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In this report, a doped semiconducting ink consisting of a blended poly [2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) with aluminium-tris (8-hydroxychinolin) (Alq3) and diluted in toluene is formulated. The intentional doping with the electron transport nanoparticle Alq3 results in an additional band gap state of the hole transport MEH-PPV polymer and reduction of the switch on voltage of the organic LED display. Doping is probed at room temperature with photoluminescence spectroscopy. Photoluminescence results revealed that as the Alq3 content increases in blends, characteristic peaks of intensities of MEH-PPV are broadened and reduced. In addition, the emission for Alq3 concentrations between 30% and 60% are featured by a band at 565 nm (2.19 eV) for the lower concentration and consistently blue shifted to 530 nm (2.33 eV) for the higher concentration. This new band at 565 nm (2.19 eV) neither belongs to pure MEH-PPV nor to Alq3 and evidences charge transfer from the lowest unoccupied molecular orbital of the Alq3 to the highest occupied molecular orbital of the MEH-PPV.

RESUMENEn este trabajo se depositaron recubrimientos de carburo de niobio sobre aceros AISI M2, H13 y D2, utilizando la técnica de deposición por difusión termorreactiva. Los carburos se obtuvieron usando baños de sales compuestos por bórax fundido, ferroniobio, ferrovanadio y aluminio a una temperatura de 1.020 °C durante 4 horas. La presencia de los recubrimientos fue observada por microscopia electrónica de barrido. Las fases fueron determinadas usando difracción de rayos X, y se utilizó microdureza para determinar la dureza. El comportamiento electroquímico fue estudiado mediante curvas de polarización potenciodinámica para determinar la densidad de corriente de corrosión, y espectroscopia de impedancia electroquímica para determinar la resistencia a la polarización. Los resultados fueron comparados con las propiedades del sustrato sin recubrimiento y en general se observó mayor dureza y mejor resistencia a la corrosión en los recubrimientos producidos.Palabras clave: Difusión, carburos de niobio, impedancia, aceros para herramientas, corrosión. ABSTRACTIn this work, niobium carbide coatings were deposited on AISI M2, H13, and D2 tool steels by thermoreactive deposition/diffusion. The carbides were obtained using salt baths composed of molten borax, aluminum, and ferroniobium at a temperature of 1020 °C for 4 hours. The coatings were observed via scanning electron microscopy. The phases were determined using X-ray diffraction, and Vickers indentation was used to determine the hardness. The electrochemical behavior was studied via potentiodynamic polarization curves to determine the rate of corrosion and electrochemical impedance spectroscopy was used to determine the resistance to polarization. The results were compared with the properties of the substrate without a coating, and in general, greater hardness and better corrosion resistance were observed with the coatings.