Photoelectrical performances of semiconductor-based devices having CoFe and CoFeNi magnetic interlayers

This study was designed to examine the photoelectric device performances of cobalt-iron (CoFe) and cobalt-iron-nickel (CoFeNi) materials with good magnetic properties, specifically to investigate the effect of the Ni element on the electrical properties. In this context, Al/CoFe/p-Si and Al/CoFeNi/p-Si devices were produced by coating both materials between the semiconductor and the metal using the radio frequency (RF) sputtering method. First of all, to investigate the structural properties of the coated films, the content analysis was carried out by x-ray diffraction (XRD) analysis. To determine the photoelectrical properties of the produced devices, current-voltage and transient photocurrent measurements were performed and analyzed under different light intensities. While the ideality factor (barrier height) values of the devices produced using CoFe and CoFeNi materials were found to be 11.45 (0.487 eV) and 9.86 (0.513 eV), respectively, in the dark, they were obtained as 13.29 (0.446 eV) and 11.02 (0.484 eV) under 100 mW cm-2 illumination. It was determined that both devices are sensitive to light, with the sensitivity of the device with the CoFeNi interlayer being much higher. In addition, photocapacitance and photoconductivity measurements were carried out to examine the photocapacitor performance of the devices. As a result of the investigations, both current-voltage, photocurrent, and photo-capacitance/conductivity measurements showed that the device with the CoFeNi interface layer showed better performance than the device with the CoFe interface. Therefore, it has been determined that the Ni element has a positive effect on electrical properties. The results obtained show that the prepared materials and produced devices can be used in photovoltaic applications.