Dr.-Ing. Saskia Schimmel
Chair of Electron Devices
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Emmy Noether Research Group Leader
Spokesperson of DFG Priority Programme "Nitrides4Future"
Dr. Schimmel leads an independent research group funded via the Emmy Noether Programme of the German Research Foundation (DFG), forming the area of expertise Materials synthesis within the Chair of Electron Devices (LEB) at FAU. Her research focuses on nitride semiconductors and their controlled synthesis, properties, and integration into energy-efficient electronic devices.
A key aspect is the ammonothermal crystal growth and the development of methods for in situ observation of dissolution, transport, and growth processes of nitride semiconductors. The work combines experimental high-pressure synthesis, characterization, and modeling-based approaches for the targeted development of materials, technologies, and processes, and establishes a platform for the targeted exploration of new material and process spaces.
The scientific activities, ongoing projects, and team of the Emmy Noether group are presented on the page Nitride Semiconductors (AG Schimmel) .
As spokesperson of the DFG Priority Programme Nitrides4Future, Dr. Schimmel additionally leads national research activities in the field of nitride semiconductors and devices, including their integration into the international reserach community.
2024
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Ammonothermal Crystal Growth of Functional Nitrides for Semiconductor Devices: Status and Potential
In: Materials (2024)
ISSN: 1996-1944
DOI: 10.3390/ma17133104
2023
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Temperature Field, Flow Field, and Temporal Fluctuations Thereof in Ammonothermal Growth of Bulk GaN—Transition from Dissolution Stage to Growth Stage Conditions
In: Materials 16 (2023), p. 2016
ISSN: 1996-1944
DOI: 10.3390/ma16052016
2022
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High-Energy Computed Tomography as a Prospective Tool for In Situ Monitoring of Mass Transfer Processes inside High-Pressure Reactors-A Case Study on Ammonothermal Bulk Crystal Growth of Nitrides including GaN
In: Materials 15 (2022), p. 6165
ISSN: 1996-1944
DOI: 10.3390/ma15176165 - , , :
Artificial Intelligence for Crystal Growth and Characterization
In: Crystals 12 (2022), p. 1232
ISSN: 2073-4352
DOI: 10.3390/cryst12091232
2021
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Numerical simulation of ammonothermal crystal growth of GaN-current state, challenges, and prospects
In: Crystals 11 (2021), Article No.: 356
ISSN: 2073-4352
DOI: 10.3390/cryst11040356 - , , , , , , , :
Boundary conditions for simulations of fluid flow and temperature field during ammonothermal crystal growth—a machine-learning assisted study of autoclave wall temperature distribution
In: Crystals 11 (2021), p. 1-27
ISSN: 2073-4352
DOI: 10.3390/cryst11030254
2020
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Flow stability, convective heat transfer and chemical reactions in ammonothermal autoclaves—insights by in situ measurements of fluid temperatures
In: Crystals 10 (2020), p. 1-18
ISSN: 2073-4352
DOI: 10.3390/cryst10090723
2018
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In situ X-ray monitoring of transport and chemistry of Ga-containing intermediates under ammonothermal growth conditions of GaN
In: Journal of Crystal Growth 498 (2018), p. 214-223
ISSN: 0022-0248
DOI: 10.1016/j.jcrysgro.2018.06.024
2017
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Ammonothermal Synthesis of Earth-Abundant Nitride Semiconductors ZnSiN2 and ZnGeN2 and Dissolution Monitoring by In Situ X-ray Imaging
In: Chemistry - A European Journal 23 (2017), p. 12275-12282
ISSN: 0947-6539
DOI: 10.1002/chem.201701081 - , , , , , , , :
Solubility and dissolution kinetics of GaN in supercritical ammonia in presence of ammonoacidic and ammonobasic mineralizers
In: Journal of Crystal Growth 479 (2017), p. 59-66
ISSN: 0022-0248
DOI: 10.1016/j.jcrysgro.2017.09.027
2016
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Chemical stability of carbon-based inorganic materials for in situ x-ray investigations of ammonothermal crystal growth of nitrides
