Proximity doping effects in epitaxial graphene: substrate, growth and post-growth treatment

点击翻译按钮获取中文摘要

The position of the Fermi level and thus the carrier density of epitaxial graphene is a key property for various device applications. Achieving a well-defined and highly homogeneous carrier density is crucial for applications in electrical quantum metrology, specifically for the realization of quantum Hall standards in low magnetic field. On the other hand, a controlled variation of the carrier density will allow realization of p-n-junctions enabling novel device applications and the access to fundamental effects such as Klein tunneling. Therefore, this project aims at realizing large area epitaxial graphene systems with the highest possible control of the carrier density. Growing large area graphene with low step heights on specific SiC facets, only, will allow to obtain a highly homogeneous carrier density allowing full quantization in lowest possible fields. In contrast, growth on alternating facets will be explored to realize lateral doping modulation and lateral p-n-junctions. The facet induced doping will be combined with polymer-based post-growth molecular doping to realize various devices with optimized properties for both electrical quantum metrology and fundamental experiments.