Research Projects

This research proposal focuses on investigating and harnessing ferroelectric properties in two-dimensional (2D) van der Waals (vdW) materials, specifically transition metal dichalcogenides (TMDs), for quantum optoelectronic applications. The project addresses a critical gap in understanding the relationship between ferroelectric order and excitonic/optoelectronic properties in these materials while developing practical solutions for controlled ferroelectric switching. The research builds upon recent discoveries in interfacial ferroelectricity in parallelly stacked TMD layers, where unprecedented polarization retention occurs even under high carrier densities. Unlike traditional ferroelectrics that lose polarization at nanoscale dimensions, these materials maintain polarization even at atomic layers and exhibit enhanced polarization strength with additional layers. In addition, they are stable at room temperature. This unique characteristic makes them promising candidates for next-generation electronic and optoelectronic devices, particularly for applications like in-memory computation for neuromorphic circuitry. The project is structured around four main work packages: (WP1) Sample preparation and initial characterization using techniques like Raman spectroscopy, atomic force microscopy (AFM), and Kelvin probe force microscopy (KPFM) (WP2) Investigation of excitonic properties through micro-spectroscopy (WP3) Discerning correspondence between multi-state ferroelectricity and its excitonic response. Subsequently, elucidate the mechanisms and limiting factors behind ferroelectric switching through domain wall motion (WP4) Development of ferroelectric arrays to address topological and stochastic limitations in switching processes The methodology involves mechanical exfoliation from bulk crystals and chemical vapor deposition growth for sample preparation. A key innovation is the fabrication of arrays of isolated ferroelectric islands using electron beam lithography and plasma etching, which helps overcome topological constraints in switching and overcome stochastic variability through ensemble averaging. The research will utilize state-of-the-art facilities, including a custom-built micro-spectroscopy setup with spatial filtering capabilities. This setup will enable diffraction-limited high-resolution spectroscopic measurements crucial for such a material system. The project leverages existing collaborations with national and international institutions for material sourcing and characterization. The proposal seeks to establish the PI institution's first dedicated research program on 2D van der Waals quantum materials, integrating local probes and far-field micro-spectroscopic techniques. This will lay the groundwork for future advancements, including time-resolved measurements and exploration of other material systems.