Leiden University Student Repository

Beest, Jay te (2025)

In situ Development of Cs3Sb Photocathodes for Optical Near-Field Electron Microscopy

Master thesis | Physics (MSc)

In this thesis, we investigate the co-deposition of cesium and antimony to develop efficient Cs3Sb photocathodes for Optical Near-field Electron Microscopy (ONEM), aiming to achieve ultra-smooth, ultra-thin photocathodes with high quantum efficiency. The project involved implementing, designing and calibrating new equipment, such as a Dual Cluster Source evaporator, a Quartz Crystal Monitor, a QE measurement setup and a custom transfer arm extension with sample heater for temperature controlled growth. All the equipment is installed in the preparation chamber of the ESCHER LEEM, where we have successfully grown several photocathodes. Ultimately, a photocathode grown in the preparation chamber, with a measured moderate QE of around 0.3% at 450 nm light, has been successfully utilized for the first time to obtain an ONEM image of a biological sample.

Microscopy

ONEM

LEEM

Photocathode

Cs

Sb

Author

Beest, Jay te

Faculty

Faculty of Science

Specialisation

Quantum Matter and Optics

Supervisors

van der Molen, S.J.

ECTS Credits

24

Language

en