Tuesday, June 16, 20153:30 PM - 5:00 PMCNLS Conference Room (TA-3, Bldg 1690)|
Strong excitonic effects in novel 2D semiconductors: Overview and Quantum Monte
Kirill A. Velizhanin T-1
Two-dimensional (2D) semiconductors are materials that combine unique properties of graphene - flagship of 2D materials - with the existence of finite band gap required for multiple applications including electronics and photonics. One of the most promising classes of 2D semiconductor materials is transition metal dichalcogenide monolayers (e.g., MoS2). A striking feature of these materials, as well as 2D semiconductors in general, is a strong Coulomb interaction between charge carriers resulting in large excitonic effects. In particular, this leads to formation of multi-carrier bound states upon photoexcitation (e.g., excitons, trions and biexcitons), which could remain stable at near-room temperatures and contribute significantly to optical properties of such materials. In this talk, I will overview the physics of excitonic effects and importance of these effects from both basic and technological standpoints. In the second half of the talk, I will report on our recent progress in using the Path Integral Monte Carlo methodology to accurately analyze various properties of multi-carrier bound states in 2D semiconductors. Specifically, I will talk about how the obtained numerical results could be directly used to analyze experimental data.
Host: Mila Adamska