ResumoFilmes de óxido de estanho com flúor, depositados sobre substratos transparentes, foram preparados a partir de uma solução contendo uma mistura de NH 4 F e SnCl 2 . Uma resistência cerâmica, inserida em um forno, foi usada como fonte de calor. A deposição foi feita por meio da técnica pulverização pirolítica, com vácuo sendo gerado no bico de pulverização. A caracterização das amostras foi feita com auxílio de microscopia eletrônica de varredura, espectroscopia UV-vis, resistência elétrica e difração de raios-X. Os resultados indicam a aplicabilidade do material para a aérea fotovoltaica. Palavras-chave:Óxido de estanho com flúor: Pulverização pirolítica: Vácuo. AbstRActFluoride-doped tin oxide films on glass substrate were prepared from NH 4 F-doped SnCl 2 precursor by spray pyrolysis with ceramic heater as heat source, which was inserted inside the reactor and created a vacuum within nozzle. The films were characterized by scanning electron microscopy, UV-Vis spectroscopy, measurement of electrical resistance and X-ray diffraction. The results showed that the fluoride-doped tin oxide films demonstrate potential as materials for photovoltaic applications.

A eletrodeposição tem sido empregada para a obtenção de materiais semicondutores; todavia, ainda não estão bem esclarecidos os mecanismos envolvidos neste processo. Neste sentido, este trabalho apresenta a investigação deste processo, evidenciando a caracterização do CdTe eletrodepositado sobre substrato platina em solução ácida. A deposição ocorre a partir de 0,0 V, em relação ao eletrodo Ag/AgCl,KCl sat , com etapas de controle ativado e de difusão. Os filmes finos de CdTe foram eletrodepositados sobre o substrato de platina a temperatura ambiente (~24°C) a partir de uma solução ácida. A influência do potencial aplicado foi investigada utilizando técnicas de caracterização de superfície, como a difração de raios X e Microscopia eletrônica de varredura. A caracterização elétrica foi realizada por medidas de capacitância (Mott-Schottky). Os filmes finos de CdTe apresentaram pico de maior intensidade no plano (220), demostrando ter um crescimento preferencial para esse plano. Os filmes apresentam uma morfologia granular influenciado pelo potencial de deposição e uma condutividade característica de um semicondutor tipo n. Palavras-chave:Filme finos de CdTe, Eletrodeposição, Platina. ABSTRACTThe electrodeposition has been used for obtaining semiconductor materials; however, remain unclear the mechanisms involved in this process. Thus, this paper presents the research of this process, showing the characterization of electrodeposited CdTe on platinum substrate in acid solution. The deposition occurs from 0.0 V relative to the electrode Ag/AgCl KCl sat with step activated control and diffusion. The thin film of CdTe was electrodeposited on the platinum substrate at room temperature (~ 24 ° C) from an acidic solution. The influence of the applied potential was investigated using surface characterization techniques such as Xray diffraction analyses and scanning electron microscopy. The electrical properties of the films were performed capacitance measurements (Mott-Schottky plot). The thin CdTe films presented the prominent (220) planes, showing have a preferential growth in that plane. The films show a granular morphology influenced by deposition potential and property of an n-type semiconductor.

Solar energy is one of the most important sources of renewable energy today. The production of electric energy is based on silicon cells, which are expensive and difficult to produce and therefore, New preparation methods, materials or approaches are needed. This work aims to deposit Tin oxide doped with fluorine, prepared by sol-gel, on a glass substrate using the spray pyrolysis technique. F-SnO2 (FTO) solution was synthesized by sol-gel method, employing NH4F and SnCl2 precursors in an ethanol solution. Before the formation of the gel, the solution was sprayed using a pistol aerographic, On a substrate at approximately 600oC. This process was repeated 50 times, and after that, the sample was cooled until room temperature inside the furnace. The obtained samples (substrates for the PV cell) present a resistance between 10 and 30 Ω. The energy dispersive x-ray (EDS) was used to confirm the presence of fluorine in the SnO2 network.

This paper presents the study of the addition of the polyaniline polymer (PANI), at the junction of the cadmium telluride and cadmium sulfide (CdTe/CdS) layers in order to improve the contact between the layers, to decrease the air gap that limit the conversion photovoltaic. The morphology of CdS, CdTe and polyaniline (PANI) were characterized with multiple techniques including scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and optical absorption. The Metrohm Autolab LED Driver Kit system was used for data collection, and it was possible to obtain the current and voltage parameters of the cells. The inclusion of PANI thin film in CdS/CdTe hybrid solar cells increases the energy conversion efficiency from 0.0075% to 0.15%, this gives a 20-fold increase in efficiency.