In: Journal of Crystal Growth 456 (2016), p. 33-42
ISSN: 0022-0248
DOI: 10.1016/j.jcrysgro.2016.08.067
2015
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Ceramic liner technology for ammonoacidic synthesis
In: Journal of Supercritical Fluids 99 (2015), p. 76-87
ISSN: 0896-8446
DOI: 10.1016/j.supflu.2015.01.017 - , , , , , , , , , :
Determination of GaN solubility in supercritical ammonia with NH4F and NH4Cl mineralizer by in situ x-ray imaging of crystal dissolution
In: Journal of Crystal Growth 418 (2015), p. 64-69
ISSN: 0022-0248
DOI: 10.1016/j.jcrysgro.2015.02.020
2014
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Nucleation and growth of polycrystalline SiC
In: IOP Conference Series: Materials Science and Engineering 56 (2014), Article No.: 012001
ISSN: 1757-8981
DOI: 10.1088/1757-899X/56/1/012001 - , , , , , , , , , , :
Advances in wide bandgap SiC for optoelectronics
In: European Physical Journal B 87 (2014)
ISSN: 1434-6028
DOI: 10.1140/epjb/e2014-41100-0 - , , , , , , , , , , :
The role of defects in fluorescent silicon carbide layers grown by sublimation epitaxy
In: IOP Conference Series: Materials Science and Engineering 56 (2014)
ISSN: 1757-8981
DOI: 10.1088/1757-899X/56/1/012002 - , , , , , , , , :
Towards X-ray in-situ visualization of ammonothermal crystal growth of nitrides
In: Physica Status Solidi (C) Current Topics in Solid State Physics 11 (2014), p. 1439-1442
ISSN: 1862-6351
DOI: 10.1002/pssc.201300656
2013
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Towards bulk-like 3C-SiC growth using low off-axis substrates
In: Materials Science Forum 740-742 (2013), p. 275-278
ISSN: 0255-5476
DOI: 10.4028/www.scientific.net/msf.740-742.275 - , , , , , , , , :
Polycrystalline SiC as source material for the growth of fluorescent SiC layers
In: Materials Science Forum 740-742 (2013), p. 39-42
ISSN: 0255-5476
DOI: 10.4028/www.scientific.net/MSF.740-742.39 - , , , , , , , , , , , :
Step-flow growth of fluorescent 4H-SiC layers on 4 degree off-axis substrates
In: Materials Science Forum 740-742 (2013), p. 185-188
ISSN: 0255-5476
DOI: 10.4028/www.scientific.net/MSF.740-742.185
2011
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Structural defects in aluminium nitride bulk crystals visualized by cathodoluminescence maps
In: Physica Status Solidi (C) Current Topics in Solid State Physics 8 (2011), p. 2235–2238
ISSN: 1862-6351
DOI: 10.1002/pssc.201000864
2021
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In Situ Visualization of the Ammonothermal Crystallization Process by X-ray Technology
In: Elke Meissner, Rainer Niewa (ed.): Ammonothermal Synthesis and Crystal Growth of Nitrides, Springer, Cham, 2021, p. 171-190 (Springer Series in Materials Science, Vol.304)
ISBN: 978-3-030-56305-9
DOI: 10.1007/978-3-030-56305-9_10 - , , , :
Special Equipment for Ammonothermal Processes
In: Elke Meissner, Rainer Niewa (ed.): Ammonothermal Synthesis and Crystal Growth of Nitrides, Springer, Cham, 2021, p. 317-328 (Springer Series in Materials Science, Vol.304)
ISBN: 978-3-030-56305-9
DOI: 10.1007/978-3-030-56305-9_17
2026
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Reactor materials and their role in ammonothermal growth of high-purity functional nitrides
14th Annual jDGKK Meeting (Karlsruhe, Germany, 3. March 2026 - 3. March 2026)
2025
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Growth kinetics - a key aspect of every semiconductor synthesis
13th annual meeting of the young crystal growers (jDGKK) (Frankfurt am Main, 4. March 2025 - 4. March 2025) - , , , , :
Emerging research directions in the field of nitride semiconductors
13th annual meeting of the young crystal growers (jDGKK) (Frankfurt am Main, 4. March 2025) - , , , :
Numerical and experimental analysis of ammonothermal crystal growth configurations and their impact on the temperature field along the autoclave wall
International Conference on Nitride Semiconductors - ICNS-15 (Malmö, 6. July 2025 - 11. July 2025)
In: MIKON (ed.): ABSTRACT BOOKLET ICNS 15 2025
Open Access: https://files.mkon.nu/fmfiles/file/Abstractbook_ICNS15_020725_updated-1.pdf
