Theory Leading Experiment: ReaxFF simulations on the growth of SnSe Thin Films Using Graphene Mask in MBE

Project Summary: Controlled thin film growth via molecular beam epitaxy
(MBE) is pivotal in tuning material properties for various applications. Addressing
challenges in thin film fabrication, such as island growth modes and
morphological irregularities is essential for enhancing material and device
performance. This study reports an atomic-level investigation of the selective
area nucleation of SnSe on a MgO(001) substrate via MBE, using ReaxFF
reactive molecular dynamics (MD) simulations. By employing graphene masks
for selective area nucleation, we examined the impact of mask usage and
thickness on the morphology of the deposited SnSe. Based on the MD
simulations, a single-layer graphene mask promotes the nucleation of the
crystalline P3̅m1 phase of SnSe2. Furthermore, the use of multiple thermostats
in the simulations mitigates gas-phase SnxSey clustering, allowing for a more
accurate representation of MBE conditions and offering deeper insights into the
nucleation mechanism. This study provides an atomic-level insight into the
selective area nucleation in thin film deposition processes.

Publication: B. Fazlioglu-Yalcin, M. Wang, N. Nayir, S. Law, A. van Duin.
“Atomic Level Insight into the Nucleation of SnSe Thin Films Using Graphene
Mask in Molecular Beam Epitaxy: ReaxFF Molecular Dynamics Simulations” J.
Phys. Chem. C 2024, 128, 34, 14294–14304. DOI: 10.1021/acs.jpcc.4c03096

2DCC Role: The 2DCC facility was utilized for ReaxFF force field development
and molecular dynamics simulations to model SnSe nucleation on MgO(001)
with a graphene mask.