Este trabalho foi parcialmente financiado por um projeto de PEPS Cellule Energie INSIS-CNRS (1D-RENOX) para ACG e pelo Governo espanhol (MAT2012-35324 e PIE-201460I004).

1. Preparação do Sol <ol><li> Prepara-se uma solução de orto-silicato de tetraetilo prehydrolyzed (TEOS) no dia anterior à preparação das películas de gel num exaustor de fumos, em que uma balança de laboratório e um agitador magnético são colocados. Nesta etapa e durante todo o protocolo usar um jaleco, luvas e óculos de segurança. <ol><li> Em um copo de 50 mL contendo uma barra de agitação magnética revestida a Teflon pesar 1,68 g de CTAB, adicionar 48,13 ml de etanol e 3,00 ml de HCl a 35%, cobrir o copo com um vidro de relógio e agita-se até que o CTAB é completamente dissolvido. </li><li> Adicionar 7,37 ml de TEOS, gota a gota ao copo (a uma taxa de cerca de 1-2 gotas por segundo), enquanto se agitava, cobrir o frasco com um vidro de relógio e deixar agitar S / N. </li></ol></li><li> No dia seguinte, preparar uma solução aquosa 1 M de Sr 2+. Executar esta e as seguintes etapas pouco antes da preparação das películas de gel, porque uma solução envelhecida é propenso a re-precipitação do sal Sr. <ol><li> Pesar 6,6654 g de SrCl2 · 6H 2 O em um balão volumétrico de 25 ml. </li><li> Adicionar água ultrapura (por exemplo, Milli-Q) até 25 ml (menisco tangente à marca de balão) e tapar o balão com uma tampa de plástico e agite o frasco para dissolver o cloreto de estrôncio. </li></ol></li><li> Adicionar 2 ml de solução aquosa 1 M de Sr 2+ para a proveta de vidro de 50 ml contendo a solução coloidal que foi deixada em agitação S / N. Agita-se a solução durante 25 min. </li><li> Descarte os resíduos que tenham sido, eventualmente gerados de acordo com os protocolos de segurança e protecção do ambiente de laboratório. </li></ol> 2. Gel película de deposição de Si (100) Substratos <ol><li> Preparação dos substratos <ol><li> Cortar Si lajes de cerca de 2 cm por 5 cm em cada um de 2 polegadas do tipo p (100) da bolacha de silício com uma espessura de 200 micra por clivagem da bolacha numa direcção paralela ou perpendicular ao plano da bolacha usando uma ponta de diamante ou um objeto pérfuro-cortante. Execute esta etapa em anúncioVance, por exemplo, um dia antes da deposição das películas de gel. </li><li> Pouco antes da deposição dos géis, limpar os substratos com etanol e deixar secar ou usar um fluxo de azoto ou ar comprimido para acelerar a secagem. Execute esta etapa enquanto aguarda a conclusão da etapa 1.3. </li></ol></li><li> Brasão dos filmes. A fim de se obter uma estrutura homogénea macroporos executar este passo sob condições de humidade relativa entre 20% e 55%, à TA. <ol><li> Estabelecer uma sequência de revestimento por imersão. Seleccionar as posições iniciais e finais, tendo em conta o comprimento real da laje de Si e o nível da solução no recipiente de forma a que a laje é, pelo menos, 2 cm acima do nível da solução na posição de partida e 1 cm acima do fundo do proveta no final da imersão. Defina ambas as velocidades de imersão e retirada a 150 mm / min. Defina o tempo de imersão (o tempo na posição final) para zero. </li><li> Após a conclusão do passo 1.3 Colocar o copo com a assimlução em uma posição bem centrada abaixo da laje Si pendurado no braço dip-coater. </li><li> Fix uma extremidade da laje de Si ao braço DIP-revestidor com o grampo, assegurando a laje é o mais perpendicular possível em relação à horizontal. </li><li> Execute a sequência de revestimento por imersão e desencaixe a laje Si a partir do braço dip-coater. Repita os passos 2.2.3 e 2.2.4 com lajes Si adicionais para produzir mais filmes, tomando cuidado para não estender esses preparativos para além de 1 h, para assegurar que a estabilidade da solução não seja comprometida. </li></ol></li><li> Descarte as soluções que foram gerados, eventualmente, de acordo com os protocolos de segurança e protecção do ambiente de laboratório. </li></ol> 3. Gel de Cinema de cristalização por tratamento térmico <ol><li> O tratamento térmico das películas de gel de Si (100). <ol><li> Programa de um forno para executar o seguinte tratamento térmico em atmosfera de ar: aquecimento do IR para 1000 ° C a 3 ° C / min, mantendo a 1.000 °; C durante 5 horas e arrefecimento até à TA, a 3 ° C / min. </li><li> Colocar os substratos de Si revestidas por imersão em uma barquinha de alumina, introduzi-la no forno e executar o tratamento térmico. </li></ol></li><li> A limpeza dos filmes cristalizados. <ol><li> Mergulhar os filmes cristalizados durante 3 horas em HNO 3 concentrado a fim de remover as acumulações de Sr 2+ que foram expulsas para a superfície da película durante a cristalização e em seguida enxaguar as películas primeiro com água desionizada e, em seguida, com etanol. </li></ol></li></ol>

