Impact of yttrium on structural, optical and electrical behavior of CuO thin film prepared by JN spray pyrolysis technique for diode application

The thin films of CuO with yttrium as a dopant at 1, 3, and 5wt% are prepared using a simple and economic JNS spray pyrolysis technique at the optimized substrate temperature of 600 °C. The impact of yttrium doping on the structural, optical, and electrical properties of CuO thin films has been investigated. The structural properties of synthesized films are analyzed using X-ray diffraction (XRD) studies, which confirmed that all the films are polycrystalline with a monoclinic structure. Scanning electron microscopy was analyzed to study the changes that occurred in the morphology of the sample with the concentration of yttrium doped. The optical characteristics of the films are investigated using a UV–Vis absorption spectrophotometer. Y 3+ ion causes the fall of absorption in the visible region. The optical bandgap of the pure and yttrium-doped CuO thin films are calculated from the Tauc’s plot of their absorption spectrum. The higher the concentration of the yttrium, larger the bandgap value indeed. The variation in the electrical behavior of the prepared films with the yttrium concentration has been investigated using a Keithley electrometer two-probe setup. The average conductivity of the films increases as the yttrium content increases. The p-YCuO/n-si diodes with 1%, 3%, and 5% yttrium doped on CuO are fabricated and their ideality factors (n) and potential barrier values (Φ) are calculated using the JV method. The presence of Y 3+ ions makes the rectification behavior of the diodes better.