Computational design of stacked heterostructures from low-dimensional materials for strategic applications
Abstract
Transition metal dichalcogenides, two-dimensional (2D) phosphorus (a.k.a. phosphorene) and many other crystalline solids in the materials ÒflatlandÓ, as well as carbon nanotubes represent a diverse pool of low dimensional materials that, when combined into heterostacks, will produce new derivatives with tunable properties, presenting new opportunities to both fundamental materials science and device applications. Although many aspects of the individual single-layer materials are well studied, the effects produced by structural irregularities (point defects, dislocation grain boundaries, edges) require better understanding since they critically affect the overall performance. Moreover, combinations of 2D-layers in coplanar hybrids or into vertical stacks are less explored while offering valuable opportunities for discovering new physics and device functionality. Detailed understanding of many aspects of these new heterostructures is a critical prerequisite for any strategic, especially Army-related, applications. The goal of this project is to theoretically investigate specific properties of stacked heterostructures as well as form generalized theory of their behavior and consider possible applications. The optical transitions in the 2D materials are not very well studied and of particular interest to the project. To this goal, we would employ the state-of-the-art computational framework to first investigate effects of structural imperfections on the optical properties of individual single layers of transition metal dichalcogenides (TMDC). This will then allow detailed insights to be gained into nature of excitonic transitions between spatially separated electron-hole pairs and lifetimes of the transitions in the simplest case of hetero bilayers, and to reveal the origins of experimentally reported important features (e.g., puzzling photoluminescence patterns). Specific attention will also be paid to the influence of incommensurate versus commensurate bonding at the interfaces on the optical properties and effects of curvature will be analyzed for the example of the archetypal double-walled carbon nanotube system. Successful completion of the proposed project will provide crucial insights for the practical realization of useful heterostructures based optical/electronic devices.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 04, 2018
- Source ID
- W911NF1610255
Entities
People
- Boris I Yakobson
Organizations
- Army Contracting Command
- Rice University
- United States Army