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Os autores não têm nada a revelar.

O método apresentado é uma abordagem de baixo para cima para produzir filmes de quartzo macroporosas sobre Si. Comparado com o método padrão de produção de filmes de quartzo, uma tecnologia de ponta para baixo com base no corte e polimento de grandes cristais hidrotermicamente cultivadas, o método descrito no protocolo permite a obtenção de películas muito finas, com espessuras entre 150 e 450 nm, que podem ser controlados com o taxa de retirada. Todos os dados experimentais sobre o controlo do quartzo filmes ...

Quando um material piezoeléctrico como quartzo-α é submetido a uma tensão de polarização que é submetido a uma deformação mecânica. Se este material é poroso, estas variações de volume podem conduzir a expansão dos poros ou contracção, a criação de um sistema sensível semelhante ao que pode ser observada em vivo organelas biológicas. 1 deformável poroso α-quartzo foi produzido utilizando microfabrico, 2, mas tais técnicas não podem ainda produzir estruturas de poros de 3-D, e são diâmetros de poros da ordem de centenas de nanómetros. A cristalização de sílica amorfa estruturada tem sido dificultada pela nucleação não homogêneo causado por altas energias de superfície e deformação arquitetônica devido ao engrossamento e de fusão. Além disso, uma vez que todas as formas de sílica são construídos sobre SiO 4 redes de tetraedros extremamente estáveis, as energias livres de formação de sílica amorfa, α-quartzo e outros SiO 2 polimorfos são quase iguais em uma ampla gama de temperaturas, fazendog difícil produzir α-quartzo, como um único polimorfo da cristalização de um gel de sílica amorfa. 3 Outro aspecto que torna mais difícil a cristalização controlada de sílica amorfa estruturado é que o quartzo apresenta uma velocidade de nucleação relativamente lento, mas uma taxa de crescimento extremamente rápido, relataram entre 10-94 nm / seg. 4,5 nucleação lenta associada a um crescimento rápido tende a gerar cristais muito maiores do que a estrutura original é nanoporoso, assim, a morfologia original é perdido. Metais alcalinos, tais como Na + e Li +, têm sido utilizados para cristalizar α-quartzo, frequentemente em combinação com o tratamento hidrotérmico. 5,6 Além disso, um Ti 4+ / Ca 2+ combinação foi utilizado para cristalizar partículas esféricas de sílica em quartzo por uma via química suave utilizando alcóxidos de silício. 7. No entanto, a cristalização controlada de uma película de sílica amorfa estruturado em quartzo manteve-se um desafio. SiO2 sob pressão ambiente e a temperaturas relativamente baixas. 8,9 epitaxia, surge a partir do desfasamento favorável entre α-quartzo e o substrato&gt; silício &lt;100, produção de filmes finos orientados piezoeléctricos. A evaporação induzida por auto-montagem para a produção de filmes de sílica mesoporosa tem sido usado desde 1999. 10 Esta técnica tem sido estudado e aplicado a um grande número de agentes modeladores sob várias condições para produzir poros de tamanhos variáveis ​​e mesofases. Verificou-se que as mudanças no tamanho mesoporo subnanometric pode ter um efeito dramático sobre a difusão de soluto através de sistemas porosos 11, validando esta grande atenção à estrutura de poros. Além disso, a acessibilidade ao sistema de silica de poro interna pode ser obtido através do controlo da fase micelar do molde 12. Aqui, a via de síntese Tchapéu permite controlo sem precedentes sobre o tamanho de poro e da espessura das camadas de sílica amorfa usando uma separação de fases é demonstrada romance. 13 Estas películas são infiltradas com (ii) sais de estrôncio e cristalizou-se para ácido a-quartzo a 1000 ° C sob ar à pressão ambiente. O tamanho de poro retainable usando este processo de cristalização é determinado, e o efeito da espessura da parede e espessura da película é estudada. Finalmente piezeletrecidade e a deformabilidade do sistema de poros, são estudados.

