Dr. Maria Hilse received her B.S. and M.S. in Experimental Physics from Humboldt-University of Berlin in Germany. She joint the Paul-Drude-Institute for Solid State Electronics in 2008 to work on the synthesis and characterization of III-V semiconductor nanowires and ferromagnet-semiconductor nanowire heterostructures by molecular beam epitaxy. In 2015, Dr. Maria Hilse received her Ph. D. in Experimental Physics from Humboldt-University of Berlin, Germany. She then moved on to join the 2D Crystal Consortium, a Materials Innovation Platform of NSF at Penn State. The overarching goal of her research is the synthesis of one- and two-dimensional nanostructures, films and heterostructures by molecular beam epitaxy for applications in energy and environment. She is interested in the experimental study of fundamental growth kinetics of novel materials at the atomic scale to further the understanding of their unique properties and their possible applications. Her research targets electronic and optoelectronic properties arising from strong coupling mechanisms that enable quantum effects, which can be found inherently in materials or engineered by constraining materials in 1D or 2D, manipulating surface configurations and stacking.
2D Semiconductors with High Carrier Mobility
To minimize power consumption and with that the carbon footprint of electronics, we need ultra-thin body, ultra-low power, high performance field effect transistors. 2D materials like InSe and PtSe2 are reportedly a clear and very compelling choice for this application based on their air stability, high carrier mobility and low thermal synthesis budget. I synthesize those materials using different molecular beam epitaxy growth approaches and study their electronic properties in collaboration with density functional theory calculations. Although the molecular beam epitaxy growth approach is successful for both material systems, the high vapor pressure of Se is causing difficulties in achieving high-quality, electronics application grade thin films. One of my current research projects thus focuses on overcoming those challenges for the molecular beam epitaxy growth approach.
2D Layered Piezo- and Ferroelectrics
The addition of new functionalities and capabilities to existing electronics is another way to increase the capability of devices while reducing their power consumption. Adding those to existing electronics is part of another research project of mine. The focus here is on ultra-thin, layered, 2D piezo- and ferroelectric SnSe and In2Se3 thin films and single layers. In collaboration with multiple experimental, reactive force field simulation, and density functional theory groups, I study the growth and properties of those materials using molecular beam epitaxy.
Fundamental Growth Kinetics of Chalcogens and Topological Insulators
In the field of III-V semiconductors, the knowledge gained from fundamental molecular beam epitaxy growth kinetic studies was key for advancing the field to the near perfection level that it is at today. The relatively young field of chalcogen-related research, however, is still plagued by a lack of knowledge regarding basic molecular beam epitaxy growth kinetics. One of my research efforts thus aims on elucidating temperature-dependent chalcogenide growth kinetics in-situ in molecular beam epitaxy using a heated Quartz crystal monitor and Spectroscopic Ellipsometry. Those fundamental growth kinetic studies can be of comparable impact to the field of chalcogen-related research as we have seen in the past for III-V semiconductors.
Interface- and Surface-enabled Quantum Systems
Ultra-clean surfaces and functional interfaces hold the key to high-temperature superconductivity, the observation of quantum phenomena, and many more technological advances. The preparation of such surfaces and interfaces and the mechanisms behind them are, however, in many cases not well understood. Therefore, one of my research efforts focuses on the realization, understanding and application of interface and surface governed effects of strong electronic proximity coupling. The preparation and manipulation of surfaces through high-temperature annealing cycles in air or gases like H2Se, in-situ cleaning and etching of surfaces and interfaces through highly reactive atomic Hydrogen or Oxygen/Nitrogen plasma exposure, and the in-situ molecular beam epitax growth of ultra-clean oxide growth templates that serve as platform for subsequent chalcogenide growth are at the center of this effort.
- Jonathan Chin, Marshall Frye, Derrick S.-H. Liu, Maria Hilse, Ian Graham, Jeffrey Shallenberger, Ke Wang, Roman Engel-Herbert, Mengyi Wang, Yun Kyung Shin, Nadire Nayir, Adri C. T. van Duin, and Lauren Garten, Self-limiting stoichiometry in SnSe thin films, Nanoscale (2023), DOI: 10.1039/d3nr00645j
- Derrick S. H. Liu, Maria Hilse, and Roman Engel-Herbert, Desorption characteristics of selenium and tellurium thin films, J. Vac. Sci. Technol. A 40, 053407 (2022), DOI: 10.1116/6.0002013 · Selected as an Editor’s Pick
- Wouter Mortelmans, Maria Hilse, Qian Song, Seong Soon Jo, Kevin Ye, Derrick Liu, Nitin Samarth, and Rafael Jaramillo, Measuring and Then Eliminating Twin Domains in SnSe Thin Films Using Fast Optical Metrology and Molecular Beam Epitaxy, ACS Nano 16, 6, 9472-9478 (2022), DOI: 10.1021/acsnano.2c02459
- Aofeng Bai, Maria Hilse, Prasanna D. Patil, Roman Engel-Herbert, and Frank Peiris, Probing the growth quality of molecular beam epitaxy-grown Bi2Se3 films via in-situ Spectroscopic ellipsometry, J. Cryst. Growth 591, 126714 (2022), DOI: 10.1016/j.jcrysgro.2022.126714
- Maria Hilse, Ke Wang, and Roman Engel-Herbert, Molecular beam epitaxy of PtSe2 using a co-deposition approach, 2D Mater. 9, 025029 (2022), DOI: 10.1088/2053-1583/ac606f
- Anushka Bansal, Maria Hilse, Benjamin Huet, Ke Wang, Azimkhan Kozhakhmetov, Ji Hyun Kim, Saiphaneendra Bachu, Nasim Alem, Ramon Collazo, Joshua A. Robinson, Roman Engel-Herbert, and Joan M. Redwing, Substrate Modification during Chemical Vapor Deposition of hBN on Sapphire, ACS Appl. Mater. Interfaces 13, 45, 54516-54526 (2021), DOI: 10.1021/acsami.1c14591
- Maria Hilse, Xiaoyu Wang, Phoebe Killea, Frank Peiris, and Roman Engel-Herbert, Spectroscopic ellipsometry as an in-situ monitoring tool for Bi2Se3 films grown by molecular beam epitaxy, J. Cryst. Growth 566-567, 126177 (2021), DOI: 10.1016/j.jcrysgro.2021.126177
- Derrick S. H. Liu, Maria Hilse, and Roman Engel-Herbert, Sticking coefficients of selenium and tellurium, J. Vac. Sci. Technol. A 39, 023413 (2021), DOI: 10.1116/6.0000736
- Tao Liu, James Kally, Timothy Pillsbury, Chuanpu Liu, Houchen Chang, Jinjun Ding, Yang Cheng, Maria Hilse, Roman Engel-Herbert, Anthony Richardella, Nitin Samarth, and Mingzhong Wu, Changes of Magnetism in a Magnetic Insulator due to Proximity to a Topological Insulator, Phys. Rev. Lett. 125, 1, 017204 (2020), DOI: 10.1103/PhysRevLett.125.017204
- Maria Hilse, and Roman Engel-Herbert, Growth of ultrathin Pt layers and selenization into PtSe2 by molecular beam epitaxy, 2D Mater. 7, 4, 045013 (2020), DOI: 10.1088/2053-1583/ab9f91
- 2023 Materials Visualization Competition (MVC15) First Prize – Best in Show (https://sites.psu.edu/mvcs/15-winners/)
- 2015 Caroline-von-Humboldt Fellowship
- 2013-2014 Christiane Nüsslein-Volhard Fellowship