Journal of Materials Science: Materials in Electronics, cilt.37, sa.12, 2026 (SCI-Expanded, Scopus)
This study investigated the current–voltage (I–V) characteristics of an Au/TiO2/p-GaAs MIS diode under dark conditions and under illumination intensities ranging from 20 to 120 mW/cm2 at room temperature. X-ray diffraction (XRD) analysis was employed to characterize the crystal structure of the TiO2 film deposited on the GaAs substrate. Key electrical parameters—including the ideality factor (n), saturation current (I0), barrier height (ΦB), and series resistance (Rs)—were extracted using both the thermionic emission model and the Norde method, with the two approaches yielding consistent results. Upon illumination, the MIS diode exhibits pronounced photoconductivity, manifested by a significant enhancement in the reverse-bias current, while the forward-bias current shows minimal variation. Forward-bias I–V measurements were further used to evaluate the density of interface states (Nss). Charge-transport analysis reveals a transition from ohmic conduction to space-charge-limited conduction (SCLC) under forward bias. Besides, the current-conduction mechanism of the MIS diode was analyzed under forward bias. Overall, the results confirm that the produced MIS diode is sensitive to light and can be used in optoelectronic applications.