Mechanochemical Synthesis of YFeO₃ Nanoparticles: Optical and Electrical Properties of Thin Films

Nanoparticles (NPs) of orthorhombic YFeO₃, has been successfully synthesized via an uncomplicated mechanochemical method from yttrium and iron chloride salts in a basic medium. The YFeO₃ NPs were characterized by micro-Raman and Fourier-transform infrared spectroscopy. Their crystalline structure and average diameter of 30 nm was determined from X-ray powder diffraction pattern and by transmission electron microscopy images. Thin films (TF) of these NPs in polystyrene were prepared by spin coating in order to study their electrical and optical properties, as well as to verify their possible application in the manufacture of optoelectronic devices. UV–visible diffuse reflectance was performed for YFeO₃ NPs and for YFeO₃ TF and optical band gaps of 2.38 and 3.7 eV, respectively, were estimated from optical absorption measurements. The electrical conductivity of the YFeO₃ TF was evaluated in a glass/ITO/YFeO₃TF/Ag device. At low voltages, electric current in the forward direction was found to obey an ohmic I–V relationship; at higher voltages, the behavior of the film in the device is defined by a Space Charge Limited Current model and, at around 1 V, current saturation. These results suggest the possibility of using YFeO₃ TF in the production of dielectric layers in electronic or optoelectronic devices.