Masoud Lazemi

Masoud Lazemi

PhD candidate

Employed since: April 2021

Supervisors: Frank de Groot & Uwe Bergmann (University of Wisconsin-Madison)
Room: 4th floor open area

Femtosecond XAS and RIXS of Transition Metal Oxides

The advancement of photoanode materials with apt properties plays a pivotal role in photoelectrochemical (PEC) water splitting. As promising candidates, lanthanum (La)-based perovskites bode well for large-scale utilization owing to the high abundance of lanthanum. They are specified by LaBO3 stoichiometry, in which La3+ is the A cation, and the B cation is a trivalent transition metal. By varying the latter, a myriad of La-based perovskites with distinct electrocatalytic performances is attainable.1

The emergence of XFELs, which delve into the atoms and molecules on femtosecond time scales (10-15 s), is an important stepping stone to unprecedented discoveries. Moreover, the development of table-top extreme ultraviolet (XUV)/soft X-ray laser sources with attosecond (10-18 s) pulse employing high-order harmonic generation (HHG) has paved the way to study ultrafast dynamics currently out of reach at the XFELs.2,3 The ongoing research by these state-of-the-art instruments is indeed an auspicious beginning and the dawn of a new era in fundamental science.

Our group has very recently reported the first investigation of the ultrafast charge carrier dynamics in CuWO4 employing time-resolved optical and X-ray spectroscopies,4 in which, an elevated charge density at the Cu site with a decay time of 400 fs has been unveiled by tracking a 50 fs, 3.1 eV optical laser excitation in CuWO4 via a pump-probe delayed X-ray excitation 1.0 eV before the Cu L3 edge (Fig. 1).

In this project, we will prepare LaBO3 (B = transition metal) perovskite samples by the pulsed laser deposition (PLD) technique at Twente University, which will be followed by their preliminary characterization using AFM, STEM, XRD, and XPS techniques. Then, to shed light on the electronic structure of these materials, we intend to utilize both table-top fs soft x-ray sources at the Max Born Institute (MBI) for Nonlinear Optics and Short Pulse Spectroscopy in Germany for 3p XAS and compare the results with fs 2p XAS performed at XFELs, e.g., PAL-XFEL, and static 2p3d RIXS performed at synchrotrons. Furthermore, we will perform multiplet calculations to interpret the fs-XAS and fs-RIXS experiments. In particular, we will further develop the 3p XAS and RIXS calculations.

Fig. 1 (a) The optical and X-ray excitation processes in CuWO4 and the Cu L3-edge transient XAS spectra at a delay time of 10 ps. Illustrations of the charge density at Cu sites in CuWO4 after photoexcitation below a delay of 1 ps (b) and above a delay of 1 ps (c).

1. Dias, J. A. et al. Lanthanum‐Based Perovskites for Catalytic Oxygen Evolution Reaction. ChemElectroChem 7, 3173–3192 (2020)
2. Vura-Weis, J. et al. Femtosecond M2,3-Edge Spectroscopy of Transition-Metal Oxides: Photoinduced Oxidation State Change in α-Fe2O3. J. Phys. Chem. Lett. 4, 3667–3671 (2013).
3. Attar, A. R. et al. Simultaneous Observation of Carrier-Specific Redistribution and Coherent Lattice Dynamics in 2H-MoTe2 with Femtosecond Core-Level Spectroscopy. ACS Nano 14, 15829–15840 (2020).
4. Uemura, Y. et al. Femtosecond Charge Density Modulations in Photoexcited CuWO4. J. Phys. Chem. C 125, 7329–7336 (2021).


Apr 2021 –
PhD Candidate in Materials Chemistry and Catalysis (MCC) Group, Debye Institute for Nanomaterials Science, Utrecht University, The Netherlands.

Early-Stage Researcher (ESR) within Marie Skłodowska-Curie Action – Innovative Training Network (MSCA-ITN) on the Study of carrier transport in MAterials by time-Resolved specTroscopy with ultrashort soft X-ray light (SMART-X)

Supervisors: Prof. Frank de Groot and Prof. Uwe Bergmann (University of Wisconsin-Madison)
Thesis: Femtosecond XAS and RIXS of Transition Metal Oxides

Apr 2019 – Sep 2019
Trainee at MAX IV Laboratory and the Chalmers University of Technology (Prof. Johan Liu Group), Sweden (SESAME – MAX IV)

Training on NEXAFS spectroscopy and XPS to study graphene and carbon nanotubes

Feb 2017 – Mar 2017 and Feb 2019 – Mar 2021
Visiting Scientist and Collaborator at the INFN – National Laboratory of Frascati, Frascati, Rome, Italy.
Prof. Stefano Bellucci Group (NEXT Nanotechnology Group)

My research focused on perovskite solar cells and carbon-based nanomaterials

Jan 2017 – Mar 2017 and Feb 2019 – Mar 2021
Research Assistant at the Faculty of Physics, University of Tabriz, Tabriz, Iran.
Prof. Saeid Asgharizadeh Group

My research focused on perovskite solar cells besides using synchrotron-based techniques such as XAS, SAXS, XRD, and XRF to study nanomaterials and cultural heritage materials.

Apr 2017 – Jan 2019
Alternative civilian service through Iran’s National Elites Foundation

Sep 2014 – Sep 2016
M.Sc. in Photonics – Electronics at the Research Institute for Applied Physics and Astronomy, University of Tabriz, Tabriz, Iran.
GPA: 95.5% (1st rank)
Project: Theoretical and experimental studies of colloidal quantum dot solar cells.

Sep 2010 – July 2014
B.Sc. in Solid-State Physics and Electronics, Faculty of Physics, University of Tabriz, Tabriz, Iran.
GPA: 82.95% (Top 10%)

July 28, 1992
Born in Tabriz, Iran

Playing Tar and Setar (Iranian Musical Instruments), musical composition, Persian calligraphy, and cooking

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