• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Desenvolvimento de um compósito contendo polímero condutor (PEDOT:PSS) e material ORMOSIL (GPTMS) com aplicação na fabricação de dispositivos eletroluminescentes / Development of a composite containing conducting polymer (PEDOT:PSS) and ORMOSIL material (GPTMS) with application in the manufacture of electroluminescent devices

Colucci, Renan [UNESP] 27 June 2016 (has links)
Submitted by Renan Colucci null (37412942840) on 2016-07-12T19:19:53Z No. of bitstreams: 1 dissertação_RENAN_versãofinal.pdf: 3242692 bytes, checksum: c7bf17a6e3f70f7b97cb6c8ecfa1e065 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-07-15T16:29:02Z (GMT) No. of bitstreams: 1 colucci_r_me_rcla.pdf: 3242692 bytes, checksum: c7bf17a6e3f70f7b97cb6c8ecfa1e065 (MD5) / Made available in DSpace on 2016-07-15T16:29:02Z (GMT). No. of bitstreams: 1 colucci_r_me_rcla.pdf: 3242692 bytes, checksum: c7bf17a6e3f70f7b97cb6c8ecfa1e065 (MD5) Previous issue date: 2016-06-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Atualmente é possível fabricar dispositivos eletroluminescentes (EL) utilizando como material ativo uma dispersão de um pó eletroluminescente inorgânico em uma matriz polimérica condutora. Entretanto, esses materiais são quimicamente instáveis, o que impede a deposição de alguns materiais solúveis sobre eles, como por exemplo, eletrodos de tinta prata. Para solucionar este problema, desenvolvemos uma matriz condutora e quimicamente estável formada pelo polímero condutor poli(3,4-etileno dioxitiofeno):poliestireno sulfonado (PEDOT:PSS) e pelo material sílica-orgânico 3-glicidoxipropil trimetilsilano (GPTMS). Foram produzidos compósitos de PEDOT:PSS/GPTMS com diversas concentrações de PEDOT:PSS, com os quais foram produzidos filmes uniformes, insolúveis e com condutividade elétrica entre 2 S/cm e 400 S/cm. A dependência da condutividade elétrica destes materiais em função da temperatura e da concentração de PEDOT:PSS foi descrita pelo modelo de transporte de cargas variable range hopping (VRH-3D). Adicionando-se o material eletroluminescente (EL) inorgânico silicato de zinco dopado com manganês (Zn2SiO4:Mn) à matriz condutora de PEDOT:PSS/GPTMS foi obtido um compósito para a produção de dispositivos EL. Depositando-se este compósito EL sobre substratos de vidro contendo eletrodos transparentes de óxido de estanho e índio, foram obtidos dispositivos EL com tensão de operação de 30 V e eficiência luminosa de 1,3 cd/A. Além disso, a transmitância óptica e a resistência de folha de filmes do compósito condutor (PEDOT:PSS/GPTMS) foram avaliadas, demonstrando que este material apresenta propriedades compatíveis com a aplicação como eletrodo transparente. Por fim, foram produzidos dispositivos EL utilizando o compósito condutor PEDOT:PSS/GPTMS como eletrodos e o compósito EL PEDOT:PSS/GPTMS/ Zn2SiO4:Mn como material ativo. Com este experimento, foi demonstrada a possibilidade de fabricar dispositivos EL por rota líquida, onde o compósito PEDOT:PSS/GPTMS foi utilizado tanto para a fabricação dos eletrodos como para a produção do material ativo do dispositivo. / It is possible to fabricate light-emitting (LE) devices with LE composites as active material. These light-emitting composites are produced with a LE inorganic powder dispersed into a conducting polymer matrix. However, these composites are chemically unstable, limiting the deposition of soluble materials over it. To overcome this problem we developed a high-stability conductive matrix comprising the conductive polymer poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and the organic-silicate 3-glycidyloxypropyl)trimethoxysilane (GPTMS). Composites PEDOT:PSS/GPTMS with diverse weight concentrations of PEDOT:PSS were produced and used to fabricate high-stability films with electrical conductivity from 2 S/cm up to 400 S/cm. The charge transport in these conductive composites were studied as function of the temperature, as well as of the PEDOT:PSS concentration, and described by the 3D variable range hopping model. A light-emitting composite was produced adding to this conductive composite the inorganic electroluminescent powder Mn-doped zinc silicate (Zn2SiO4:Mn). Light-emitting devices, with turn-on voltage of 30 V and luminous efficacy of 1.3 cd/A, were produced with a coating of the developed LE composite done over glass substrates containing indium tin oxide transparent electrodes. Additionally, the optical transmittance and sheet resistance of films produced with the conductive composite PEDOT:PSS/GPTMS were evaluated showing that this material is suitable to fabricate transparent electrodes. Finally, were produced light-emitting devices employing the conductive composite PEDOT:PSS/GPTMS as electrodes and the light-emitting composite PEDOT:PSS/GPTMS/ Zn2SiO4:Mn as active material. This experiment has shown the fabrication of solution-processed light-emitting devices using the composite PEDOT:PSS/GPTMS as transparent electrode and as component of the active material.
2