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			<td height="21" style="height:21px;width:180px;">Dip coater</td>
			<td style="width:281px;">Nadetech&#160;</td>
			<td style="width:173px;">ND-DC 11/150&#160;</td>
			<td style="width:80px;"></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:180px;">Furnace</td>
			<td style="width:281px;">Nabertherm&#160;</td>
			<td>R 50/250/12</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:180px;">Atomic Force Microscope</td>
			<td style="width:281px;">Agilent&#160;</td>
			<td>5500 LS</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:180px;">Materials and Reagents&#160;</td>
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			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:180px;">Silicon wafers</td>
			<td style="width:281px;">SHE Europe Ltd.</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:180px;">SrCl2&#183;6H2O</td>
			<td style="width:281px;">Aldrich</td>
			<td>13909</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:180px;">CTAB</td>
			<td style="width:281px;">Aldrich</td>
			<td>H5582</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:180px;">Ethanol Absolute&#160;</td>
			<td style="width:281px;">Aldrich</td>
			<td>161086</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:180px;">HCl 35% solution</td>
			<td style="width:281px;">PanReac</td>
			<td>721019</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:180px;">TEOS</td>
			<td style="width:281px;">Aldrich</td>
			<td>131903</td>
			<td></td>
		</tr>
	</tbody>
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preparation of macroporous epitaxial quartz films on silicon by chemical solution deposition

This work describes the detailed protocol for preparing piezoelectric macroporous epitaxial quartz films on silicon(100) substrates. This is a three-step process based on the preparation of a sol in a one-pot synthesis which is followed by the deposition of a gel film on Si(100) substrates by evaporation induced self-assembly using the dip-coating technique and ends with a thermal treatment of the material to induce the gel crystallization and the growth of the quartz film. The formation of a silica gel is based on the reaction of a tetraethyl orthosilicate and water, catalyzed by HCl, in ethanol. However, the solution contains two additional components that are essential for preparing mesoporous epitaxial quartz films from these silica gels dip-coated on Si. Alkaline earth ions, like Sr2+ act as glass melting agents that facilitate the crystallization of silica and in combination with cetyl trimethylammonium bromide (CTAB) amphiphilic template form a phase separation responsible of the macroporosity of the films. The good matching between the quartz and silicon cell parameters is also essential in the stabilization of quartz over other SiO2 polymorphs and is at the origin of the epitaxial growth.

O progresso da síntese material foi controlado através da monitorização diferentes aspectos. Depois de o processo de imersão-revestimento pode-se observar o aspecto dos filmes, o eventual aparecimento de estruturas de difracção no local reflectida de um laser verde e a Microscopia Electrónica de Varrimento (SEM) imagens no modo de electrões com retroespalhamento (Figura 1A-B). Após o processo de cristalização é importante para gravar Atómica microscopia de ...

Watch this Scientific Journal Video about Preparation of Macroporous Epitaxial Quartz Films on Silicon by Chemical Solution Deposition at JoVE.com

Preparation of Macroporous Epitaxial Quartz Films on Silicon by Chemical Solution Deposition

A protocol is presented for the preparation of piezoelectric macroporous epitaxial films of quartz on silicon by solution chemistry using dip-coating and thermal treatments in air.

Preparação de macroporosas Epitaxial quartzo Filmes sobre Silicon Chemical Solution Deposition por

This work describes the detailed protocol for preparing piezoelectric macroporous epitaxial quartz films on silicon(100) substrates. This is a three-step ...

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9.2K visualizações.  CNRS-École Centrale de Lyon. A protocol is presented for the preparation of piezoelectric macroporous epitaxial films of quartz on silicon by solution chemistry using dip-coating and thermal treatments in air. 

Vídeo: Preparation of Macroporous Epitaxial Quartz Films on Silicon by Chemical Solution Deposition

Preparation of Hydrophobic Metal-Organic Frameworks via Plasma Enhanced Chemical Vapor Deposition of Perfluoroalkanes for the Removal of Ammonia

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high surface area microporous materials, such as metal-organic frameworks (MOFs), unique challenges present themselves for PECVD treatments. Herein the protocol for development of a MOF that was previously unstable to humid conditions is presented. The protocol describes the synthesis of Cu-BTC (also known as HKUST-1), the treatment of Cu-BTC with PECVD of perfluoroalkanes, the aging of materials under humid conditions, and the subsequent ammonia microbreakthrough experiments on milligram quantities of microporous materials. Cu-BTC has an extremely high surface area (~1,800 m2/g) when compared to most materials or surfaces that have been previously treated by PECVD methods. Parameters such as chamber pressure and treatment time are extremely important to ensure the perfluoroalkane plasma penetrates to and reacts with the inner MOF surfaces. Furthermore, the protocol for ammonia microbreakthrough experiments set forth here can be utilized for a variety of test gases and microporous materials.

Herein the procedures for plasma enhanced chemical vapor deposition of perfluoroalkanes on microporous materials such as metal-organic frameworks to enhance their stability and hydrophobicity are described. Furthermore, breakthrough testing of milligram quantities of samples is described in detail.

Preparação de hidrofóbicos Metal-Organic Frameworks via Plasma aprimorado Chemical Vapor Deposition de perfluoroalcanos para a remoção de amônia

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high ...

Química

Atomically Defined Templates for Epitaxial Growth of Complex Oxide Thin Films

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain such surfaces are described. The first approach is the preparation of single terminated perovskite SrTiO3 (001) and DyScO3 (110) substrates. Wet etching was used to selectively remove one of the two possible surface terminations, while an annealing step was used to increase the smoothness of the surface. The resulting single terminated surfaces allow for the heteroepitaxial growth of perovskite oxide thin films with high crystalline quality and well-defined interfaces between substrate and film. In the second approach, seed layers for epitaxial film growth on arbitrary substrates were created by Langmuir-Blodgett (LB) deposition of nanosheets. As model system Ca2Nb3O10- nanosheets were used, prepared by delamination of their layered parent compound HCa2Nb3O10. A key advantage of creating seed layers with nanosheets is that relatively expensive and size-limited single crystalline substrates can be replaced by virtually any substrate material.

Various procedures are outlined to prepare atomically defined templates for epitaxial growth of complex oxide thin films. Chemical treatments of single crystalline SrTiO3 (001) and DyScO3 (110) substrates were performed to obtain atomically smooth, single terminated surfaces. Ca2 Nb3 O10- nanosheets were used to create atomically defined templates on arbitrary substrates.

Templates atomicamente definidos para crescimento epitaxial do Complexo Óxido Filmes Finos

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain ...

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 ...

Preparation of Highly Porous Coordination Polymer Coatings on Macroporous Polymer Monoliths for Enhanced Enrichment of Phosphopeptides

We describe a protocol for the preparation of hybrid materials based on highly porous coordination polymer coatings on the internal surface of macroporous polymer monoliths. The developed approach is based on the preparation of a macroporous polymer containing carboxylic acid functional groups and the subsequent step-by-step solution-based controlled growth of a layer of a porous coordination polymer on the surface of the pores of the polymer monolith. The prepared metal-organic polymer hybrid has a high specific micropore surface area. The amount of iron(III) sites is enhanced through metal-organic coordination on the surface of the pores of the functional polymer support. The increase of metal sites is related to the number of iterations of the coating process.
The developed preparation scheme is easily adapted to a capillary column format. The functional porous polymer is prepared as a self-contained single-block porous monolith within the capillary, yielding a flow-through separation device with excellent flow permeability and modest back-pressure. The metal-organic polymer hybrid column showed excellent performance for the enrichment of phosphopeptides from digested proteins and their subsequent detection using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The presented experimental protocol is highly versatile, and can be easily implemented to different organic polymer supports and coatings with a plethora of porous coordination polymers and metal-organic frameworks for multiple purification and/or separation applications.

A procedure for the preparation of porous hybrid separation media composed of a macroporous polymer monolith internally coated by a high surface area microporous coordination polymer is presented.

Preparação de altamente poroso Coordenação Polymer Revestimentos em macroporosas Polymer Monólitos para o enriquecimento avançado de Fosfopeptídeos

We describe a protocol for the preparation of hybrid materials based on highly porous coordination polymer coatings on the internal surface of macroporous ...

