Hyperspectral microscopy

Atomic-scale hyperspectral microscopy: 

atomic-scale structure, electronic, and optical properties

We use and develop characterization techniques to understand the structure and properties of our materials, and to optimize the quality of our synthesis and device fabrication, with in-house technique development of scanning probe microscopy and hyperspectral optical microscopy techniques.

Defects dominate the properties of electronic materials, but it has been challenging to elucidate the role that specific defects play in many 2D materials. This is especially important for functional defects, such as the quantum emitters observed in hBN and transition metal dichalcogenides (e.g., WS2). The Mannix group has a cryogenic, UHV scanning tunneling microscope (STM) to characterize these defects, and correlate their presence with the operation of devices. The STM is equipped with a quartz tuning fork AFM to provide complementary topographical characterization. 

Complementary information is obtained from (scanning) transmission electron microscopy (S/TEM) in the SNSF user facilities. 

Hyperspectral microscopy for material benchmarking

We can grow multiple 4" wafers of material a day, but cleanroom device fabrication and charge transport measurements require many hours of time. As we iterate on material synthesis parameters, it is imperative to have a faster method for benchmarking material quality. 

To address this challenge, we are developing hyperspectral microscopy techniques based on wide-field differential reflectance microscopy to measure spatially-dependent material properties and their evolution over time.