2DCC In-House Research Highlight

Although doping with alkali atoms is a powerful way to introduce charge carriers into 2D systems, the resulting doped materials are often not air stable. A team of 2DCC researchers and external users has designed a strategy to increase the stability of alkali-doped materials by using stoichiometrically unbalanced salt crystals with excess cations; the salt crystal acting as a template to stabilize the excess dopant atoms against oxidation.

Project Summary: Among the high-mobility two-dimensional transition metal dichalcogenides, PtSe2 is of particular interest due to its record high carrier mobility of 210 cm2/Vs, sizeable band gap and air stability to address the current need for low-power, high-performance and ultra-thin body electronics. A scalable fabrication process with highly precise thickness control on ultra-smooth insulating gate oxides however has not been achieved to date. This work is addressing this gap by presenting ultra-thin growth of PtSe2 layers on insulating Al2O3.

Project Summary: Atomic-level probing and controlling epitaxial graphene (EG) defects constitutes a key step in the

Project Summary: Contemporary approaches to non-volatile magnetic random access memory (MRAM) rely on using an electrical current (charge) to change the magnetization (spin) of a ferromagnetic material.

Project Summary: The two-dimensional semiconductors phosphorene and isoelectronic SnS have attracted extensive research interest for potential applications in optoelectronics, spintronics, catalysis, sensors, and energy conversion. We performed density functional theory (DFT) calculations to accurately compute formation energies, charge transition levels, and electronic properties of vacancies in both materials utilizing a correction scheme to ensure appropriate electrostatic boundary conditions for charged defects in 2D materials.

What Has Been Achieved:

What Has Been Achieved:

We developed and validated a ReaxFF description for Ba/SrTiO3 perovskites.

Importance of the Achievement:

These ReaxFF parameters can be straightforwardly combined with existing ReaxFF descriptions for Mo/W/Se/S/C/O/H, enabling simulations of MoWSeS-material growth on STO support.

Unique Feature(s) of the MIP that Enabled this Achievement:

This work responds to a continuing external user interest in ReaxFF parameters for 2D materials and their growth substrates

What Has Been Achieved:

We carried out a careful study of the effect of 3 different capping layers on interfacial superconductivity in FeSe/SrTiO3 heterostructures.

Importance of the Achievement:

What Has Been Achieved:

A new ReaxFF potential for large-scale simulations of structural engineering and synthesis of Two-dimensional WSe2 has been made available to the 2D community

Importance of the Achievement:

What Has Been Achieved:

We used MBE to Dirac semimetal/ferromagnet metal (Cd3As2/Ni0.8Fe0.2) heterostructures and measured spin-charge interconversion using spin pumping and spin torque ferromagnetic resonance. Importance of the Achievement: This work showed efficient spin-charge interconversion in a Dirac semimetal and revealed a surprising enhancement in the interconversion efficiency with an oxidized interface.

Unique Feature(s) of the MIP that Enabled this Achievement: