular bonding between cellulose and PCM chains, as confirmed by molecular dynamic simulations. PWPCM was 73.4 times stronger than pure PCM, and 4–40 times as high as most conventional PCMs ever reported, representing one of the strongest composite PCMs. Benefited from the high-loading PCM, PWPCM showed wide phase transition temperature range and high enthalpy of 116.1 J/g, together with outstanding temperature regulation and shape-stability. This work provides a promising strategy for fabricating low-cost, eco-friendly, strong wood-based PCM for energy-saving construction and intelligent agriculture.

A retinomorphic neuron for artificial vision and iris accommodation.

The iris of an eye automatically optimizes the amount of light that strikes the retina by accommodating the intensity of ambient light. Here, we describe a retinomorphic neuron using neuromorphic photoreceptors for artificial vision and iris accommodation that mimics the biological structure and processing functions of retinal neurons for light sensing and signal transduction. The system consists of a neuromorphic photoreceptor, an electrochromic device as a light filter, and a spike-generation unit. In particular, the Au nanoparticle (NP) decorated ITO fiber photoreceptor with a well-aligned array structure is able to rely on its own light-tunable synaptic plasticity and the plasmon-enhanced light absorption. Therefore, it allows real-time feedback about light intensity, emits a higher-frequency electrical stimulus to stronger light, flash, or prolonged light illumination time, and drives the electrochromic filter to work, allowing mild light to pass through. Compared with traditional artificial irises or artificial photoreceptors, our design introduces neural pathways and neuromorphic devices, which are closer to biological functions in simulation. To our knowledge, this is the first time that a retinal neuron with neuromorphic photoreceptors has been used for artificial iris vision. Furthermore, we demonstrate direct and consensual pupillary light reflexes. The design of artificial iris vision has potential applications in biomimetic engineering, smart interaction, and visual prostheses.

An ordered conductive Ni-CAT nanorods array as all-round polysulfide regulator for lithium-sulfur batteries

The effective suppression of polysulfide shuttle is indispensable for the commercialization of lithium-sulfur batteries (LSBs). In this work, an ordered conductive metal-organic framework (MOF) Ni-CAT nanorods array rooted on carbon nanotube film (Ni-CAT/CNTF) is proposed for this subject. The well-aligned MOF nanorods array possesses a unique vertical structure, presenting an incompact upper part and dense root, which guarantee the highly efficient adsorption and selective sieving towards polysulfides, respectively, as well as a fast Li+ transfer. What's more, the good electrical property and fully exposed Ni-based catalytic sites are qualified to boost the electrochemical kinetics. Consequently, LSBs with this fully functional MOF nanorods array exhibit an astonishing capacity of 1087 mAh g−1 and an extraordinary cyclability with a finite capacity-fading of only 0.026% per cycle for 1000 cycles at 1 C, along with an exceptional rate performance of 754 mAh g−1 at 5 C. Moreover, outstanding cycle and rate performance can be maintained under elevated sulfur loadings with a reduced electrolyte content. This work offers new insights into the rational design of polyfunctional nanostructures in LSBs.

Sub-10 nm Corrugated TiO2 Nanowire Arrays by Monomicelle-Directed Assembly for Efficient Hole Extraction.

Precise synthesis of well-ordered ultrathin nanowire arrays with tunable active surface, though attractive in optoelectronics, remains challenging to date. Herein, well-aligned sub-10 nm TiO2 nanowire arrays with controllable corrugated structure have been synthesized by a unique monomicelle-directed assembly method. The nanowires with an exceptionally small diameter of ∼8 nm abreast grow with an identical adjacent distance of ∼10 nm, forming vertically aligned arrays (∼800 nm thickness) with a large surface area of ∼102 m2 g-1. The corrugated structure consists of bowl-like concave structures (∼5 nm diameter) that are closely arranged along the axis of the ultrathin nanowires. And the diameter of the concave structures can be finely manipulated from ∼2 to 5 nm by simply varying the reaction time. The arrays exhibit excellent charge dynamic properties, leading to a high applied bias photon-to-current efficiency up to 1.4% even at a very low potential of 0.41 VRHE and a superior photocurrent of 1.96 mA cm-2 at 1.23 VRHE. Notably, an underlying mechanism of the hole extraction effect for concave walls is first clarified, demonstrating the exact role of concave walls as the hole collection centers for efficient water splitting.

PH Controlled Nanostructure and Optical Properties of ZnO and Al-Doped ZnO Nanorod Arrays Grown by Microwave-Assisted Hydrothermal Method.

The low-temperature microwave-assisted hydrothermal method was used to successfully grow pure and Al-doped ZnO (AZO) nanorod (NR) arrays on glass substrates. The combined effects of doping and pH on the structural properties, surface chemistry, and optical properties of all samples were investigated. Thermodynamic-based simulations of the growth solution were performed and a growth mechanism, that considers the effects of both the pH and Al-doping, is proposed, and discussed. Tuning the solution pH is key parameter to grow well-aligned, single crystal, highly packed, and high aspect ratio nanorod arrays. Moreover, the optical absorption in the visible range is enhanced by controlling the pH value. The PL spectra reveal a shift of the main radiative emission from the band-to-band into a transition involving deep defect levels of Zinc interstitial Zni. This shift is caused by an enhancement of the non-radiative components (phonon relaxation) at high pH values. The production of well-ordered ZnO and AZO nanorod arrays with visible-active absorption/emission centers would increase their potential use in various applications.