2024
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Fundamentals of ammonothermal growth of nitride crystals
12th Annual jDGKK Meeting (Erlangen, 5. March 2024 - 5. March 2025) - , , , , , :
Transition from etch-back to growth conditions during ammonothermal growth of GaN – a transient numerical model for convective flow and temperature distribution in a retrograde solubility configuration
GaN Marathon (Verona, 9. June 2024 - 12. June 2024) - , :
Nitride semiconductor crystal growth at FAU Erlangen-Nürnberg
12th annual meeting of the young crystal growers (Erlangen, 5. March 2024 - 5. March 2024)
2023
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Junior Research Group on Nitride Semiconductors
Seminar of the Young Crystal Growers (DGKK) (, 14. March 2023)
2022
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High Energy Computed Tomography as a Tool for Validation of Numerical Simulations of Ammonothermal Crystal Growth of GaN
8th International Workshop on Crystal Growth Technology (Berlin, 29. May 2022 - 2. June 2022) - , , , , , , , , , , , , :
In Situ Monitoring Technologies as Prospective Validation Tools for Numerical Simulations of Ammonothermal Crystal Growth
7th European Conference on Crystal Growth (Paris, 25. July 2022 - 27. July 2022) - , , , , , :
Temperature field and fluid flow in ammonothermal growth of GaN during etch-back and crystal growth for a retrograde solubility configuration
International Workshop on Nitride Semiconductors (Berlin, 9. October 2022 - 14. October 2022)
2021
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Numerical Simulations of Ammonothermal Crystal Growth of GaN and Pathways towards their Experimental Validation
Seminar of the Young Crystal Growers (DGKK) (Berlin, 5. October 2022 - 6. October 2021)
2017
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Chemical stability of carbon-based inorganic construction materials for in situ x-ray measurements of ammonothermal crystal growth of nitrides
5th German-Swiss Conference on Crystal Growth (Freiburg, 8. March 2017 - 10. March 2017)
2014
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In Situ Visualization of GaN Crystals in Ammonothermal High Pressure Autoclaves by X-ray Imaging
German Conference on Crystal Growth (Halle, 12. March 2014 - 14. March 2014)
- Open questions in the chemistry of ammonothermal synthesis and crystal growth
(Speech / Talk)
20. March 2026, Event: Chemmy 2026 - Thermal Boundary Conditions in Ammonothermal Crystal Growth – Developing
an Experimentally Validated Numerical Model to Evaluate Effects of Reactor
Materials, Thermal Surrounding, and Active Cooling
(Speech / Talk)
4. March 2026, Event: German Crystal Growth Conference (DKT 2026) - Transient Process Conditions during Ammonothermal Crystal Growth of GaN
(Speech / Talk)
8. September 2025, Event: The 86th JSAP Autumn Meeting 2025URL: https://pub.confit.atlas.jp/en/event/jsap2025a/search?f=schimmel&t=presentation - Ammonothermal crystal growth of nitride semiconductors – investigations via in situ monitoring techniques and numerical modelling
(Speech / Talk)
26. August 2025, Event: 11th International Workshop on Spinel Nitrides and Related Materials - Wurtzite nitrides with enhanced piezo- and ferroelectric properties – application prospects and synthesis challenges
(Speech / Talk)
7. March 2025, Event: CHEMMY 2025 - Thermal environment of autoclaves for ammonothermal crystal growth – towards a simulation-based analysis of the thermal effects of selected design variables of the experimental setup
(Speech / Talk)
5. March 2025, Event: DGKK AK Machine Learning and Simulation - Emerging Nitride Semiconductors and their Synthesis via the Ammonothermal Method
(Speech / Talk)
29. February 2024, Event: Chemistry Emmy Noether Treff - Transient conditions during ammonothermal growth of GaN during the transition from etch-back to growth conditions - a numerical study for a retrograde solubility configuration
(Speech / Talk)
15. March 2023, Event: German Conference on Crystal Growth - Opportunities and challenges for the use of machine learning in university research and teaching
(Speech / Talk)
