The goals of this project are to synthesize atomically thin two-dimensional (2D) semiconducting layers, which possess novel properties often unavailable in their bulk counterparts, and incorporate them onto devices for novel photonic applications. Once demonstrated, these active and nonlinear photonic devices using 2D materials can potentially create a new paradigm of optoelectronics and may lead to numerous optical information and quantum information related applications. A multidisciplinary team from four academic institutions (Rensselaer Polytechnic Institute, Pennsylvania State University, Virginia Polytechnic Institute and State University, and Washington University in St. Louis) is formed to investigate key research areas from 2D material synthesis, condensed matter theory, and optical engineering. This project also includes a comprehensive education and outreach plan at all levels, from encouraging underprivileged K-12 students into the exciting field of material sciences and optical engineering all the way up to faculty mentoring.
This project aims to predict, synthesize, characterize, and engineer semiconducting transition metal dichalcogenides (STMD) such as molybdenum and tungsten disulfides and diselenides, and utilize them to develop a new class of potentially transformative active and nonlinear photonic devices. A key challenge to develop high-quality 2D STMD materials is the control of these materials with predetermined thickness (number of layers), stacking and composition, and to tailor their optical properties for specific photonics applications. The synthesis strategy of this project is based on chemical vapor deposition (CVD), which has been proved suitable for synthesizing large-area (cm) 2D crystals of STMD, and for controlling the growth, clustering, doping, alloying and stacking of different STMD. The research team aims to establish a comprehensive first-principles framework for modeling the doping, alloying and stacking of a few layered STMD. The team develops more realistic approaches for the band structure (GW approximation) and excitonic behaviors by solving the Bethe-Salpeter equation. Such studies directly inform material design and CVD synthesis, and enable new photonic applications and devices based on STMD dressed fiber optics, plasmonic nanostructures, and micro-resonators. The research can potentially lead to new paradigms of STMD functionalized optoelectronics, with examples including parity-time symmetric systems for unidirectional invisibility, nonreciprocal light transmission, novel low-power optical switching and photon routing, ultra-low threshold lasers and amplifiers, TMD-plasmonic systems with nonlinear efficiency enhanced up to several orders of magnitude, and high-efficiency nonlinear/quantum optical devices.
