Research Projects

Quantum-confined materials, particularly those combining two-dimensional (2D) transition metal dichalcogenides (TMDs) like SnS₂ and WS₂ with zero-dimensional (0D) lead-free perovskite quantum dots (QDs), are gaining significant attention for their potential in optoelectronic and neuromorphic devices. These materials offer a unique combination of electronic, optical, and excitonic properties that are advantageous for artificial synapses, which are essential for neuromorphic computing. Neuromorphic devices aim to mimic the brain’s neural architecture, enabling more efficient computation compared to traditional systems, and these 2D-0D hybrid structures are especially promising for their role in low-power, high-speed, and flexible computing technologies. 2D TMDs like SnS₂ and WS₂ exhibit outstanding electronic properties, including high electron mobility, strong light-matter interaction, and stability, which are ideal for optoelectronic applications. WS₂, for instance, is a direct bandgap semiconductor in its monolayer form, making it highly effective for devices like photodetectors and light-emitting diodes (LEDs). SnS₂, on the other hand, complements WS₂ by providing higher electron mobility and stability, which helps optimize charge transport in heterostructures. Together, these materials form heterostructures with engineered band alignment, enhancing charge carrier separation and efficiency in optoelectronic devices. This combination of materials is key to enabling advanced functionalities in artificial synapses, which are crucial for emulating the brain’s information-processing capabilities. Incorporating lead-free perovskite quantum dots, such as Cs₃Bi₂Br₉ or CsSnBr₃, into these 2D TMD structures offers additional advantages. These QDs are non-toxic alternatives to lead-based perovskites and exhibit size-dependent tunability of optical properties due to quantum confinement effects. Their strong light absorption, fast carrier dynamics, and high photoluminescence make them suitable for applications where the control of light and charge is necessary, such as in neuromorphic systems. In particular, the ability to fine-tune emission wavelengths and modulate conductivity in response to light stimuli is essential for the development of optoelectronic synapses that replicate the plasticity of biological synapses. Neuromorphic devices based on 2D-0D materials use these optoelectronic properties to emulate synaptic plasticity, a critical function for learning and memory in artificial neural networks. In this setup, optical stimulation of the quantum dots can induce charge transfer to the TMD layer, altering its electrical properties in a way that mimics synaptic behavior. This modulation of charge transfer and exciton dynamics enables multi-level switching behavior, which is vital for information storage and processing in neuromorphic computing. By leveraging the optoelectronic interplay between SnS₂, WS₂, and perovskite QDs, researchers can achieve low-power, high-speed, and highly scalable neuromorphic devices. Moreover, these hybrid materials enable flexible, wearable neuromorphic devices, opening up new applications in smart sensors, adaptive learning systems, and robotics. The combination of mechanical flexibility, efficient charge transport, and tunable optical properties makes this 2D-0D material system highly adaptable to various forms of computing and sensing technologies. In summary, the integration of SnS₂-WS₂ TMDs with lead-free perovskite QDs creates a promising platform for the development of next-generation optoelectronic neuromorphic devices. The hybrid system's synergistic properties make it ideal for low-power, high-efficiency computing, paving the way for advancements in artificial intelligence and sensor technologies.