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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Este trabalho foi financiado pela Fundação Nacional de ciências naturais da China (n. Grant 11402221 e 11502224), a simulação de estado chave laboratório de intensa pulsada radiação e efeito (SKLIPR1513) e Hunan Provincial chave pesquisa e plano de desenvolvimento (n. º 2016 WK 2014).

1. fabricação de filmes finos de PZT flexível
<ol><li>Corte um substrato de mica de 1 x 1 cm de uma folha de mica com uma tesoura.</li>
	<li>Consertar este substrato de mica de 1 x 1 cm sobre uma mesa usando fita dupla-face.</li>
	<li>Use uma pinça para peel-off a mica camada por camada até a espessura desejada (50 µm), medida com um micrômetro.</li>
	<li>Cole-o na hora clivada substrato mica sobre um suporte de substrato 5 ' usando uma fina camada de tinta prateada e curá-la a 120 ° C, em uma chapa quente durante 10 minutos para apor mica em substrato com firmeza.</li>
	<li>Colocar o suporte de substrato PLD (deposição de Laser pulsado) na câmara de PLD.</li>
	<li>Selecione a taxa de repetição (por exemplo, 10 Hz) e energia (por exemplo, 300 mJ) a laser.</li>
	<li>Mova a lente de focalização para a posição definida.</li>
	<li>Abrir o obturador e depositar um 5 nm CoFe2O4 (CFO) [Laser energia: 300 mJ, pressão do oxigênio: 50 mTorr, temperatura da amostra: 590 ° C, tempo de deposição: 5min] a película fina como uma camada de buffer por disparo do laser (Figura 1).</li>
	<li>Depositar uma 20-80 nm SrRuO3 (SRO) [Laser energia: 300 mJ, pressão do oxigênio: 100 mTorr, temperatura da amostra: 680 ° C, tempo de deposição: 10-30 min] sobre a camada de buffer CFO como o eletrodo inferior para testes elétricos subsequentes provocando o laser ( A Figura 1).</li>
	<li>Depósito de 150 nm PZT [Laser energia: 300 mJ, pressão do oxigênio: 100 mTorr, temperatura da amostra: 650 ° C, tempo de deposição: 60 min] fino filme no topo do eletrodo inferior de SRO por disparo do laser (Figura 1).</li>
	<li>Ventilar a câmara usando N2 e retire a amostra PZT/mica (Figura 2) quando a temperatura atinge a temperatura ambiente.</li>
	<li>Colocar a amostra em um pedaço de vidro.</li>
	<li>Coloca uma malha preconcebida com 200 µm de diâmetro na parte superior da amostra. Corrigir a malha bem e colocar a malha-amostra na câmara de sputtering.</li>
	<li>Use o DC que sputtering (10 mA, 8 mbar, 6 min) para depositar Pt top eletrodos sobre o filme. Retire a amostra após a pulverização catódica.</li>
	<li>Use uma faca ou 20% ácido de HF para remover uma seção PZT 1 x 1 mm. Isto é descobrir o eléctrodo de SRO inferior e formar muitos pequenos flexíveis capacitores ferroelétricos. Nota: Crescer SRO como o eletrodo de fundo e em seguida depositar Pt no topo os eléctrodos nas películas por pulverização catódica para formar muitos capacitores de pequenas de DC para medir as propriedades eletrônicas do filme fino PZT, mostrada na Figura 3.</li>
	<li>Pinte uma camada de prata condutor sobre o SRO exposta para aumentar a condutividade elétrica do eletrodo inferior SRO. Certifique-se de que a prata condutora pode contactar o SRO exposta.</li>
</ol>2. ferroelétrica caracterização
<ol><li>Ensaio de flexão<ol>