Hydrothermal growth and ultraviolet sensing performance of well-aligned Ga-doped ZnO nanowire arrays

Herein, gallium (Ga)-doped zinc oxide (ZnO) nanowire arrays (GZNWAs) with different Ga doping concentrations (Ga/Zn = 0–4 atom%) were grown on the interdigital patterned fluoro-doped tin oxide glass substrates by a hydrothermal technique, their crystalline structure, morphology and ultraviolet (UV) sensing performance were focused on investigating. The results showed that all the as-grown samples were hexagonal wurtzite structure of ZnO. When the Ga doping concentration was below 4%, well-aligned GZNWAs were achieved. Furthermore, five UV photodetectors (PDs) were prepared using the GZNWAs as photoactive layers, all the devices were found to be excellent responses towards 365 nm light. Among these devices, the GZNWAs UV PD (1% Ga) maintained the optimal performance, its responsivity, sensitivity, detectivity, external quantum efficiency, response time and decay time were 72.8 A/W at 5 V, 747.8 at 0 V, 5.5 × 1012 Jones, 2.5 × 104%, 10.6 s and 45.6 s, respectively.

Electrocatalytic degradation of methyl orange and 4-nitrophenol on a Ti/TiO2-NTA/La-PbO2 electrode: electrode characterization and operating parameters.

The anode material plays a crucial role in the process of electrochemical oxidation. Herein, a TiO2 nanotube arrays (TiO2-NTA) intermediate layer and La-PbO2 catalytic layer were synthesized on a Ti surface by the electrochemical anodic oxidation and electrochemical deposition technology, respectively. The prepared Ti/TiO2-NTA/La-PbO2 electrode was used as an electrocatalytic oxidation anode for pollutant degradation. Scanning electron microscopy (SEM) analysis showed that the TiO2-NTA layer possessed a highly ordered and well-aligned nanotube array morphology, and the La-PbO2 layer with angular cone cluster was uniform and tightly bonded. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis indicated that the intermediate layer primarily consisted of the anatase crystal structure of TiO2 and the catalyst layer was made of La-PbO2. Electrochemical analysis revealed that Ti/TiO2-NTA/La-PbO2 electrode exhibited higher oxidation peak current, electrochemical active surface area, and oxygen evolution potential (OEP, 1.64V). Using methyl orange and 4-nitrophenol as model pollutants, electrocatalytic properties of the prepared Ti/TiO2-NTA/La-PbO2 electrode were systematically investigated under different conditions, and the electrochemical degradation fitted well with the pseudo-first-order kinetics model. Efficient anodic oxidation of model pollutants was mainly attributed to the indirect oxidation mediated by hydroxyl radicals (•OH). The total organic carbon (TOC) removal efficiency of methyl orange and 4-nitrophenol was 70.2 and 72.8%, and low energy consumption (2.50 and 1.89 kWh g-1) was achieved after 240min of electrolysis under the conditions of initial concentration of model pollutant, electrode spacing, and electrolyte concentration were 50mg L-1, 2cm, and 0.1mol L-1, respectively. This work provided a new strategy to develop the high-efficiency electrode for refractory pollutants degradation.

Significant improvement in the performance of well-aligned ZnO nanowire arrays ultraviolet photodetector by Ga doping

The low-cost ultraviolet photodetectors (UV PDs) with high performance have wide applications in many important fields, herein, both well-aligned zinc oxide nanowire arrays (ZNWAs) and gallium (Ga)-doped ZNWAs (GZNWAs, Ga/Zn = 1 atom%) UV PDs were fabricated by a hydrothermal technique, their performances were analyzed in detail. The results showed that the GZNWAs UV PD exhibited an excellent response to 365 nm light, its response time (Tr), decay time (Td), responsivity (Rλ), sensitivity (S), detectivity (D⁎) and external quantum efficiency (EQE) were 9.8 s, 45.8 s, 72.8 A/W at 5 V, 747.8 at 0 V, 5.5 × 1012 Jones and 2.5 × 104%, respectively. By comparison, the performances of GZNWAs UV PD were much better than those of ZNWAs UV PD, we found that Ga doping played a key role on improving the performances of ZNWAs-based UV PDs

Single-Crystalline Thin-Film Memory Arrays of Molecular Ferroelectrics with Ultralow Operation Voltages

Though most of the recently developed molecular ferroelectrics (MFs) exhibit excellent ferroelectric properties, the practical applications are still impeded by the limited polarization axes, poor processing capability for a high-quality thin film, and the incompatibility with matured lithography techniques for microelectronics. Here, we successfully demonstrated MF-based single-crystalline microdevice arrays using a lithography-compatible, solution-processed strategy that can avoid the above-mentioned obstacles at one time, i.e., dewetting-assisted patterning crystallization strategy. As a protype, uniform and well-aligned single-crystalline thin-film arrays of multiaxial MF [3-oxoquinuclidinium]ClO4 ([3-O-Q]ClO4) are prepared. Owing to the well-aligned crystallographic orientation and polarization direction, the obtained single-crystalline nonvolatile memory (NVM) arrays can exhibit an ultralow operating voltage of ∼1.6 V and long endurance cycles of 106, which are superior to other organic NVM devices. This work implies a promising route to high-density single-crystalline memory arrays for data storage, especially for low-cost flexible electronics.