15. March 2023, Event: DGKK Schwerpunkt Machine Learning - Machine learning Assisted Physics based Numerical Modelling an Application Example from Ammonothermal Crystal Growth
(Speech / Talk)
15. March 2023, Event: DGKK Schwerpunkt Machine Learning - Artificial Intelligence in the Materials Research
(Speech / Talk)
16. June 2021, Event: Advanced Materials Conference - To innovate in the future, the journey starts here - Simulation of the Global Thermal Field in a Setup for Ammonothermal Growth of GaN
(Speech / Talk)
17. March 2021, Event: 68th Japan Society of Applied Physics Spring Meeting - Evaluation of Realistic Boundary Conditions for Simulations of Ammonothermal GaN Crystal Growth
(Speech / Talk)
2. March 2021, Event: 8th Asian Conference on Crystal Growth and Crystal Technology - Numerical Simulation of the Ammonothermal Growth Process of GaN - Effect of Thermal Boundary Conditions on Flow Field and Temperature Distribution
(Speech / Talk)
20. November 2020, Event: Center for Integrated Research of Future Electronics GaN Webinar Series Poland-Japan (Unipress - Nagoya University) Seminar on GaN - In Situ X-Ray Monitoring of Ammonothermal Reaction Processes for Advancing the Understanding of Ammonothermal GaN Growth
(Speech / Talk)
29. November 2019, Event: 16th Akasaki Research Center Symposium "To the New Horizon of the Nitride Research" - Insights into Ammonothermal Autoclaves by X-Ray-based In Situ Measurement Techniques
(Speech / Talk)
20. February 2018, Event: Annual meeting of ProcessNet group for high pressure process technology, Gesellschaft für Chemische Technik und Biotechnologie - Insights into Ammonothermal Growth of Nitrides by In Situ Measurement Techniques
(Speech / Talk)
12. October 2017, Event: DGKK Workshop on bulk semiconductor crystals - Insights into the Ammonothermal Growth Process of GaN by In Situ X-Ray Visualization
(Speech / Talk)
21. September 2017, Event: International Workshop on Bulk Nitride Semiconductors - Towards Improved Understanding of Ammonothermal Crystal Growth - Insights by In Situ X-ray Imaging of GaN Dissolution
(Speech / Talk)
13. October 2016, Event: DGKK Workshop on bulk semiconductor crystals - GaN Solubility and Dissolution Kinetics Investigated Using Direct Insight into Ammonothermal Autoclaves by In Situ X-Ray Imaging
(Speech / Talk)
5. October 2016, Event: International Workshop on Nitride Semiconductors - Solubility and Dissolution Kinetics of GaN under Ammonobasic Conditions using NaN3 Mineralizer
(Speech / Talk)
17. March 2016, Event: 1st German Czechoslovak Conference on Crystal Growth - In Situ X-Ray Imaging of GaN under Ammonothermal Conditions - Application for GaN Solubility Measurements
(Speech / Talk)
6. March 2015, Event: German Conference on Crystal Growth (DKT 2015) - Towards X-Ray In-Situ Visualization of Ammonothermal Crystal Growth of Nitrides via Hydrothermal Crystallization of Zeolites
(Speech / Talk)
20. September 2013, Event: European Materials Research Society Fall Meeting, European Materials Research Society - The Role of Defects in Fluorescent Silicon Carbide Layers Grown by Sublimation Epitaxy
(Speech / Talk)
28. May 2013, Event: European Materials Research Society Spring Meeting, European Materials Research Society
- : BRIDGE fellowship (Japan Society for the Promotion of Science (JSPS)) – 2025
- : IUCr Young Scientist Award (International Union of Crystallography) – 2022
- : Emerging Talents Initiative (ETI) (Friedrich-Alexander-Universität Erlangen-Nürnberg) – 2022
- : Feodor Lynen Return Fellowship (Alexander von Humboldt-Stiftung) – 2021
- : Postdoctoral Fellowships for Research in Japan (Standard) (Japan Society for the Promotion of Science (JSPS)) – 2019
- : ISASF best PhD thesis award (2nd prize) (International Society for Advancement of Supercritical Fluids (ISASF)) – 2019
- : Promotionsstipendium (1 year) (Erika Giehrl-Stiftung) – 2014
- : Stipendium für Masterarbeit an der Universität Linköping (Schweden) (German Crystal Growth Association (DGKK)) – 2012
- : Stipendium für Studiensemester an der Universität Linköping (Schweden) (Prof. Dr.-Ing. Erich Müller-Stiftung) – 2011
