Strategic Advances in 2D Materials: Low-Temperature Plasma-Enhanced Chemical Vapor Deposition Growth of Graphene and Complementary Insights into MoS₂

Citation

Lu, Chen-Hsuan (2024) Strategic Advances in 2D Materials: Low-Temperature Plasma-Enhanced Chemical Vapor Deposition Growth of Graphene and Complementary Insights into MoS₂. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/cetf-ns02. https://resolver.caltech.edu/CaltechTHESIS:11082023-043634180

Abstract

This thesis explores the intricate details of the plasma-enhanced chemical vapor deposition (PECVD) technique for growing graphene on various substrates at low temperatures. The research begins by finely optimizing the PECVD growth conditions to produce high-quality graphene on copper ink, which can potentially be used in a wide range of flexible electronics and Internet of Things (IoT) devices. The study also showcases that PECVD is an effective technique for growing graphene directly on electroplated copper over polyimide substrates, which greatly improves the resilience and environmental stability of copper circuits.

Furthermore, the research investigates the possibility of using PECVD to grow graphene on gold, which can be a game-changer in anti-corrosion applications and increase the longevity of gold electrode-based biosensors. The study also makes a significant breakthrough by growing nanocrystalline multilayer graphene on silver in a single step, which demonstrates exceptional oxidation resistance and opens new opportunities for hybrid graphene-silver plasmonic technologies.

Lastly, the thesis examines the potential and complexities of using electrodeposited (ED) copper foil as a graphene growth substrate, showing significant transformations in the properties of the ED copper foil post PECVD process. Towards the latter part of this work, attention is briefly shifted to explore the unique dipole ordering properties of monolayer molybdenum disulfide (MoS2) single crystals, which are synthesized using high-temperature chemical vapor deposition (CVD) and are van der Waals materials like graphene. Although not the main focus, this inclusion offers valuable insights into contrasting attributes and functionalities of graphene and MoS2, especially in areas like high-density data storage and non-volatile memories, and also compares the status of synthesis methods of these two types of van der Waals materials.

Alongside these investigations, the thesis also touches upon the prospects of both large-area PECVD graphene growth and interfacial graphene growth, identifying future paths for research and innovation. This comprehensive study highlights the versatility of low-temperature PECVD for graphene synthesis and provides insights that may reshape research and applications in flexible electronics, biosensing, and beyond. The findings of this research therefore pave ways for researchers, technology developers, and businesses to explore realistic technological applications of graphene and two-dimensional materials in various industries.

Thesis Files