Estudio de las propiedades estructurales y luminiscentes de películas de TiO2 impurificadas con Eu3+ sintetizadas por la técnica de rocío pirolítico ultrasónico

En este trabajo se reportan los cambios estructurales y luminiscentes al variar la temperatura de sustrato (Ts) y el porcentaje de impurificarte en películas de TiO2. Los resultados muestran que es posible obtener películas con buenas propiedades

Películas delgadas de TiO2 impurificadas con Eu3+ por rocío pirolítico ultrasónico

En este trabajo se reportan los cambios estructurales y luminiscentes presentes al variar la temperatura de sustrato (Ts) y porcentajes de material impurificarte en películas delgadas de TiO2. Los resultados revelan que mediante la técnica de rocío pirolítico (SP) es posible obtener buenas propiedades estructurales y luminiscentes

Crecimiento de películas delgadas de TiO2 impurificadas con tierras raras por la técnica de rocío pirolítico asistida por campo eléctrico

En este trabajo se reportan los cambios estructurales y luminiscentes que se presentan al variar la temperatura de depósito (Td) y los porcentajes de material impurificarte o activador en películas delgadas de TiO2. Los resultados demuestran que mediante la técnica de rocío pirolítico (SP) es posible obtener películas delgadas con buenas propiedades estructurales y luminiscentes

STRUCTURAL AND OPTICAL PROPERTIES OF ZnO:Al FILMS PREPARED BY ULTRASONIC SPRAY PYROLYSIS

Thin films of non-stoichiometric and doped metallic oxides of ZnO, In2O3 ,SnO2, CdO, In2O3:Sn (ITO),SnO2:F, In2O3:F, ZnO:Al etc. have attracted a large interest because of their high electrical conductivity and optical transmittance in the visible region of solar spectrum making them suitable for their application in different kinds of opto-electronic devices. Because of the fact that a high conductivity and a high transmittance in the visible region can be achieved simultaneously, they are used as transparent electrodes in thin film solar cells. Among these materials, zinc oxide was felt important compared with tin oxide and indium oxide due to its stability in hydrogen plasma, which is of unique importance in amorphous and microcrystalline silicon areas. The spray technique is one of the most commonly used technique for preparation of transparent and conducting oxides owing to its simplicity, safety, non-vacuum system of deposition and hence inexpensive method for large area coatings. By characterizing the deposition parameters especially the spraying temperature, flow rate and the amount of doping concentration, it is possible to deposit Al-doped ZnO (AZO) thin films having suitable values of sheet resistance and transmittance. Films of zinc oxide doped with Al (ZnO:Al) are prepared using the spray pyrolysis technique. In this work the effect of doping Al on the physical properties of ZnO:Al is studied. Polycrystalline ZnO:Al films with the different Al concentration ([Al]/[Zn] in the starting solution was varied from 0 to 0.2 wt.%) were prepared. We varied the substrate temperature and deposition time. These films were confirmed to show the high crystallinity by X-ray diffraction technique. The optical transmittance was varied form 90% to 40% in visible range depending of the film thickness

Structural and luminescent properties of europium doped TiO2 thick films synthesized by the ultrasonic spray pyrolysis

The structural and luminescent properties of trivalent europium-doped titanium dioxide films synthesized by the ultrasonic spray pyrolysis technique at several substrate temperatures are reported. These films are nanocrystalline and present a mixture of tetragonal (anatase and rutile) crystal structures of the titania as determined by x-ray diffraction. The rutile crystal structure became predominant as the substrate temperature during deposition was increased. Under UV and electron beam excitation, these coatings showed strong luminescence due to f–f transitions and the dominant transition was the hypersensitive 5D0 →7F2 red emission of Eu3+. The photo- and cathodoluminescence characteristics of these films were studied as a function of growth parameters such as substrate temperature and europium concentration. Excitation with a wavelength of 396 nm resulted in photoluminescent emission peaks located at 557, 580, 592, 615, 652 and 703 nm, associated with the electronic transitions of the Eu3+ ion. The photoluminescence (PL) intensity as a whole is observed to decrease as the deposition temperature is increased. Also, with increasing doping concentration, a quenching of the PL is observed. The chemical composition and surface morphology characteristics of the films are also reported