Preparation of Mica and Silicon Substrates for DNA Origami Analysis and Experimentation

The designed nature and controlled, one-pot synthesis of DNA origami provides exciting opportunities in many fields, particularly nanoelectronics. Many of these applications require interaction with and adhesion of DNA nanostructures to a substrate. Due to its atomically flat and easily cleaned nature, mica has been the substrate of choice for DNA origami experiments. However, the practical applications of mica are relatively limited compared to those of semiconductor substrates. For this reason, a straightforward, stable, and repeatable process for DNA origami adhesion on derivatized silicon oxide is presented here. To promote the adhesion of DNA nanostructures to silicon oxide surface, a self-assembled monolayer of 3-aminopropyltriethoxysilane (APTES) is deposited from an aqueous solution that is compatible with many photoresists. The substrate must be cleaned of all organic and metal contaminants using Radio Corporation of America (RCA) cleaning processes and the native oxide layer must be etched to ensure a flat, functionalizable surface. Cleanrooms are equipped with facilities for silicon cleaning, however many components of DNA origami buffers and solutions are often not allowed in them due to contamination concerns. This manuscript describes the set-up and protocol for in-lab, small-scale silicon cleaning for researchers who do not have access to a cleanroom or would like to incorporate processes that could cause contamination of a cleanroom CMOS clean bench. Additionally, variables for regulating coverage are discussed and how to recognize and avoid common sample preparation problems is described.

Reproducible cleaning processes for substrates used in DNA origami research are described, including bench-top RCA cleaning and derivatization of silicon oxide. Protocols for surface preparation, DNA origami deposition, drying parameters, and simple experimental set-ups are illustrated.

Preparação de Mica e silício substratos para análise do DNA Origami e Experimentação

The designed nature and controlled, one-pot synthesis of DNA origami provides exciting opportunities in many fields, particularly nanoelectronics. Many of ...

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 ...

Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films

Organo-lead halide perovskites have recently attracted great interest for potential applications in thin-film photovoltaics and optoelectronics. Herein, we present a protocol for the fabrication of this material via the low-pressure vapor assisted solution process (LP-VASP) method, which yields ~19% power conversion efficiency in planar heterojunction perovskite solar cells. First, we report the synthesis of methylammonium iodide (CH3NH3I) and methylammonium bromide (CH3NH3Br) from methylamine and the corresponding halide acid (HI or HBr). Then, we describe the fabrication of pinhole-free, continuous methylammonium-lead halide perovskite (CH3NH3PbX3 with X = I, Br, Cl and their mixture) films with the LP-VASP. This process is based on two steps: i) spin-coating of a homogenous layer of lead halide precursor onto a substrate, and ii) conversion of this layer to CH3NH3PbI3-xBrx by exposing the substrate to vapors of a mixture of CH3NH3I and CH3NH3Br at reduced pressure and 120 &#176;C. Through slow diffusion of the methylammonium halide vapor into the lead halide precursor, we achieve slow and controlled growth of a continuous, pinhole-free perovskite film. The LP-VASP allows synthetic access to the full halide composition space in CH3NH3PbI3-xBrx with 0&#160;&#8804; x&#160;&#8804; 3. Depending on the composition of the vapor phase, the bandgap can be tuned between 1.6 eV&#160;&#8804; Eg&#160;&#8804; 2.3 eV. In addition, by varying the composition of the halide precursor and of the vapor phase, we can also obtain CH3NH3PbI3-xClx. Films obtained from the LP-VASP are reproducible, phase pure as confirmed by X-ray diffraction measurements, and show high photoluminescence quantum yield. The process does not require the use of a glovebox.

Here, we present a protocol for the synthesis of CH3NH3I and CH3NH3Br precursors and the subsequent formation of pinhole-free, continuous CH3NH3PbI3-xBrx thin films for the application in high efficiency solar cells and other optoelectronic devices.

Processo de solução assistida por Vapor de baixa pressão para banda sintonizável Gap Pinhole-free Methylammonium chumbo haleto perovskita filmes

Organo-lead halide perovskites have recently attracted great interest for potential applications in thin-film photovoltaics and optoelectronics. Herein, ...

