Ultrafast AFM

Research Interests

• 2D materials

• Thin film molecule samples

• Defects

Motivation

Understanding the fundamental properties of nanomaterials has potential applications in areas including solar cell devices and molecular materials.

Ultrafast AFM

The Ultrafast AFM technique was first developed in our group by Schumacher et al. in 2017 by combining an ultrafast laser with non-contact AFM. When the laser impinges on the sample, it generates a photoinduced sample response, which is then detected as a force by the AFM tip. The temporal resolution of this technique is afforded by the ultrafast laser, and reaches the femtosecond regime. The spatial resolution is afforded by the sharpness of the AFM probe, and reaches the nanometer regime. This unique combination of spatial and temporal resolution will allow us to characterize local recombination rates and carrier decay times in photovoltaic materials.

General

• Three chamber ultrahigh vacuum system: quick load lock chamber, specimen treatment chamber, analysis chamber

• Base pressure in treatment and analysis chambers less than 10e-8 Pa

Specimen Treatment Chamber

• LEED/Auger spectrometer

• Four-source e-beam evaporator for the deposition of metals

• Three source evaporator for the deposition of organic molecules

• Quartz crystal deposition monitor for determining thickness of evaporated films

• Ion gun

• Specimen cleaving device

• In situ mask system for depositing macroscopic electrode patterns (designed in-house)

People

Group Members

• Megan Cowie (PhD student)

• Josephine Spiegelberg (Masters student)

Former Group Members

• Rikke Plougmann (PhD student)

• Andreas Spielhofer (PhD graduate '19)

• Rasa Rejali (Master graduate)

• Zeno Schumacher (PhD graduate)

• Antoni Tekiel (PhD graduate '13)

• Jessica Topple (PhD graduate '12)

• Shawn Fostner (PhD graduate '10)

• Sarah Burke (PhD graduate '09)

• Jeffrey Mativetsky (PhD graduate '06)

Collaborators

• David Cooke (McGill University)

• Carlos Silva (Université de Montréal)

• Hong Guo (McGill University)

• Regina Hoffmann (University of Karlsruhe, Germany)

• Yoichi Miyahara (McGill University)

Recent publications

• Z. Schumacher, Y. Miyahara, A. Spielhofer, and P. Grutter: "Measurement of Surface Photovoltage by Atomic Force Microscopy under Pulsed Illumination" , Phys. Rev. Applied 5, 044018 (2016)

• A. Tekiel, Y. Miyahara, J. M. Topple, and P. Grütter: "Room-Temperature Single-Electron Charging Detected by Electrostatic Force Microscopy", ACS Nano 7, 4683–4690 (2013)

• A. Tekiel, S. Fostner, J. M. Topple, Y. Miyahara, and P. Grütter: "Reactive growth of MgO overlayers on Fe(001) surfaces studied by low-energy electron diffraction and atomic force microscopy", Appl. Surf. Sci. 273, 247-252 (2013)

• A. Tekiel, J. M. Topple, Y. Miyahara, and P. Grütter, "Layer-by-layer growth of sodium chloride overlayers on the Fe(001)-p(1x1)O surface", Nanotechnology 23, 505602 (2012)

• D. Stoffler, F. Fostner, P. Grütter, R. Hoffmann-Vogel, "Scanning probe microscopy imaging of metallic nanocontacts", Phys. Rev. B 85, 033404 (2012)

• S. Fostner, A. Tekiel, J.M. Topple, Y. Miyahara and P. Grütter, "Field deposition from metallic tips onto insulating substrates", Nanotechnology 22, 465301 (2011)

• J. Topple, S.A. Burke, W. Ji, S. Fostner, A. Tekiel, P. Grutter, "Tailoring the Morphology and Dewetting of an Organic Thin Film", J. Phys. Chem. C 115(1), 217 (2011)