Advances in the Analysis of 2D Transition Metal Dichalcogenides Using Scanning Probe Microscopy Techniques
Dr. Albert Minj
Considering their unparalleled material characteristics and extensive application potential, twodimensional (2D) materials have become the focal point within the research community for several applications [1]. Transition metal dichalcogenides (TMDs) are particularly promising for use in field-effect transistors (FETs) to sustain scaling trends in complementary metaloxide-semiconductor technology [2], as well as in photonics and sensing applications. This talk offers a comprehensive overview of critical characterization and analysis techniques essential for optimizing these materials, both in their as-grown state and within device contexts.
The first part of the talk addresses the characterization of as-grown 2D materials, with a focus on TMDs. Despite their promise, these materials are highly sensitive to ambient interactions, which can lead to inaccuracies in quality assessments. Advanced scanning probe microscopy (SPM) techniques performed under (ultra) high vacuum conditions, are employed to gain insights into the adsorption-desorption mechanisms, and to understand interface charges and conductivity [3]. These techniques reveal that species like water molecules rapidly adsorb and likely intercalate upon exposure to the atmosphere, significantly impacting the electronic properties and performance of the materials. Understanding these interactions is crucial for developing reliable characterization methods and improving material performance.
The second part of the talk shifts focus to the in-operando characterization of field-effect transistors (FETs) incorporating TMDs as channel [4]. As device performance is often compromised by defects that introduce variability and degrade current transport properties, analysis of surface potential and differential capacitance in monolayer TMD channels of operating FETs facilitates the identification and understanding of defects such as grain boundaries and bilayer island edge sites. This understanding is pivotal for addressing defectrelated challenges and enhancing device performance.
Overall, these studies emphasize the importance of robust characterization techniques for both as-grown 2D materials and their device applications. Advancing the understanding of these materials from synthesis to operation is key to unlocking their full potential for industrial applications