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KI-Fähigkeiten für Elektroingenieur*innen: Entfachen von KI-unterstützter Innovation
(FAU Funds)
Project leader: ,
Term: 1. October 2024 - 30. September 2025
Acronym: KI-FUNKEN -
Emmy Noether-Programme „Novel nitride materials for electronic devices“ (1st period of funding)
(Third Party Funds Single)
Project leader:
Term: 1. August 2023 - 31. July 2026
Funding source: DFG-Einzelförderung / Emmy-Noether-Programm (EIN-ENP)The overall goal of the project is to develop selected emerging nitride semiconductors alongside with an improved and more generalizable understanding of ammonothermal growth of nitrides. The project evaluates the fundamental properties of selected emerging ternary nitrides with regard to prospective applications in electronic devices. Bulk crystals will be grown via the ammonothermal method. Alongside with gaining access to the materials, a deepened understanding of the ammonothermal synthesis and doping of binary and ternary materials will be established. The targeted nitrides are suitable for heteroepitaxial integration with each other, which prospectively enables novel combinations of materials properties in electronic devices. Building on previous results on GaN, the material system GaN-AlN-AlGaN will first be investigated. AlGaN will serve as an exemplary case for studying ways of controlled crystallization of ternary nitrides via solute transport in ammonothermal solutions. Methods of intentional doping and conductivity control during ammonothermal crystal growth will be investigated using AlN as an example. The low growth temperatures enabled by ammonothermal synthesis represent a prospective pathway to conductive AlN substrates via doping with Si, which could enable significant improvements in the energy efficiency of vertical power electronic devices. The use of custom high-pressure optical cells creates unique capabilities for monitoring ammonothermal reactions in situ. In the case of Ga, these will be utilized to deepen the fundamental understanding. In situ monitoring will also be applied for expanding the fundamental understanding to the constituent elements of the ternary nitrides targeted in the project, specifically Al, Si, Mg, Mn and Zn. In parallel, in situ monitoring methods for investigating complex systems will be developed further, namely simultaneous in situ measurements with complementary techniques such as x-ray absorption, UV-Vis- and Raman spectroscopy. In addition, the roles of pressure and ammonia density for crystallization will be clarified and the feasibility of crystallization at significantly lower pressures will be evaluated. Within the project, the obtained understanding of the crystallization of ternary nitrides and their transport in ammonothermal fluids will be utilized for the crystallization of three emerging ternary nitride materials of the composition II-Si-N2 (II = Mg, Mn, Zn). Their synthesis as single crystals of good structural quality enables the experimental evaluation of their bulk properties. Building on the obtained knowledge of the properties of these materials, their application prospects in electronic devices will be evaluated further, including a first evaluation of the application potential of epitaxial heterostructures of the investigated materials.
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High-energy computed tomography for in situ observation of processes taking place inside high-pressure vessels - development using the example of ammonothermal crystal growth of GaN
(FAU Funds)
Project leader:
Term: 15. January 2023 - 14. January 2024 -
Paving the way for validation of numerical simulations of ammonothermal crystal growth via in situ monitoring technology
(Third Party Funds Single)
Project leader:
Term: 1. August 2021 - 31. July 2022
Funding source: Alexander von Humboldt-Stiftung -
Ammonothermal growth of low dislocation density, high purity bulk GaN for power electronic devices
(Non-FAU Project)
Project leader:
Term: 31. May 2019 - 30. May 2021
Funding source: andere Förderorganisation
Further information can be found here: ORCiD, Scopus, ResearchGate, Google Scholar, LinkedIn.