Ponente
Descripción
With the continuous technological development and its respective energy demand, it has been necessary to develop alternative sources of energy that are friendly to the environment. Based on solar energy, as the most abundant, safe, and clean source, ferroelectric materials are studied for application in photovoltaic cells. The K0.5Na0.5NbO3 (KNN) system is one of the lead-free materials that features excellent piezoelectric and electromechanical properties, high density, and high Curie temperature [1]. In this work, the synthesis route of the K0.5Na0.5NbO3 (KNN) system was studied by sol-gel with an excess of 5 and 10% of excess K, due to its easy volatilization. The solutions obtained were deposited by spin coating in multilayers and a calcination and sintering treatment was given at 400°C and 550°C, respectively. By XRD, a single phase was obtained, which was more crystalline as K increased. By EDS, the loss of K during the synthesis processes or heat treatment was confirmed. SEM analysis gave us thicknesses around 100nm for films of 12 layers. Using the ferroelectric curves, combined behaviors of a linear dielectric with the presence of conductivity were obtained. For the optical characterization, I-V curves showed a photosensitive response comparing darkness, visible and ultraviolet light. Sol-gel is highlighted as a viable route for the fabrication of KNN thin films without the use of toxic solvents. The route synthesis followed is a starting point to make some modifications to improve the band gap.
