Name: a fabrication and measurement method for a flexible ferroelectric element based on van der waals heteroepitaxy
Uploaded: 2018-04-08T14:00:00.000+00:00
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Description: Watch this Scientific Journal Video about A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy at JoVE.com

Este trabajo fue financiado por la Fundación Nacional de Ciencias naturales de China (Grant no. 11402221 y 11502224), la simulación de estado clave laboratorio de intensa pulsada la radiación y efecto (SKLIPR1513) y Hunan Provincial clave de investigación y Plan de desarrollo (no. 2016 WK 2014).

1. fabricación de películas delgadas de PZT Flexible
<ol><li>Corte un substrato de mica de 1 cm x 1 cm de una hoja de mica con tijeras.</li>
	<li>Fijar este substrato de mica de 1 cm x 1 cm en un escritorio usando cinta de doble cara.</li>
	<li>Utilice unas pinzas para pelar apagado la mica capa-por-capa hasta el espesor deseado (50 μm), medida con un micrómetro.</li>
	<li>Pegue esto recién troceados substrato de mica en un portamuestras de sustrato de 5'' con una fina capa de pintura plateada y curar a 120 ° C sobre una placa caliente por 10 minutos fijar firmemente la mica en el substrato.</li>
	<li>Ponga el soporte del sustrato PLD (Pulsed Laser Deposition) en la cámara PLD.</li>
	<li>Seleccione la tasa de repetición (p. ej., 10 Hz) y laser (p. ej., 300 mJ) de energía.</li>
	<li>Mover la lente de enfoque a la posición.</li>
	<li>Abra el obturador y depositar 5 nm CoFe2O4 (CFO) [energía del Laser: 300 mJ, presión de oxígeno: 50 mTorr, temperatura de la muestra: 590 ° C, tiempo de deposición: 5min] película fina como una capa del almacenador intermediario mediante la activación del láser (figura 1).</li>
	<li>Depositar un 20-80 nm SrRuO3 (SRO) [energía del Laser: 300 mJ, presión de oxígeno: 100 mTorr, temperatura de la muestra: 680 ° C, tiempo de deposición: min 10-30] en la capa del almacenador intermediario del director financiero como el electrodo inferior para pruebas de rendimiento eléctrico posterior mediante la activación del láser ( Figura 1).</li>
	<li>Depósito a 150 nm PZT [energía del Laser: 300 mJ, presión de oxígeno: 100 mTorr, temperatura de la muestra: 650 ° C, el tiempo de deposición: 60 min] delgada película en la parte superior de electrodo inferior de SRO por disparo del láser (figura 1).</li>
	<li>Ventilar la cámara usando N2 y, retire la muestra PZT/mica (figura 2) cuando la temperatura alcanza la temperatura ambiente.</li>
	<li>Coloca la muestra sobre un trozo de vidrio.</li>
	<li>Poner una malla prediseñada con 200 μm de diámetro en la cima de la muestra. Fijar bien la malla y malla-muestra en la cámara de sputtering.</li>
	<li>Utilizar la C.C. que farfulla (10 mA, 8 mbar, 6 min) al depósito superior electrodos de Pt en la película. Retire la muestra después de la pulverización.</li>
	<li>Utilice un cuchillo o 20% ácido HF para eliminar una sección PZT de 1 x 1 mm. Se trata de descubrir el electrodo de SRO de fondo y forma muchos pequeños condensadores ferroeléctricos flexibles. Nota: Crecen SRO como el electrodo inferior y luego depositar Pt sobre los electrodos en las películas de DC sputtering para formar muchos pequeños condensadores para medir las propiedades electrónicas de la película fina de PZT, que se muestra en la figura 3.</li>
	<li>Pintar una capa de plata conductiva en el SRO expuesto para aumentar la conductividad del electrodo inferior SRO. Asegúrese de que la conductora de plata puede contactar con el SRO expuesto.</li>
