Polaritons (nano-light) are hybrid nano-scaled light-matter modes that involve collective oscillations of polarization charges in the matter, they are associated with different constituents and can interact to produce unique optical effects by design. Studying the fundamental properties of polaritons, understanding light-matter interactions, and developing new methods to engineer polaritons are of great importance in the field of nanophotonics. We have developed some novel methods for tailoring light-phonon interactions (phonon polaritons) and nano-light propagations in van der Waals materials. These novel methods include twisting (Left panel), microstructuring, heterostructuring, and isotope heterostructuring (Right panel) which resulted in the successful control of light-matter interactions and nano-scaled light propagation such as wavelength, wavefront, reflection, dispersions, and phase velocity in the materials. 

2D materials exhibit unique electronic and optical properties, offering a versatile platform for creating heterostructures with tunable characteristics. This makes 2D materials-based devices promising candidates for integration into next-generation electronic and optoelectronic technologies. We used various 2D materials as building blocks to design nano-electronic and optoelectronics devices such as non-volatile programmable p-n junctions (Left panel) and Schottky junction memory (Right panel). The research provides a foundation for their use in logic rectifiers and optoelectronics with a variety of applications, including logic circuits, transistors, memory, photovoltaics, logic optoelectronics, and light emission.

Developing novel optoelectronic and photonic devices is essential for advancing technologies in a wide range of applications, including sensing, communication, and energy systems. We have demonstrated several innovative devices, such as a tandem gasochromic Pd-WO₃/graphene/Si optoelectronic device for room-temperature high-performance hydrogen sensing (Left panel),  as well as in photonic device design, where, by broadening the photonic band gap of a one-dimensional photonic crystal in the terahertz frequency range, we can significantly improve the performance of terahertz filters and modulators (Right panel).