Heterojunction formation is the key to adjusting the electronic and optoelectronic properties of various semiconductor devices. There have been various reports on the formation and importance of semiconducting heterojunction devices based on metal oxides. Titanium dioxide (TiO₂) is one of the metal oxides that has many unique properties. TiO₂'s importance is due to its physical and chemical properties such as large band gap, large permittivity, stability, and low leakage current density. In this context, we present the electrical properties of the metal-insulator-semiconductor (MIS) type-TiO₂-based Schottky barrier diode (SBD) in the study. To create a thin layer of TiO₂ on p-type silicon (p-type Si) patterned partially by the laser-induced periodic surface structure (LIPSS) technique, an atomic layer deposition (ALD) technique was used in the study. For comparison, the current-voltage (I-V) characteristics of the TiO₂-based laser-patterned (LP) and nonlaser-patterned (non-LP) diodes were measured at 300 K and in the dark at ±5 V. Classical thermionic emission (TE) theory and Cheung functions were used to investigate the critical diode parameters of the diodes, including ideality factor (n), series resistance (R_s), and barrier height (Φ_b). The n values were obtained as 4.10 and 3.68 from the TE method and Cheung functions for the LP diode, respectively. The Φ_b values were found as 0.68 and 0.69 eV from the TE method and Cheung functions, respectively. According to experimental results, the laser patterning resulted in an increase in the Φ_b values and a decrease in the n values. After laser patterning, it was observed that the device worked effectively, and the ideality factor and barrier height values were improved. This study provides insight into the fabrication and electrical properties of TiO₂-based heterojunction devices.

In our study, how the thin metal oxide (aluminium oxide, Al2O3) thin film placed between the metal and the semiconductor on the diode characteristics will affect was investigated. The Al2O3 thin film was suitable for its grown on p-type silicon substrate by atomic layer deposition (ALD) technique. A diode structure with an oxide interlayer was fabricated. To investigate the electrical parameters of the fabricated Schottky diode, measurements of current-voltage (I-V) were carried out at room temperature and in the 5 V voltage range. Using the I-V measurements, diode parameters such as the barrier height (Φb), the ideality factor (n), and the current density (I0) were evaluated using the Thermionic Emission (TE) method. Using the TE method, the approximate values of Φb, n, and Io parameters were calculated as 0.77 eV, 5.43, and 2.43E-09 A respectively. According to calculations, the developed Schottky diode is a rectifier diode and has been determined to have photodiode properties.

This study focuses on investigating the electrical behaviour of Metal-Insulator-Semiconductor (MIS) type Schottky barrier diodes based on titanium oxide (TiO2). An MIS-type Al/TiO2/p-Si Schottky diode structure was fabricated by depositing a TiO2 metal oxide thin film as an interlayer on p-type silicon using the technique of Radio Frequency Magnetron Sputtering at room temperature. The electrical performance of this fabricated structure was evaluated through the measurements of current-voltage (I-V) conducted in a dark environment at ±5 V and room temperature. These measurements enabled the determination of key Schottky diode parameters, including barrier height (Φb), saturation current (Io), and ideality factor (n), using both the Thermionic Emission (TE) method and the Cheung method. Utilizing the TE method, approximate values for Φb, n, and Io parameters were calculated as 0.59 eV, 4.07, and 2.78E-06 A, respectively. Meanwhile, employing Cheung’s method yielded approximate values of Φb and n parameters as 0.39 eV (H(I) vs I) and 4.39 (dV/dln(I) vs I), respectively. The analysis indicates that the developed Schottky diode functions as a rectifier diode, demonstrating typical diode characteristics. Furthermore, a comparison of numerous devices reported in the literature was conducted based on TiO2 preparation methods against the parameters of the TiO2/p-Si host device.

A nanocomposite material comprising palladium nanoparticles (PdNPs) doped with polyethyleneimine (PEI)-functionalized nitrogen-doped graphene quantum dots (PEI N-GQDs) was synthesized and employed as an interlayer in an Ag/PdNPs/PEI N-GQDs/p-Si heterojunction configuration. The PdNPs/PEI N-GQDs nanocomposite was prepared through an aqueous reaction between PEI-functionalized N-GQDs and Pd(NO ₂ ) ₂ ·H ₂ O and characterized using FTIR, UV–Vis, TEM, XPS, and PL spectroscopy. The PL spectrum exhibited a broad emission centered at 580 nm (2.14 eV) with a near-infrared tail, indicating defect-assisted recombination and confirming the semiconducting nature of the nanocomposite. The Ag/PdNPs/PEI N-GQDs/p-Si diode displayed a rectification ratio of approximately 1.64 × 10 ² at ± 4 V, with barrier heights of 0.87, 0.76, and 0.68 eV obtained from thermionic-emission (TE), Cheung, and Norde methods, respectively. Energy band alignment analysis revealed that the rectifying behavior originates from the Ag/nanocomposite interface, forming a Schottky-type barrier, while a type-II staggered junction is established at the nanocomposite/p-Si interface, facilitating hole transport. These findings demonstrate the potential of PdNPs/PEI N-GQDs as an effective interlayer material for carbon-based nanoelectronic and optoelectronic devices.