</ol>2. Caracterización ferroeléctrico
<ol><li>Prueba de flexión<ol>
<li>En la parte posterior de la muestra flexible, pegue un pedazo de papel con el mismo tamaño que la muestra para facilitar la transferencia de la muestra de una etapa a otra.</li>
		<li>Lugar el PZT/mica en el tablero de prueba del ferroeléctrico prueba sistema y semiconductor dispositivo analizador.</li>
		<li>Poner una sonda de medición del ferroeléctrico prueba sistema y semiconductor dispositivo analizador en el electrodo superior Pt y poner la otra sonda de medición en la capa de plata-SRO a los lazos de histéresis de campo eléctrico de polarización (P-E) y curvas de campo de capacitancia eléctrica (C-E) mientras que la muestra es desplegada.<ol>
<li>Medir los lazos de histéresis P-E con las dos puntas de prueba a una frecuencia de 2 kHz y 4 curvas V. medida C-E con las dos puntas de prueba en una frecuencia de 1 MHz y 4 V. quitar la muestra desplegada.</li>
		</ol>
</li>
		<li>Asegure la capa fina flexible de PZT/mica en el molde deseado usando cinta de doble cara. Tenga cuidado para evitar el resbalamiento/deslizamiento de mica durante la medición.</li>
		<li>Montarlo en el tablero de prueba del ferroeléctrico prueba sistema y semiconductor dispositivo analizador.</li>
		<li>Poner una punta de prueba en el electrodo superior Pt mientras que la otra punta de prueba toque el electrodo de SRO de parte inferior a través de la plata capa similar a la configuración utilizada anteriormente (paso 2.1.3).</li>
		<li>Medir los lazos de histéresis E P y C E curvas debajo de vario de tracción y compresión flexión radios (figura 4).<ol>
<li>Medir los lazos de histéresis P-E con las dos sondas en una frecuencia de 2 kHz y 4 curvas V. medida C-E con las dos puntas de prueba a una frecuencia de 1 MHz y 4 V.</li>
		</ol>
</li>
		<li>Retire la muestra PZT flexible cuando finalicen las medidas P-E y C E.</li>
	</ol>
</li>
	<li>Estabilidad térmica<ol>
<li>Poner el PZT/mica en el tablero de prueba del ferroeléctrico prueba sistema y semiconductor dispositivo analizador.</li>
		<li>Poner una sonda de medición en el electrodo superior Pt y poner la otra sonda de medición de la capa de plata-SRO.</li>
		<li>Abrir el sistema de control de temperatura para calentar la muestra.</li>
		<li>Realizar las mediciones de P E y C E a diferentes temperaturas (25 ° C, 50 ° C, 75 ° C, 100 ° C, 125 ° C, 150 ° C, 175 ° C).</li>
		<li>Apague la unidad del calentador después de las mediciones.</li>
	</ol>
</li>
	<li>Flexión de etapa de pruebas<ol>
<li>Monte el PZT/mica flexible en las dos ranuras de esta configuración.</li>
		<li>Fijar un extremo de la muestra mientras está doblada desde el otro extremo con la ayuda de un motor.</li>
		<li>Utilice una regla para medir la longitud PZT/mica junto con la dirección del movimiento (flexión) del motor antes de lo 8 mm doblado proceso (figura 5).</li>
		<li>Calcular la longitud de movimiento C para la muestra de 5 mm según la fórmula de la curva: C=L-2Rsin(L/2R), donde L es la longitud de PZT/mica en estado desplegada, R es el radio de flexión, y C es la longitud de movimiento del motor.</li>
		<li>Establecer el número de ciclos (1000) de doblado en la computadora (figura 6).</li>
		<li>Haga clic en el botón de inicio (figura 6) para iniciar el movimiento del motor hacia adelante y hacia atrás.</li>
		<li>Retire la muestra y medir el P-E para comprobar si se mantienen las propiedades ferroeléctricas.</li>
	</ol>
</li>
</ol>

