Organic-inorganic hybrid thin films based in HfO2 nanoparticles as dielectric for flexible electronics

In this work the synthesis and characterization of an organic-inorganic hybrid composite film based on hafnium oxide (HfO2) and polyvinylpyrrolidone (PVP) with dielectric properties is presented. These films were prepared using the sol-gel process adjusting the chemical composition to tailor the material properties, such as the dielectric and the optical band gap. The HfO2 was obtained by the hydrolysis of hafnium chloride (HfCl4) under catalysis of ethanol and deionized water, later the PVP was subsequently added to complete the hydrolysis. Finally the films were dried at 150 degrees C. The structural characterization of the hybrid material showed a hafnium nanoparticle size around 100 nm into the polymer matrix. The chemical structure and the high purity of the hybrid material were corroborated by X-ray photoelectron spectroscopy measurements, which showed the bounding of HfO2-PVP. The electrical characterization demonstrated that the nanostructured materials with hafnium nanoparticles improve the dielectric constant in the films with values around k = 18.5. The optical band gap, E-o, was obtained from 4 to 5.7 eV. These characteristics in our hybrid material are very promising for flexible electronics applications with the advantage of its low temperature, thermal stability, and low cost process of deposition.