Aerosol-assisted Chemical Vapor Deposition of Metal Oxide Structures: Zinc Oxide Rods

Whilst columnar zinc oxide (ZnO) structures in the form of rods or wires have been synthesized previously by different liquid- or vapor-phase routes, their high cost production and/or incompatibility with microfabrication technologies, due to the use of pre-deposited catalyst-seeds and/or high processing temperatures exceeding 900 &#176;C, represent a drawback for a widespread use of these methods. Here, however, we report the synthesis of ZnO rods via a non-catalyzed vapor-solid mechanism enabled by using an aerosol-assisted chemical vapor deposition (CVD) method at 400 &#176;C with zinc chloride (ZnCl2) as the precursor and ethanol as the carrier solvent. This method provides both single-step formation of ZnO rods and the possibility of their direct integration with various substrate types, including silicon, silicon-based micromachined platforms, quartz, or high heat resistant polymers. This potentially facilitates the use of this method at a large-scale, due to its compatibility with state-of-the-art microfabrication processes for device manufacture. This report also describes the properties of these structures (e.g., morphology, crystalline phase, optical band gap, chemical composition, electrical resistance) and validates its gas sensing functionality towards carbon monoxide.

Columnar zinc oxide structures in the form of rods are synthesized via aerosol-assisted chemical vapor deposition without the use of pre-deposited catalyst-seed particles. This method is scalable and compatible with various substrates based on either silicon, quartz or polymers.

Aerossol-assistida de deposição de Vapor químico de estruturas de óxido de Metal: hastes de óxido de zinco

Whilst columnar zinc oxide (ZnO) structures in the form of rods or wires have been synthesized previously by different liquid- or vapor-phase routes, ...

Reactive Vapor Deposition of Conjugated Polymer Films on Arbitrary Substrates

We demonstrate a method of conformally coating conjugated polymers on arbitrary substrates using a custom-designed, low-pressure reaction chamber. Conductive polymers, poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-propylenedioxythiophene) (PProDOT), and a semiconducting polymer, poly(thieno[3,2-b]thiophene) (PTT), were deposited on unconventional highly-disordered and textured substrates with high surface areas, such as paper, towels and fabrics. This reported deposition chamber is an improvement of previous vapor reactors because our system can accommodate both volatile and nonvolatile monomers, such as 3,4-propylenedioxythiophene and thieno[3,2-b]thiophene. Utilization of both solid and liquid oxidants are also demonstrated. One limitation of this method is that it lacks sophisticated in situ thickness monitors. Polymer coatings made by the commonly used solution-based coating methods, such as spin-coating and surface grafting, are often not uniform or susceptible to mechanical degradation. This reported vapor phase deposition method overcomes those drawbacks and is a strong alternative to common solution-based coating methods. Notably, polymer films coated by the reported method are uniform and conformal on rough surfaces, even at a micrometer scale. This feature allows for future application of vapor deposited polymers in electronics devices on flexible and highly textured substrates.

This paper presents a protocol for reactive vapor deposition of poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), and poly(thieno[3,2-b]thiophene) films on glass slides and rough substrates, such as textiles and paper.

Depósito de Vapor reativa dos filmes de polímeros conjugados em substratos arbitrários

We demonstrate a method of conformally coating conjugated polymers on arbitrary substrates using a custom-designed, low-pressure reaction chamber. ...

Deposition of Porous Sorbents on Fabric Supports

A microwave deposition technique for silanes, previously described for production of oleophobic fabrics, is adapted to provide a fabric support material that can be subsequently treated by dip coating. Dip coating with a sol preparation provides a supported porous layer on the fabric. In this case, the porous layer is a porphyrin functionalized sorbent system based on a powdered material that has been demonstrated previously for the capture and conversion of phosgene. A representative coating is applied to cotton fabric at a loading level of 10 mg/g. This coating has minimal impact on water vapor transport through the fabric (93% of the support fabric rate) while significantly reducing transport of 2-chloroethyl ethyl sulfide (CEES) through the material (7% of support fabric rate). The described approaches are suitable for use with other fabrics providing amine and hydroxyl groups for modification and can be used in combination with other sol preparations to produce varying functionality.

This report details a microwave-initiated approach for deposition of porphyrin functionalized porous organosilicate sorbents on a cotton fabric and demonstrates reduction in 2-chloroethyl ethyl sulfide (CEES) transport through the fabric resulting from this treatment.

Deposição de Sorbents porosa sobre suportes de tela

A microwave deposition technique for silanes, previously described for production of oleophobic fabrics, is adapted to provide a fabric support material ...