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Los autores tienen intereses financieros que compiten a revelar.

El paso clave en la fabricación de elementos ferroeléctricos miente en el uso de una superficie limpia y plana incluso del sustrato. Aunque la superficie recién descamada mica es atómico lisa, es necesario prestar atención a la prevención de las superficies del sufrimiento visible fragmentación, fractura de capas, grietas, inclusiones, etc. después de la deposición de la capa PZT, la muestra se enfrió bajo un oxígeno alta presión (200-500 Torr) para reducir las vacantes de oxígeno. Ex situ ...

La exitosa fabricación de elementos de memoria no volátil flexible (NVME) desempeña un papel clave en la explotación de todo el potencial de la electrónica flexible. NVME disponen de peso ligero, bajo costo, de baja potencia consumo, alta velocidad y capacidades de almacenamiento alta densidad además de almacenamiento de datos, procesamiento de la información y la comunicación. Perovskita Pb (Zr, Ti) O3 (PZT) actúa como un sistema popular para las aplicaciones teniendo en cuenta su gran polarización, polarización rápida conmutación, alta temperatura de Curie, bajo campo coercitivo y alto coeficiente piezoeléctrico. En memoria no volátil ferroeléctrico, un pulso de voltaje externo puede cambiar las polarizaciones dos remanente entre dos direcciones estables, representadas por '0' y '1'. Es no volátil, y puede completarse el proceso de lectura y escritura en nanosegundos. NVME base orgánica1,2,3,4,5,6 y inorgánicos7,8,9,10 ,11,12,13,14,15 materiales ferroeléctricos se han intentado sobre sustratos flexibles. Sin embargo, esta integración está limitada por no sólo la incapacidad de los sustratos de crecimiento de alta temperatura, pero también el rendimiento degradado, fuga de corriente y cortocircuitos debido a sus superficies más ásperas. A pesar de resultados prometedores, alternan estrategias como la reducción de sustrato8 y la transferencia de la capa epitaxial en un substrato flexible15 sufren viabilidad restringida ante el sofisticado proceso de varias fases, la imprevisibilidad de la transferencia y aplicabilidad limitada.
Por las razones ya mencionadas, es fundamental explorar un sustrato adecuado que es capaz de superar la limitada estabilidades térmicas y operacionales de substratos suaves para avanzar electrónica flexible. Una mica moscovita natural (KAl2(AlSi3O10) (OH)2) sustrato con características únicas como atómico alisar superficies, alta estabilidad térmica, inercia química, alta transparencia, flexibilidad mecánica, y compatibilidad con los métodos actuales de fabricación puede utilizarse para tratar eficazmente estas cuestiones. Más aún, la estructura de capas bidimensional de mica monoclínico apoya epitaxy de van der Waals, que mitiga el enrejado y coincidencia de condiciones, de tal modo perceptiblemente suprimir el sustrato efecto de sujeción térmico. Estas ventajas han sido explotadas en el crecimiento directo de óxidos funcionales16,17,18,19,20,21,22, 23 en mica recientemente, a la vista de aplicaciones para dispositivos flexibles.
Adjunto, describimos un protocolo para directamente crecimiento epitaxial todavía flexible plomo circonio titanato (PZT) de películas delgadas de mica moscovita. Esto se logra mediante un proceso de deposición pulsada del laser depende de las propiedades versátiles de mica, lo que resulta en heteroepitaxias de van der Waals. Tales estructuras prefabricadas conservar todas las propiedades superiores de PZT epitaxial en sustratos rígidos de cristalinos únicos y exhibe excelentes estabilidades térmicas y mecánicas. Este enfoque simple y fiable ofrece una ventaja tecnológica sobre multietapa-transferencia y estrategias de reducción de sustrato y facilita el desarrollo de elementos de la tan esperada flexible pero monocristalino memoria prerrequisitos para dispositivos inteligentes de última generación con un alto rendimiento.

<table><tbody><tr><td>&lt;strong&gt;Equipment&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>hot plate</td><td>Polish</td><td>P-20</td><td></td></tr><tr><td>PLD system</td><td>PVD products</td><td>PLD 5000</td><td></td></tr><tr><td>Ferroelectric test system&amp;nbsp;</td><td>Radiant Technologies Precisions workstations&amp;nbsp;</td><td>RT66A</td><td></td></tr><tr><td>Semiconductor device analyzer&amp;nbsp;</td><td>Agilent&amp;nbsp;</td><td>B1500A</td><td></td></tr><tr><td>Bending molds</td><td>home-made</td><td></td><td>Machined teflon material</td></tr><tr><td>Bending stage</td><td>home-built</td><td></td><td>Labview interfaced setup which provides a prescise displacemnt as small as 1 micrometer</td></tr><tr><td>Sputtering system</td><td>Beijing&amp;nbsp;Elaborate</td><td>ETD-3000</td><td></td></tr><tr><td>&lt;strong&gt;Materials&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>mica(001) sheets</td><td>Nilaco corporation&amp;nbsp;</td><td>990066</td><td></td></tr><tr><td>conductive silver paint</td><td>Ted Pella, INC</td><td>No.16033</td><td></td></tr><tr><td>CoFe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt; target</td><td>Kurt J.Lesker</td><td></td><td></td></tr><tr><td>SrRuO&lt;sub&gt;3&lt;/sub&gt; target</td><td>Kurt J.Lesker</td><td></td><td></td></tr><tr><td>PbZr&lt;sub&gt;0.2&lt;/sub&gt;Ti&lt;sub&gt;0.8&lt;/sub&gt;O&lt;sub&gt;3 &lt;/sub&gt;target</td><td>Kurt J.Lesker</td><td></td><td></td></tr><tr><td>Pt target</td><td>Hefei Ke jing</td><td></td><td></td></tr></tbody></table>

