2D materials: from scalable MOCVD growth to quantitative structural characterization at the atomic scale
Two-dimensional materials are prime contenders to enhance semiconductor technology. Their rich compositional and stacking varieties yield virtually endless possibilities to tailor device properties. For example, monolayer GaS exhibits a bandgap in the ultraviolet and could yield solar-blind photodiodes or even replace GaN as emitter in LEDs covering the whole visible spectrum.
However, any commercial success requires wafer-scale integration rather than growth or fabrication without upscaling possibilities like, e.g., exfoliation. Here we show that metal organic chemical vapor deposition allows a one-step growth process of monolayer GaS on sapphire substrates and reveal the interface chemistry and resulting epitaxial relationship. Pulsed-mode deposition of industry-standard precursors drastically inhibits vapor-phase pre-reactions and fosters monolayer growth. Structure-revealing and composition-sensitive probes confirm the quality and monolayer properties. To this end, we employ various sophisticated transmission electron microscopy-based methods to quantify defects, the atomic reconstruction as well as charge redistribution and electronic excitations in monolayer as well as twisted (hetero)bilayer 2D materials.
She received her diploma in physics from Augsburg university in 1996. In 1999 she obtained her PhD from the same university. After several research visits at Osaka National Research Institute/Japan and Nagasaki Institute of Technology/Japan and a postdoctoral stay at Stanford University/USA she joined Philipps-Universität Marburg as a Junior Group leader. After a professorship at the Humboldt-Universität zu Berlin, she was appointed as a professor in Marburg. She served as speaker of the Research Training Group “Functionalization of Semiconductors” (2012-2022) and currently is the spokesperson of the Collaborative Research Center “Structure and Dynamics of internal Interfaces, both financed by the German Research foundation (DFG). She received the following awards: Graduate Student Award of EMRS (1996); Feodor-Lynen scholarship of Alexander von Humboldt foundation (2001); guest professorship of Humboldt Universität zu Berlin (2008); Heisenberg professorship of German Research Foundation (2008); Patricia Pahamy Price for best teaching (2009); Greve-prize of the Leopoldina (2022).
Her research interests include the synthesis (MOVPE) and quantitative transmission electron microscopy of novel functional materials.