Electrical performance of Schottky diodes based on macroporous silicon and titanium oxide extracted from Malagasy ilmenite

Abstract

• Investigation of Ag/TiO 2 /MPS/Si Schottky diodes using TiO 2 extracted from Malagasy ilmenite. • Structural analysis confirms the presence of TiO 2 on the MPS surface with anatase, rutile, and brookite phases. • Electrical characterization via I–V and C–V measurements shows that immersion time in TiO 2 solution strongly affects diode performance. • The I–V characteristics are modeled using Cheung’s equations to extract diode parameters. • A significant dielectric tunability is found, varying between 41 and 67% depending on the applied frequency. This work presents the synthesis and electrical characterization of Schottky diodes based on Ag/TiO 2 /macroporous silicon (MPS), where titanium dioxide is extracted from Malagasy ilmenite. The MPS structures were fabricated using a silver-assisted chemical etching method, and TiO 2 was deposited by immersion in an acid-based solution for various durations. Structural analyses via FTIR, Raman spectroscopy, and XRD confirmed the successful deposition of TiO 2 on MPS surface, revealing the coexistence of anatase, rutile, and brookite phases for titanium dioxide. Electrical performance was evaluated through current–voltage (I-V) and capacitance–voltage (C-V) measurements. The diode characteristics such as ideality factor, series resistance, and barrier height were found to be strongly dependent on immersion time. Optimal diode behavior, including enhanced rectification and reduced series resistance, was observed for immersion times between 5 and 15 min. Frequency-dependent C–V and conductance–voltage (G–V) measurements indicated significant interfacial effects and charge trapping phenomena. These findings highlight the potential of TiO 2 -modified MPS structures for advanced electronic and optoelectronic applications.