INPhINIT Incoming Fellowship – Ionic 2D Materials: From Synthesis to Devices
eliseo.ruiz@qi.ub.edu
RESEARCH PRODUCT / RESEARCH GROUP
2D materials are a booming topic with a wide variety of applications in many research fields, from optoelectronics, photonics or qubit devices to catalysis. So far, these layered nanoscopic materials have been obtained by different procedures. In top-down approaches, from straightforward mechanical “Scotch tape” exfoliation to liquid exfoliation to break the weak non-covalent interactions between layers. In this project, the challenge is to obtain 2D flakes of a 3D ionic starting material with a cubic rock salt structure (e.g. alkali halides NaCl, NaF, KCl, KF or CsF). They will have physical properties with substantial differences from those of known 2D materials based on layers with covalent bonds. At present, only a few 2D materials (e.g. BN layers) present a large bandgap. This new project proposes 2D materials that will have similar or larger bandgaps. This will open many applications that are now only restricted to the BN layers. The crucial point of this project is to provide a top-down approach to exfoliate an isotropic 3D material with ionic interactions in three spatial directions. Taking as reference the CsF compound, the intercalation of bromine molecules is possible as in other precursors of 2D materials; e.g. graphite/graphene. This intercalation into the 3D structure of the alkali halide has key two effects, one is to generate an anisotropic 2D structure with alternated monoatomic CsF layers and Br2 molecules. The second important effect is that now for the exfoliation of the CsF·Br2 compound only the weak F···Br-Br interactions must be broken. Preliminary DFT calculations indicate that such contact energies are of the same order of magnitude as other non-covalent interactions of common 2D materials. Therefore, the project will focus on the exfoliation of such alkali halides to obtain 2D ionic flakes, to study their physical properties, mainly in large bandgap optoelectronics and photonics (single-photon properties), and those of the related heterostructures
We seek an enthusiastic and highly talented chemist or physicist that is willing to work in an international and interdisciplinary team. The applicant should hold, or be close to completing, a degree or master degree in fields related to physics, chemistry or material sciences. Good verbal and written communication skills in English, and the ability to work well, both individually and as a member of a team, are required. Practical experience in exfoliation and work with 2D materials and related devices will be positively valued. The electronic structure group is part of the Institut de Química Teòrica i Computacional (IQTC), a top-level research institute conducting interdisciplinary research that has been awarded the “Maria de Maeztu” excellence distinction (MDM-2017-0767).
OTHER RELEVANT WEBSITES
related research in the same group
http://www.ee.ub.edu/index.php?option=com_content&view=article&id=79&Itemid=493