<li>Na parte de trás da amostra flexível, Cole um pedaço de papel com o mesmo tamanho que a amostra para fácil transferência da amostra de uma fase para outra.</li>
		<li>Coloque o PZT/mica sobre a placa de teste do analisador de dispositivo de sistema e semicondutores ferroelétricos teste.</li>
		<li>Colocar uma sonda de medição do analisador de dispositivo de sistema e semicondutores ferroelétricos teste sobre o eletrodo de topo Pt e colocar outra sonda de medição sobre a camada de prata-SRO para obter os campo de polarização-elétrico (P-E) laços de histerese e curvas de capacitância elétrica campo (C-E), enquanto a amostra está unbent.<ol>
<li>Medir os laços de histerese P-E com as duas sondas em uma frequência de 2 kHz e em 4 curvas V. medida o C-E com as duas sondas em uma frequência de 1 MHz e 4 V. remover a amostra unbent.</li>
		</ol>
</li>
		<li>Fixe a flexível PZT/mica fina película sobre o molde desejado usando fita dupla-face. Tome cuidado para evitar o escorregamento/planando de mica durante a medição.</li>
		<li>Montá-lo no Conselho do analisador de dispositivo de sistema e semicondutores ferroelétricos teste teste.</li>
		<li>Coloque uma sonda do eletrodo de topo Pt enquanto a outra sonda toca o eletrodo de SRO inferior através da prata revestimento semelhante à configuração usada anteriormente (etapa 2.1.3).</li>
		<li>Medir o P-E histerese loops e curvas de C-E sob vários elástica e compressiva dobra raios (Figura 4).<ol>
<li>Medir os laços de histerese P-E com as duas sondas em uma frequência de 2 kHz e 4 curvas de medida V. o C-E com as duas sondas em uma frequência de 1 MHz e 4 V.</li>
		</ol>
</li>
		<li>Retire a amostra PZT flexível quando completam-se as medições P-E e C-E.</li>
	</ol>
</li>
	<li>Estabilidade térmica<ol>
<li>Colocar o PZT/mica na placa teste do analisador de dispositivo de sistema e semicondutores ferroelétricos teste.</li>
		<li>Coloque uma sonda de medição sobre o eletrodo superior do Pt e outra sonda de medição sobre a camada de prata-SRO.</li>
		<li>Abra o sistema de controle de temperatura para aquecer a amostra.</li>
		<li>Realizar as medições P-E e C-E a diferentes temperaturas (25 ° C, 50 ° C, 75 ° C, 100 ° C, 125 ° C, 150 ° C, 175 ° C).</li>
		<li>Desligue o conjunto aquecedor após as medições são feitas.</li>
	</ol>
</li>
	<li>Flexão de cyclability de testes<ol>
<li>Monte o PZT flexível/mica nas duas ranhuras desta configuração.</li>
		<li>Fixe uma extremidade da amostra enquanto está dobrada da outra extremidade com o auxílio de um motor.</li>
		<li>Use uma régua para medir o comprimento PZT/mica juntamente com a direção do movimento (dobra) do motor antes da 8 mm, dobra o processo (Figura 5).</li>
		<li>Calcule o comprimento de movimento C para dobrar a amostra de 5 mm de acordo com a fórmula: C=L-2Rsin(L/2R), onde L é o comprimento de PZT/mica no estado unbent, R é os raios de curvatura, e C é o comprimento do movimento do motor.</li>
		<li>Definir o número de ciclos (1000) de flexão no computador (Figura 6).</li>
		<li>Clique no botão Iniciar (Figura 6) para iniciar o movimento motor e para trás.</li>
		<li>Retirar a amostra e medir o P-E para verificar se as propriedades ferroelétricos são retidas.</li>
	</ol>
</li>
</ol>

