Propriedades físico-quimica de membranas de Ecovio® eletrofiadas e incorporadas por ultrassom com liga de índio-selênio

Abstract

The development of technology has brought various changes and advantages to companies, both in production, in the sale and delivery of products. Accompanying this development comes the growing need for electricity, mainly from renewable sources. In this context, we highlight the conversion of solar energy into electricity, or photovoltaic energy. Still in this context, scientists have been working on the development of flexible semiconductor devices whose applications range from foldable cell phone screens to wearable photovoltaic cells. To accompany this development, nanostructured materials, and techniques that produce these materials are gaining space in the scientific world. The greater understanding of the properties of these materials has increased the number of publications on the technique of electrospinning that produces fibers, with diameters in nanoscale. In this work, fibers were produced by the electrospinning technique from an Ecovio® polymer solution. An indium-selenium (10%-90%) chalcogenide semiconductor alloy was incorporated into these fibers. In order to study the retention of the alloy by the fiber, it was treated with an alkaline solution of sodium hydroxide (NaOH) at the concentrations of 0.8%, 1.2% and 1.6%. The semiconductor alloy was dispersed in isopropyl alcohol and incorporated into the fiber with the aid of ultrasound, remaining for 10, 20 and 30 minutes at minimum power. The fibers with the incorporation of the alloy were investigated by thermal analysis (Differential Scanning Calorimetry - DSC and Thermogravimetry - TGA), X-ray diffraction (XRD), infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and photoacoustic spectroscopy (EFA). The findings include i) increased crystallinity of pure fiber (without any intervention) when subjected to ultrasound; ii) decrease in thermal stability of the fibers when subjected to alkaline treatment; iii) the semiconductor alloy was incorporated into the polymer fibers,evidenced by the results of the analyzes described above, but there seems to be no relationship to either the concentration of the alkaline treatment or the time of application of the ultrasound to the fibers. Photoacoustic spectroscopy allowed the determination of gap energy, also used as further evidence that the alloy was incorporated into the polymer.