Nanostructures
Investigated by the group are metal and semiconductor nanostructures and their hybrids by transport measurements. The nanostructures are made by bottom-up and top-down fabrication techniques. Electrical contacts to single nanostructures, such as nanowires, are made by micro- and nanolithography.
Studied are the size effects of the conductivity, magnetoresistance, thermopower and thermal conductance with respect to varying electrical fields, low- and high-magnetic fields and temperature.
Of particular interest is the determination of thermal transport properties at the nanoscale and in developing the required measurement techniques. Materials presently under investigation are metal-based (Ag, Ni, Co...), Si-based, and Bi2-based (Bi2Se3, Bi2Te3,...) nanostructures and core-shell nanowires.
Novel Materials Group
Prof. Dr. Saskia F. Fischer email
Associated researchers
Dr. Rüdiger Mitdank email
MSc. Mahni Müller email
Further research topics
Ultra-thin layers | Quantum systems | Novel semiconductor materials
Selected Publications
Semimetal to semiconductor transition in Bi/TiO2 core/shell nanowires
M. Kockert, R. Mitdank, H. Moon, J. Kim, A. Mogilatenko, S. H. Moosavi, M. Kroener, P. Woias, W. Lee, and S. F. Fischer
Nanoscale Adv. 3, 263 (2021).
DOI:10.1039/d0na00658k
Short abstract
Nanometrology: Absolute Seebeck coefficient of individual silver nanowires
M. Kockert, D. Kojda, R. Mitdank, A. Mogilatenko, Z. Wang, J. Ruhhammer, M. Kroener, P. Woias, and S. F. Fischer
Scientific Reports 9, 20265 (2019).
DOI:10.1038/s41598-019-56602-9
Short abstract
Helmholtz Prize 2020 in the category “Applications”
Absolute Seebeck coefficient of thin platinum films
M. Kockert, R. Mitdank, A. Zykov, S. Kowarik, and S. F. Fischer
Journal of Applied Physics 126, 105106 (2019).
DOI:10.1063/1.5101028
Short abstract
Perfect quintuple layer Bi2Te3 nanowires: Growth and thermoelectric properties
P. Schönherr, D. Kojda, V. Srot, S. F. Fischer, P. A. Van Aken, and T. Hesjedal
APL Mat. 5, 086110 (2017).
DOI:10.1063/1.4986524
Short abstract
Free-standing millimetre-long Bi2Te3 sub-micron belts catalyzed by TiO2 nanoparticles
P. Schönherr, F. Zhang, D. Kojda, R. Mitdank, M. Albrecht, S. F. Fischer, and T. Hesjedal
Nanoscale Res. Lett. 11: 308 (2016).
DOI:10.1186/s11671-016-1510-x
Short abstract
Surface effects on thermoelectric properties of metallic and semiconducting nanowires
D. Kojda, R. Mitdank, S. Weidemann, A. Mogilatenko, Z. Wang, J. Ruhhammer, M. Kroener, W. Töllner, P. Woias, K. Nielsch, and S. F. Fischer
Phys. Status Solidi A 213, No. 3, 557–570 (2016).
DOI:10.1002/pssa.201532464
Short abstract
Feature Article
Temperature-dependent thermoelectric properties of individual silver nanowires
D. Kojda, R. Mitdank, M. Handwerg, A. Mogilatenko, M. Albrecht, Z. Wang, J. Ruhhammer, M. Kroener, P. Woias, and S. F. