Investigation of the photodiode properties of schottky diodes with Al/NiCo₂O₄/n-Si/Al configuration
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi University, Fen Bilimleri Enstitüsü, -, Turkey
Approval Date: 2024
Thesis Language: Turkish
Student: Yusuf ATMACA
Supervisor: Şükrü Çavdar
Open Archive Collection: AVESIS Open Access Collection
Abstract:
In this study, NiCo2O4 (nickel cobaltite) thin film structure was coated on Schottky diode and different substrates to characterise its electrical and optical properties. NiCo2O4 thin film structure on Co3O4 (cobalt oxide) seed layer was formed using spin coating technique on n type Si, glass and FTO (fluorine doped tin oxide) substrates. Surface analysis of the NiCo2O4 thin film structure was performed using scanning electron microscopy (SEM). Detailed structural properties of NiCo2O4 thin film were investigated by energy dispersive spectroscopy (EDS) analysis. The crystal structure of NiCo2O4 thin film was also investigated by x-ray diffraction (XRD) analysis. The NiCo2O4 thin film structure on glass and FTO surfaces was analysed by ultraviolet and visible light (UV-Vis) spectroscopy and optical transmittance and absorption analysis. Al/NiCo2O4/n-Si/Al Schottky diode structure was formed and its electro-optical and electrical properties were investigated at different illumination intensities at visible light wavelengths. The ideality factor (n), barrier height (Φb) and saturation current (I0) values of the materials were calculated using current-voltage (I-V) graphs. It was determined that the photocurrent in reverse polarisation increased as the illumination intensity increased, the samples were photosensitive and showed photodiode properties. Finally, capacitance-voltage (C-V) and conductivity-voltage (G-V) properties were analysed to investigate the capacitive properties. When all these data were evaluated, it was seen that NiCo2O4 is a suitable material that can be used as a photodiode in optoelectronic applications in different fields with these properties.
Key Words : NiCo2O4, n-Si, ideality factor, barrier height, Schottky diode, photodiode