a fabrication and measurement method for a flexible ferroelectric element based on van der waals heteroepitaxy

Memorias no volátiles flexibles han recibido mucha atención como son aplicables para dispositivo electrónico inteligente portátil en el futuro, confiando en las capacidades de bajo consumo de energía y almacenamiento de datos de alta densidad. Sin embargo, la memoria no volátil de óxido de alta calidad basado en los substratos flexibles es a menudo limitada por las características del material y el proceso de fabricación de alta temperatura inevitable. En este trabajo, se propone un protocolo directamente crecimiento epitaxial pero flexible plomo circonio titanato memoria elemento de mica moscovita. El método de medición y técnica de deposición versátil permiten la fabricación de elementos de memoria no volátil flexible pero monocristalino necesarios para la próxima generación de dispositivos inteligentes.

Las películas delgadas de PZT/SRO/CFO/mica epitaxiales fueron depositadas con la técnica de deposición pulsada del laser como se indica en el paso 1. La figura 1 muestra el esquema de crecimiento y la figura 2 muestra un elemento real de NVM flexible basado en el PZT.

Estabilidad mecánica es un aspecto crucial de la aplicación de dispositivos flexibles. Se ...

Watch this Scientific Journal Video about A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy at JoVE.com

A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy

En este trabajo, presentamos un protocolo directamente creciendo un epitaxial todavía elemento de memoria de titanato de circonio de cable flexible en la mica moscovita.

Una fabricación y método de medición de un elemento ferroeléctrico Flexible basado en heteroepitaxias de Van Der Waals

Flexible non-volatile memories have received much attention as they are applicable for portable smart electronic device in the future, relying on ...

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JoVE Journal

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8.2K vistas.  Xiangtan University. En este trabajo, presentamos un protocolo directamente creciendo un epitaxial todavía elemento de memoria de titanato de circonio de cable flexible en la mica moscovita.

Video: A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy

Fabrication of Spatially Confined Complex Oxides

Complex materials such as high Tc superconductors, multiferroics, and colossal magnetoresistors have electronic and magnetic properties that arise from the inherent strong electron correlations that reside within them. These materials can also possess electronic phase separation in which regions of vastly different resistive and magnetic behavior can coexist within a single crystal alloy material. By reducing the scale of these materials to length scales at and below the inherent size of the electronic domains, novel behaviors can be exposed. Because of this and the fact that spin-charge-lattice-orbital order parameters each involve correlation lengths, spatially reducing these materials for transport measurements is a critical step in understanding the fundamental physics that drives complex behaviors. These materials also offer great potential to become the next generation of electronic devices 1-3. Thus, the fabrication of low dimensional nano- or micro-structures is extremely important to achieve new functionality. This involves multiple controllable processes from high quality thin film growth to accurate electronic property characterization. Here, we present fabrication protocols of high quality microstructures for complex oxide manganite devices. Detailed descriptions and required equipment of thin film growth, photo-lithography, and wire-bonding are presented.

We describe the use of pulsed laser deposition (PLD), photolithography and wire-bonding techniques to create micrometer scale complex oxides devices. The PLD is utilized to grow epitaxial thin films. Photolithography and wire-bonding techniques are introduced to create practical devices for measurement purposes.

La fabricación de óxidos complejos espacialmente confinados

Complex materials such as high Tc superconductors, multiferroics, and colossal magnetoresistors have electronic and magnetic properties that arise from ...

