Research Projects

The exfoliation of graphene has led to the search for new materials with an intrinsic electronic energy gap, such as MoS₂, MoO₃, and h-BN. Resistive switching devices consist of a capacitive structure with switching material sandwiched between metal electrodes. 2-D CaF₂ has been proposed as a good insulating material for 2-D transistor fabrication, showing an on/off ratio up to 10⁷ compatible with traditional Si-based transistors. The project aims to address the fundamental failure mechanism of the insulator in CaF₂ and CaF₂/MoS₂ based nanocomposites. Active metals like Ag and Cu will be used as electrodes to test the resistive switching mechanism. The study will focus on metal ion migration (cation) devices and the formation of oxygen or nitrogen ion vacancies (anion) devices. A nanocomposite will be prepared using an optimized synthesis route with varying concentrations of MoS₂. The switching characteristics will be compared to a simple double-layer structure of CaF₂-MoS₂. Initial experiments confirm the switching of the nanocomposite device at low voltages (1-2V). A pinched hysteresis loop combined with simultaneous memory and logic operation is essential for an energy-efficient device. Non-volatile memory devices fabricated using the CaF₂/MoS2 nanocomposite can become the foundation for reliable neuromorphic devices. This project addresses fundamental questions such as understanding the chemical composition of the filament, the role of electric field and thermal energy, filament morphology, conduction mechanism, and switching dynamics.