SPM-Lab
The Scanning Probe Microscopy Laboratory was founded in 2017 by Alex Redinger in a framework of an FNR consolidator grant.
The group focuses on the study of the surface of two types of thin film solar cells, namely Cu(In,Ga)Se2 (CIGSe) and hybrid organic inorganic perovskites, as well as 2D materials. We combine scanning probe microscopy techniques in ultra-high vacuum such as Scanning Tunneling Spectroscopy (STS) and Kelvin Probe Force Microscopy (KPFM) and photoluminescence imaging (PL/TRPL) to access the electrostatic and optoelectronic properties at the surface of semiconductors.
Latest News
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22/04/2024
New paper:
Jonathans paper on:
Modification of Mono-layer MoS2 Through Post-Deposition Treatment and Oxidation
for Enhanced Optoelectronic Properties
has been published in APL Materials
Authors are: Jonathan Rommelfangen, Marco A. Gonzalez-Angulo, Devendra Pareek, Levent Gütay,
Phillip J. Dale, and Alex Redinger
https://doi.org/10.1063/5.0189378
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01/03/2024
New paper:
Himanshus paper on:
Quantifying recombination and charge carrier extraction in halide perovskites via hyperspectral time-resolved photoluminescence imaging
has been published in APL Energy
Authors are: H. Phirke S. Gharabeiki A. Singh A. Krishna S. Siebentritt A. Redinger
https://doi.org/10.1063/5.0188166
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13/02/2024
News and Views article
Alex wrote a "News and Views" article, which has been published in Nature Energy:
Carrier concentration resolved
https://doi.org/10.1038/s41560-024-01460-7
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08/12/2023
New PhD position avaiable in my group: Position filled!!
Please use the following link to apply.
http://emea3.mrted.ly/3kg8r
A few more details on the project. This is an FNR funded project focussed on a material class named CIGSe, which is used to make very effcient thin film solar cells. In this project, there will be two PhD positions available. One in the group of Prof. Susanne Siebentritt and one in my group. We will receive epitaxially grown CIGSe absorbers from the Siebentritt group and will study the cleaved surfaces of CIGSe. This will be done with AFM, KPFM and STM. The goal is to atomically resolve the CIGSe cross section, identidy defects and disorder in the material. Furthermore, we want to study full devices in cross section via KPFM. The measurements will be carried out in UHV with an Omicron VT system and with a Park Systems AFM system, that was recently aquired in our department and that will arrive early next year.
I need a very motivated student with an excellent background in solid state physics and semiconductors. Previous experience with scanning probe techniques are certainly an advantage.
Looking forward to your application
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01/12/2023
New paper in Energy & Environmental Science;
Understanding and decoupling the role of wavelength and defects in light-induced degradation of metal-halide perovskites (rsc.org)
Why do halide perovskites become unstable and decompose when illuminated. One important aspect is excess PbI2. We show how PbI2 acts as seeds for decomposition, we show that the light induced deterioration depends on the wavelength. Experimental data is supplemented with DFT calculations to better understand why and under which circumstances the perovskites decompose. Samples from EPFL, DFT calculations performed in the Tkatchenko group at UL, HIM SIMS mapping performed at LIST, XPS, KPFM, STM performed by the SPM group.
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12/05/2023
New paper in ACS Energy Letters in collaboration with the Saliba group in Stuttgart
Light makes right: laser polishing for surface modification of perovskite solar cells
We performed the PL imaging and AFM/KPFM measurements.
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07/05/2023
New paper from our group in Advanced Functional Materials:
Nanoscale Surface Analysis Reveals Origins of Enhanced Interface Passivation in RbF Post Deposition Treated CIGSe Solar Cells
Nice collaboration between UL, EMPA and LIST.
Recent Publications
December 2023
Understanding and decoupling the role of wavelength and defects in light-induced degradation of metal-halide perovskites
Jeremy Hieulle, Anurag Krishna, Ariadni Boziki, Jean-Nicolas Audinot, Muhammad Uzair Farooq, Joana Ferreira Machado, Marko Mladenovic´, Himanshu Phirke, Ajay Singh, Tom Wirtz, Alexandre Tkatchenko, Michael Graetzel, Anders Hagfeldt and Alex Redinger
Energy Environ. Sci. (2023)
August 2023
Mitigating the Heterointerface Driven Instability in Perovskite Photovoltaics
Anurag Krishna, Viktor Skorjanc, Mathias Dankl, Jeremy Hieulle, Himanshu Phirke, Ajay Singh, Essa A Alharbi, Hong Zhang, Felix Eickemeyer, Shaik M Zakeeruddin, GN Manjunatha Reddy, Alex Redinger, Ursula Rothlisberger, Michael Gratzel, Anders Hagfeldt
ACS Energy Lett. 2023, 8, 8, 3604–3613
May 2023
Light Makes Right: Laser Polishing for Surface Modification of Perovskite Solar Cells
Mayank Kedia, Monika Rai, Himanshu Phirke, Clara A Aranda, Chittaranjan Das, Vladimir Chirvony, Stephan Boehringer, Małgorzata Kot, Mahdi Malekshahi Byranvand, Jan Ingo Flege, Alex Redinger, Michael Saliba
ACS Energy Lett. 2023, 8, 6, 2603–2610
May 2023
Nanoscale Surface Analysis Reveals Origins of Enhanced Interface Passivation in RbF Post Deposition Treated CIGSe Solar Cells
Christian Kameni Boumenou, Himanshu Phirke, Jonathan Rommelfangen, Jean‐Nicolas Audinot, Shiro Nishiwaki, Tom Wirtz, Romain Carron, Alex Redinger
Adv. Funct. Mater.2023, 33, 2300590
August 2022
Coevaporation Stabilizes Tin-Based Perovskites in a Single Sn-Oxidation State
Ajay Singh, Jeremy Hieulle, Joana Ferreira Machado, Sevan Gharabeiki, Weiwei Zuo, Muhammad Uzair Farooq, Himanshu Phirke, Michael Saliba, Alex Redinger
Nano Letters 22 (17), 7112-7118
July 2022
Surface Passivation and Detrimental Heat-Induced Diffusion Effects in RbF-Treated Cu(In,Ga)Se2 Solar Cell Absorbers
Amala Elizabeth, Sudhir K Sahoo, Himanshu Phirke, Tim Kodalle, Thomas D Kühne, Jean-Nicolas Audinot, Tom Wirtz, Alex Redinger, Christian A Kaufmann, Hossein Mirhosseini, Harry Mönig
ACS Applied Materials & Interfaces 14 (29), 34101-34112
June 2022
The impact of strain on growth mode in chemical vapor deposited mono- and few-layer MoS2
J Rommelfangen, S Reichardt, V Ben Chu, L Wirtz, PJ Dale, A Redinger
AIP Advances 12 (6), 065010