Research

Our research vision is to advance the scientific foundation that underlies the current and potential future of materials and quantum sciences.  Our research directions focus to advance fundamental understanding and the experimental knowledge for the development of new scalable nanostructured materials and novel 2D materials for emerging nanoscale applications, and quantum sources for telecom quantum network technologies deeply impacting our lives as we are moving towards the fourth industrial revolution. 

On-Demand CMOS-Compatible Fabrication of Self-Aligned Nanostructures  

The field of semiconductor nanowires (NWs) has become one of the most active research areas. However, progress in this field has been hindered, due to the difficulty in controlling defect density, and deterministic assembly of NW arrays, parameters important for mass production of electronic nanodevices and the creation of practical nanoscale-based systems. Our group is focused on developing CMOS-compatible fabrication strategies for nanostructured materials, for example silicon carbide (SiC) and silicon oxycarbide NW arrays. These strategies enable the development of scalable ultrathin nanostructures, with reduced defect density, which can serve as an experimental platform to investigate NW-based emerging technologies, such as nanowire sensing, nanophotonics, and quantum photonics.

Related research work:

On-demand CMOS-Compatible Fabrication of Ultrathin Self-Aligned SiC Nanowire Arrays

Time-resolved analysis of the white photoluminescence from chemically synthesized SiCxOy thin films and nanowires

Strong visible light emission from silicon-oxycarbide nanowire arrays prepared by electron beam lithography and reactive ion etching

Scalable Nanophotonic Structures for Long-Distance Quantum Communications 

Non-classical (single-photon) light sources emitting in the near-infrared region of the electromagnetic spectrum, where signal transmission losses in optical fibers are small, are essential for the development of long-distance optical quantum networks. Our research work has been aimed to advance fundamental understanding and the experimental knowledge to develop  critical optical properties of rare earth ion dopants, coupled and enabled by new nanophotonic structures, which provide high integration capabilities with silicon nanophotonics. We have introduced a new class of CMOS-compatible silicon carbide nanowire-based photonic crystal structures. These nanophotonic structures enable strong coupling and on-demand placement of rare-earth erbium (Er3+) ions in the nanowires.  The technologically important low-loss Er3+-induced 1540 nm emission can thus be controlled and substantially enhanced by these photonic nanostructures. Benefits from the fundamental understanding of erbium emission in such scalable nanophotonic structures can expedite advances towards room temperature telecom single-photon sources.

Related research work:

Polarization-dependent photoluminescence properties of fab-compatible nanowire-based nanophotonic structures

Engineered Telecom Emission and Controlled Positioning of Er3+ Enabled by SiC Nanophotonic Structures

On-demand CMOS-Compatible Fabrication of Ultrathin Self-Aligned SiC Nanowire Arrays

Strong photoluminescence enhancement of silicon oxycarbide through defect engineering

Pseudo-1D Materials and Polarization-Dependent Nanophotonic Devices 

Emerging 2D gallium chalcogenides, such as gallium telluride (GaTe), are promising layered semiconductors that can serve as vital building blocks towards the implementation of nanodevices in the fields of nanoelectronics, optoelectronics, and quantum photonics. By leveraging our novel chemical passivation methods for environmental-stable GaTe flakes, our focus has been to study the anisotropy in the optical properties of GaTe nanomaterials and nanodevices. The anisotropy is caused by the 1D-like nature of the GaTe layer, as the layer comprises of Ga-Ga chains extending along the b-axis crystal direction. The identification of the b-axis in such anisotropic materials is imperative for the fabrication of polarization-dependent devices based on the generation and detection of polarized light, such as polarized photodetectors and light sources. 

Related research work:

Wavelength-Dependent Anisotropic Optical Properties in Layered GaTe for Polarization-Sensitive Applications

Study of Oxidation and Polarization-Dependent Optical Properties of Environmentally Stable Layered GaTe Using a Novel Passivation Approach

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