Investigación

Ingeniería

Sputter Growth and Characterization of Metamagnetic B2-ordered FeRh Epilayers

Chemically ordered alloys are useful in a variety of magnetic nanotechnologies. They are most conveniently prepared at an industrial scale using sputtering techniques. Here we describe a method for preparing epitaxial thin films of B2-ordered FeRh by sputter deposition onto single crystal MgO substrates. Deposition at a slow rate onto a heated substrate allows time for the adatoms to both settle into a lattice with a well-defined epitaxial relationship with the substrate and also to find their proper places in the Fe and Rh sublattices of the B2 structure. The structure is conveniently characterized with X-ray reflectometry and diffraction and can be visualised directly using transmission electron micrograph cross-sections. B2-ordered FeRh exhibits an unusual metamagnetic phase transition: the ground state is antiferromagnetic but the alloy transforms into a ferromagnet on heating with a typical transition temperature of about 380 K. This is accompanied by a 1% volume expansion of the unit cell: isotropic in bulk, but laterally clamped in an epilayer. The presence of the antiferromagnetic ground state and the associated first order phase transition is very sensitive to the correct equiatomic stoichiometry and proper B2 ordering, and so is a convenient means to demonstrate the quality of the layers that can be deposited with this approach. We also give some examples of the various techniques by which the change in phase can be detected.

A method to prepare epitaxial layers of ordered alloys by sputtering is described. The B2-ordered FeRh compound is used as an example, as it displays a metamagnetic transition that depends sensitively on the degree of chemical order and the exact composition of the alloy.

Crecimiento catódica y caracterización de Metamagnetic B2-ordenó Ferh epicapas

Chemically ordered alloys are useful in a variety of magnetic nanotechnologies. They are most conveniently prepared at an industrial scale using ...

Chemical Vapor Deposition of an Organic Magnet, Vanadium Tetracyanoethylene

Recent progress in the field of organic materials has yielded devices such as organic light emitting diodes (OLEDs) which have advantages not found in traditional materials, including low cost and mechanical flexibility. In a similar vein, it would be advantageous to expand the use of organics into high frequency electronics and spin-based electronics. This work presents a synthetic process for the growth of thin films of the room temperature organic ferrimagnet, vanadium tetracyanoethylene (V[TCNE]x, x~2) by low temperature chemical vapor deposition (CVD). The thin film is grown at &#60;60 &#176;C, and can accommodate a wide variety of substrates including, but not limited to, silicon, glass, Teflon and flexible substrates. The conformal deposition is conducive to pre-patterned and three-dimensional structures as well. Additionally this technique can yield films with thicknesses ranging from 30 nm to several microns. Recent progress in optimization of film growth creates a film whose qualities, such as higher Curie temperature (600 K), improved magnetic homogeneity, and narrow ferromagnetic resonance line-width (1.5 G) show promise for a variety of applications in spintronics and microwave electronics.

We present the synthesis of the organic-based ferrimagnet vanadium tetracyanoethylene (V[TCNE]x, x~2) via low temperature chemical vapor deposition (CVD). This optimized recipe yields an increase in Curie temperature from 400 K to over 600 K and a dramatic improvement in magnetic resonance properties.

Deposición de vapor químico de un imán Orgánica, vanadio tetracianoetileno

Recent progress in the field of organic materials has yielded devices such as organic light emitting diodes (OLEDs) which have advantages not found in ...

Química

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T.

We describe the methodology of mechanical exfoliation and deposition of flakes of novel materials with micron-sized dimensions onto substrate, fabrication of experimental device structures for transport experimentation, and the magnetotransport measurement in a dry helium close-cycle cryostat at temperatures down to 0.300 K and magnetic fields up to 12 T.

Avanzados métodos experimentales para baja temperatura magnetotransporte Medición de Nuevos Materiales

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film ...