Conception et étude d'antennes actives optiquement transparentes : de la VHF jusqu'au millimétrique / Conception and study of optically transparent and active antennas : from VHF to millimeter wave

Martin, Alexis 23 October 2017 (has links)
Avec le développement de l’internet des objets et l’augmentation des applications sans fil, les antennes sont de plus en plus présentes au quotidien. Cependant, l’implantation de ces antennes est un challenge tant d’un point de vue technologique (intégration des antennes dans les dispositifs), que psychologique (acceptabilité des antennes par le grand public). Dans ce contexte, le développement d’antennes optiquement transparentes permet non seulement leur implantation sur de nouvelles surfaces (vitrages d’immeubles, écrans de smartphones ...), mais promeut aussi leur acceptabilité par le grand public grâce à leur faible impact visuel. Ce travail présente la conception, la fabrication et la caractérisation d’antennes actives optiquement transparentes. Le matériau transparent et conducteur utilisé est un maillage métallique à pas micrométrique développé spécifiquement, alliant conductivité électrique et transparence optique élevées. Dans ce cadre, un premier prototype d’antenne transparente et miniature en bande FM utilisant un transistor MESFET de dimensions sub-millimétriques a été réalisé. Des antennes agiles en fréquence en bande X (~10 GHz) couplées, soit à une diode varicap localisée (agilité ~10%), soit à un matériau ferroélectrique (agilité ~2%), ont été développées et étudiées. Une antenne passive transparente a été conçue en bande V (~60 GHz). Enfin, une transition optique (1540 nm) / hyperfréquence (1,4 GHz) a été réalisée et caractérisée, basée sur la transmission optique d’un faisceau laser au travers du matériau constitutif de l’antenne. Pour l’ensemble des prototypes réalisés, une transparence optique supérieure à 80% dans le domaine du visible associée à une résistance par carré inférieure à 0,1 ohm/sq ont été utilisées. / Within the development of the Internet of Things (IoT) and the increase of the wireless communications, antennas are even more present on everyday life. However, antenna implementation is a real challenge, from a technological point of view (antenna integration into the devices) and from a psychological point of view (acceptability by the general public). Within this framework, the development of optically transparent antennas on new surfaces (glass windows, smartphone screens . . . ) is of great interest to improve the network coverage and to assist the general public in acceptability thanks to the low visual impact of such printed antennas. The present work deals with the design, the fabrication and the characterization of optically transparent and active antennas. The transparent and conducting material used is a micrometric mesh metal film specifically developed, associating high electrical conductivity and high optical transparency. A first optically transparent and miniature FM antenna based on a MESFET transistor with micrometric size has been designed and fabricated. Frequency agile antennas operating in X-band (~10 GHz), based on a beam-lead varactor (agility ~10%) and on a ferroelectric material agility ~2%), have been developed and characterized. An optically transparent and passive antenna has been studied in V-band (~60 GHz). At last, optics (1540 nm) / microwave (1.4 GHz) transition has been performed based on the transmission of a laser beam through the transparent antenna. For all prototypes, an optical transparency level higher than 80% coupled with a sheet resistance value lower than 0.1 ohm/sq have been used.

Page generated in 0.107 seconds