This study investigates the negative differential resistance (NDR) phenomenon in cobalt-doped tin dioxide (SnO2:Co) memristors fabricated on p-type silicon substrates. Using ultrasonic spray pyrolysis (USP), crystalline SnO2:Co thin films were deposited on p-Si substrates with a thin native SiO2 layer. The resulting memristor devices exhibit reproducible bipolar resistive switching between high-resistance (HRS) and low-resistance states (LRS). Key findings include the observation of a distinct NDR region in the current-voltage (I-V) characteristics, specifically in the positive voltage range from approximately +3V to +4V. Within this NDR region, current decreases despite increasing voltage, a characteristic hallmark of this effect. This behavior is attributed to the charge trapping and redistribution within the Co:SnO2 material. The consistent and reproducible nature of the observed NDR effect suggests the potential of SnO2:Co memristors for applications in advanced memory and switching technologies. This work contributes to the understanding of resistive switching mechanisms in Co-doped SnO2 thin films, which are promising materials for next-generation memory devices.

This study presents the fabrication and resistive switching (RS) performance of bilayer SnO2/ZnO thin films deposited via ultrasonic spray pyrolysis on p-type silicon substrates. The heterostructures were post-annealed at 450°C to enhance crystallinity and interfacial contact. Electrical characterization using I–V measurements revealed clear bipolar RS behavior without the need for an initial forming process. The devices exhibited a stable high resistance state (HRS) and low resistance state (LRS) across multiple cycles, with an ON/OFF ratio exceeding 10². The switching mechanism is attributed to the formation and rupture of conductive filaments likely induced by oxygen vacancies at the SnO₂/ZnO interface. Bandgap estimation using Tauc plots showed values of approximately 3.17 eV and 3.41 eV for ZnO and SnO2, respectively. These findings confirm the potential of SnO2/ZnO heterojunctions as efficient materials for next-generation non-volatile memory applications.

Gallium oxide (Ga₂O₃) is an ultrawide bandgap semiconductor (~4.8–5.0 eV) that has recently gained considerable attention for next-generation nanoelectronic and memory devices owing to its superior breakdown field, chemical durability, and thermal robustness. In this study, Ga₂O₃ thin films were fabricated through a sol–gel spin-coating route and subsequently annealed at 1000 °C. X-ray diffraction revealed the structural evolution from an amorphous state to the stable monoclinic β-Ga₂O₃ phase after annealing. Electrical measurements exhibited reproducible bipolar resistive switching with an ON/OFF resistance ratio exceeding 102 and relatively low set/reset voltages. The observed switching is interpreted within the framework of conductive filament formation and rupture, predominantly governed by oxygen vacancy dynamics. The combination of low-cost synthesis, scalable processing, and robust memristive performance highlights sol–gel derived Ga₂O₃ thin films as strong contenders for future resistive random-access memory (RRAM) architectures and neuromorphic computing technologies.

The architecture of perovskite solar cells (PSCs) and the interfaces between charge transport layers and the perovskite layer are crucial to performance. T

Based on scientific sources presenting modern semiconductor device fabrication technologies and growth methods, the influence of external factors on ZnO samples was evaluated through various approaches. In this work, ZnO thin films were grown on Si substrates using the ultrasonic spray pyrolysis (USP) method. The physical characteristics of the obtained samples, including the optical bandgap energy and in-situ laser Raman spectroscopy measurements, were investigated. The primary objective of this study was to synthesize ZnO thin films with precise nanometric thicknesses on silicon (Si) substrates and to investigate the influence of substrate temperature, precursor composition, and evaporation rate. Using Ellipsometry, XRD, and SEM, we characterized the film thickness, crystal lattice structure, and morphological evolution during growth.

Influence of the sulfur doping on the structural, optical, electrical and magnetic properties of ZnMnO thin films fabricated using the ultrasonic spray pyrolysis technique was investigated. Our study reveals that increasing sulfur content leads to a noticeable shift in the band gap energy towards the red spectrum, an indicator of altered electronic states and potential for enhanced spintronic functionalities. The strong reduction in the band gap for the sulfur doped ZnMnO alloys is the result of the upward shift of the valence-band edge. As a result, the room temperature bandgap of ZnMnO1-xSx alloys can be tuned from 3.2 eV to 2.97 eV for x ≤ 0.2. The observed large bowing in the composition dependence of the energy bandgap arises from the anticrossing interactions between the valence-band of ZnO and the localized sulfur level above the ZnMnO valence-band maximum. The doping process significantly modifies the ferromagnetic properties, with an observed increase in Curie temperature correlating with higher sulfur concentrations. These changes are attributed to the increased free holes concentration, which facilitates a more robust exchange interaction between the magnetic ions. Additionally, the structural assessments via scanning electron microscopy confirm the uniform integration of sulfur into the ZnMnO matrix, resulting in distinct nanocrystalline formations. This study contributes to the understanding of doping mechanisms in semiconductor materials, especially for highly mismatched alloys, where the anions are partially substituted with isovalent atoms of considerably different size and/or electronegativity, offering insights into the tunability of their magnetic and electronic properties for potential future applications in spintronic devices.