Epitaxial Growth of Perovskite Strontium Titanate on Germanium via Atomic Layer Deposition

Atomic layer deposition (ALD) is a commercially utilized deposition method for electronic materials. ALD growth of thin films offers thickness control and conformality by taking advantage of self-limiting reactions between vapor-phase precursors and the growing film. Perovskite oxides present potential for next-generation electronic materials, but to-date have mostly been deposited by physical methods. This work outlines a method for depositing SrTiO3 (STO) on germanium using ALD. Germanium has higher carrier mobilities than silicon and therefore offers an alternative semiconductor material with faster device operation. This method takes advantage of the instability of germanium's native oxide by using thermal deoxidation to clean and reconstruct the Ge (001) surface to the 2&#215;1 structure. 2-nm thick, amorphous STO is then deposited by ALD. The STO film is annealed under ultra-high vacuum and crystallizes on the reconstructed Ge surface. Reflection high-energy electron diffraction (RHEED) is used during this annealing step to monitor the STO crystallization. The thin, crystalline layer of STO acts as a template for subsequent growth of STO that is crystalline as-grown, as confirmed by RHEED. In situ X-ray photoelectron spectroscopy is used to verify film stoichiometry before and after the annealing step, as well as after subsequent STO growth. This procedure provides framework for additional perovskite oxides to be deposited on semiconductors via chemical methods in addition to the integration of more sophisticated heterostructures already achievable by physical methods.

This work details the procedures for the growth and characterization of crystalline SrTiO3 directly on germanium substrates by atomic layer deposition. The procedure illustrates the ability of an all-chemical growth method to integrate oxides monolithically onto semiconductors for metal-oxide semiconductor devices.

Crecimiento epitaxial de perovskita del titanato de estroncio en el germanio a través de deposición de capas atómicas

Atomic layer deposition (ALD) is a commercially utilized deposition method for electronic materials. ALD growth of thin films offers thickness control and ...

Fabrication of Flexible Image Sensor Based on Lateral NIPIN Phototransistors

Flexible photodetectors have been intensely studied for the use of curved image sensors, which are a crucial component in bio-inspired imaging systems, but several challenging points remain, such as a low absorption efficiency due to a thin active layer and low flexibility. We present an advanced method to fabricate a flexible phototransistor array with an improved electrical performance. The outstanding electrical performance is driven by a low dark current owing to deep impurity doping. Stretchable and flexible metal interconnectors simultaneously offer electrical and mechanical stabilities in a highly deformed state. The protocol explicitly describes the fabrication process of the phototransistor using a thin silicon membrane. By measuring I-V characteristics of the completed device in deformed states, we demonstrate that this approach improves the mechanical and electrical stabilities of the phototransistor array. We expect that this approach to a flexible phototransistor can be widely used for the applications of not only next-generation imaging systems/optoelectronics but also wearable devices such as tactile/pressure/temperature sensors and health monitors.

We present a detailed method to fabricate a deformable lateral NIPIN phototransistor array for curved image sensors. The phototransistor array with an open mesh form, which is composed of thin silicon islands and stretchable metal interconnectors, provides flexibility and stretchability. The parameter analyzer characterizes the electrical property of the fabricated phototransistor.

Fabricación del Sensor de imagen Flexible basado en Lateral NIPIN fototransistores

Flexible photodetectors have been intensely studied for the use of curved image sensors, which are a crucial component in bio-inspired imaging systems, ...

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides

Here, we present a procedure for the synthesis of bulk and thin film multicomponent (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (Co variant) and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O (Cu variant) entropy-stabilized oxides. Phase pure and chemically homogeneous (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (x = 0.20, 0.27, 0.33) and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O (x = 0.11, 0.27) ceramic pellets are synthesized and used in the deposition of ultra-high quality, phase pure, single crystalline thin films of the target stoichiometry. A detailed methodology for the deposition of smooth, chemically homogeneous, entropy-stabilized oxide thin films by pulsed laser deposition on (001)-oriented MgO substrates is described. The phase and crystallinity of bulk and thin film materials are confirmed using X-ray diffraction. Composition and chemical homogeneity are confirmed by X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. The surface topography of thin films is measured with scanning probe microscopy. The synthesis of high quality, single crystalline, entropy-stabilized oxide thin films enables the study of interface, size, strain, and disorder effects on the properties in this new class of highly disordered oxide materials.

The synthesis of high quality bulk and thin film (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O entropy-stabilized oxides is presented.

A granel y síntesis de la película fina de composición variantes óxidos entropía estabilizada

Here, we present a procedure for the synthesis of bulk and thin film multicomponent (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (Co variant) and ...