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Os autores têm sem interesses financeiros concorrentes para divulgar.

A etapa chave na fabricação de elementos condutores reside na utilização de uma superfície limpa e até mesmo/plano de substrato. Apesar de superfície de mica clivada recém atomicamente liso, é necessário prestar atenção ao impedindo que superfícies sofrem fragmentação visível, dividir camadas, inclusões, fissuras, etc após a deposição da camada de PZT, a amostra foi esfriada sob uma pressão de oxigênio alta (200-500 Torr) para reduzir as vagas de oxigênio. Ex situ eléctrodos de p...

A sucesso fabricação de elementos de memória não-volátil flexível (NVME) desempenha um papel fundamental em explorar todo o potencial da eletrônica flexível. NVME serão dispõem de pouco peso, consumo de baixo custo, baixa potência, velocidade e capacidades de armazenamento de alta densidade além de armazenamento de dados, processamento de informação e comunicação. Perovskita Pb (Zr, Ti) O3 (PZT) atua como um sistema popular para tais aplicações, considerando sua grande polarização, polarização rápida comutação, alta temperatura de Curie, coerciva de baixa e Alto coeficiente piezoelétrico. Memória não-volátil ferroelétricos, um pulso de tensão externa pode alternar as polarizações de dois remanescentes entre duas direções estáveis, representadas por '0' e '1'. É não-volátil, e o processo de leitura/gravação pode ser concluído dentro de nanossegundos. NVME baseado no orgânico1,2,3,4,5,6 e inorgânicos7,8,9,10 ,11,12,13,14,15 materiais ferroelétricos têm sido tentadas em substratos flexíveis. No entanto, tal integração é limitada por não somente dos substratos incapacidade de crescimento de alta temperatura, mas também o desempenho do dispositivo degradadas, correntes de fuga e curto-circuito elétrico devido a sua superfície mais áspera. Apesar de resultados promissores, alternam estratégias como o afinamento do substrato8 e a transferência de camada epitaxial sobre um substrato flexível15 sofrer viabilidade restrita, tendo em conta o sofisticado processo de várias etapas, a imprevisibilidade de transferência e a aplicabilidade limitada.
Pelas razões acima mencionadas, é fundamental para explorar um substrato adequado que é capaz de superar o limitado estabilidades térmicas e operacionais de substratos moles para avançar ainda mais eletrônica flexível. Uma mica moscovita natural (KAl2(10de AlSi3O) (OH)2) substrato com características únicas como atomicamente suavizar superfícies, alta estabilidade térmica, inércia química, alta transparência, flexibilidade mecânica, e compatibilidade com os métodos de fabricação atual pode ser usada para efetivamente lidar com estas questões. Mais ainda, a estrutura em camadas bidimensional de mica monoclínico suporta Epitaxia de van der Waals, que atenua a treliça e térmico correspondentes condições, suprimindo assim significativamente o substrato efeito de aperto. Estas vantagens foram exploradas no crescimento direto de óxidos funcional16,17,18,19,20,21,22, 23 na moscovita recentemente, tendo em conta os aplicativos de dispositivo flexível.
Aqui, descrevemos um protocolo para crescer diretamente filmes finos da epitaxial chumbo ainda flexível zircónio titanato (PZT) na mica moscovita. Isto é conseguido através de um processo de deposição de laser pulsado baseando-se nas propriedades versátil de mica, resultando em heteroepitaxy de van der Waals. Tais estruturas fabricadas reter todas as propriedades superiores de PZT epitaxial em substratos cristalinos único rígidos e apresenta excelente estabilidade térmica e mecânica. Esta abordagem simples e confiável fornece uma vantagem tecnológica sobre a transferência de várias etapas e estratégias de desbaste de substrato e facilita o desenvolvimento de elementos tão aguardado single-cristalino ainda flexível memória não-volátil pré-requisito para próxima geração dispositivos inteligentes com alto desempenho.

<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

Flexíveis não-volátil memórias têm recebido muita atenção como eles são aplicáveis para portátil dispositivo eletrônico inteligente no futuro, contando com recursos de baixa potência consumo e armazenamento de dados de alta densidade. No entanto, a memória não-volátil de óxido de alta qualidade com base em substratos flexíveis frequentemente é limitada pelas características da materiais e o processo de fabricação de alta temperatura inevitável. Neste trabalho, propõe-se um protocolo diretamente crescimento epitaxial ainda flexível chumbo zircónio titanato memória elemento na mica moscovita. O método de técnica e medição de deposição versáteis permitem a fabricação de elementos de memória não-volátil de flexível ainda single-cristalino necessárias para a próxima geração de dispositivos inteligentes.

Os filmes finos de PZT/SRO/CFO/mica epitaxiais foram depositados com a técnica de deposição de laser pulsado, conforme descrito na etapa 1. A Figura 1 mostra o esquema de crescimento e a Figura 2 mostra um elemento real de NVM flexível baseado no PZT.

Estabilidade mecânica é um aspecto crucial do aplicativo de dispositivo flexível. O desempenho ferroelét...

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

Neste trabalho, apresentamos um protocolo diretamente crescer um epitaxial ainda elemento de memória de titanato de zircônio chumbo flexível na mica moscovita.

Um método de medição para um elemento ferroelétrica flexível baseado em Heteroepitaxy de Van Der Waals e fabricação

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

a-fabrication-measurement-method-for-flexible-ferroelectric-element

Universidad de Cartagena UDEC

Research

JoVE Journal

Engineering

8.2K visualizações.  Xiangtan University. Neste trabalho, apresentamos um protocolo diretamente crescer um epitaxial ainda elemento de memória de titanato de zircônio chumbo flexível na mica moscovita.

Vídeo: 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.

Fabricação de óxidos complexos espacialmente confinados

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

Engenharia

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.

Crescimento por pulverização catódica e Caracterização de metamagnética ordenou-B2 Ferh Epilayers

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.

Chemical Vapor Deposition de um ímã Orgânica, vanádio 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.

Métodos experimentais avançados para baixa temperatura Magnetotransporte Medição de novos materiais

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.

Crescimento epitaxial de Perovskita titanato de estrôncio em Germânio via deposição de camadas Atomic

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.

Fabricação de imagem flexível Sensor baseado no NIPIN Lateral Phototransistors

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.

Granel e síntese de película fina de óxidos de entropia-estabilizado em termos de composição variantes

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.

Um método padrão e confiável para fabricar 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.

Medir a polarização ferroelétrica magneticamente sintonizado em cristais 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.

Fabricando Van der Waals Heterostructures com alinhamento rotativo preciso

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