A Standard and Reliable Method to Fabricate Two-Dimensional Nanoelectronics

Two-dimensional (2D) materials have attracted huge attention due to their unique properties and potential applications. Since wafer scale synthesis of 2D materials is still in nascent stages, scientists cannot fully rely on traditional semiconductor techniques for related research. Delicate processes from locating the materials to electrode definition need to be well controlled. In this article, a universal fabrication protocol required in manufacturing nanoscale electronics, such as 2D quasi-heterojunction bipolar transistors (Q-HBT), and 2D back-gated transistors are demonstrated. This protocol includes the determination of material position, electron beam lithography (EBL), metal electrode definition, et al. A step by step narrative of the fabrication procedures for these devices are also presented. Furthermore, results show that each of the fabricated devices has achieved high performance with high repeatability. This work reveals a comprehensive description of process flow for preparing 2D nano-electronics, enables the research groups to access this information, and pave the way toward future electronics.

The article aims to introduce a standard and reliable fabrication procedure for the development of future low dimensional nanoelectronics.

Un método estándar y fiable para la fabricación nanoelectrónica bidimensional

Two-dimensional (2D) materials have attracted huge attention due to their unique properties and potential applications. Since wafer scale synthesis of 2D ...

Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals

Materials showing coupling phenomena between magnetism and (ferro)electricity, i.e., magnetoelectric effects, have attracted a great deal of attention due to their potential applications for future device technologies such as sensors and storage. However, conventional approaches, which usually utilize materials containing magnetic metal ions (or radicals), have a major problem: only a few materials have been found to show the coupling phenomena at room temperature. Recently, we proposed a new approach to achieve room-temperature magnetoelectrics. In contrast to conventional approaches, our alternative proposal focuses on a completely different material, a &#34;liquid crystal&#34;, free from magnetic metal ions. In such liquid crystals, a magnetic field can be utilized to control the orientational state of constituent molecules and the corresponding electric polarization through magnetic anisotropy of the molecules; it is an unprecedented mechanism of the magnetoelectric effect. In this context, this paper provides a protocol to measure ferroelectric properties induced by a magnetic field, that is, the direct magnetoelectric effect, in a liquid crystal. With the method detailed here, we successfully detected magnetically-tuned electric polarization in the chiral smectic C phase of a liquid crystal at room temperature. Taken together with the flexibility of constituent molecules, which directly affects the magnetoelectric responses, the introduced method will serve to allow liquid crystal cells to acquire more functions as room-temperature magnetoelectrics and associated optical materials.

In this report, we present a protocol to examine direct magnetoelectric effects, i.e., induction of ferroelectric polarization by applying magnetic fields, in liquid crystals. This protocol provides a unique approach, supported by the softness of liquid crystals, to achieve room-temperature magnetoelectrics.

Medición de polarización ferroelectrica magnético sintonizado en cristales líquidos

Materials showing coupling phenomena between magnetism and (ferro)electricity, i.e., magnetoelectric effects, have attracted a great deal of attention due ...

Fabricating van der Waals Heterostructures with Precise Rotational Alignment

In this work we describe a technique for creating new crystals (van der Waals heterostructures) by stacking distinct ultrathin layered 2D materials. We demonstrate not only lateral control but, importantly, also control over the angular alignment of adjacent layers. The core of the technique is represented by a home-built transfer setup which allows the user to control the position of the individual crystals involved in the transfer. This is achieved with sub-micrometer (translational) and sub-degree (angular) precision. Prior to stacking them together, the isolated crystals are individually manipulated by custom-designed moving stages that are controlled by a programmed software interface. Moreover, since the entire transfer setup is computer controlled, the user can remotely create precise heterostructures without coming into direct contact with the transfer setup, labeling this technique as &#8220;hands-free&#8221;. In addition to presenting the transfer set-up, we also describe two techniques for preparing the crystals that are subsequently stacked.

In this work we describe a technique that is used to create new crystals (van der Waals heterostructures) by stacking ultrathin layered 2D materials with precise control over position and relative orientation.

Fabricación de las heteroestructuras de van der Waals con alineación rotacional precisa

In this work we describe a technique for creating new crystals (van der Waals heterostructures) by stacking distinct ultrathin layered 2D materials. We ...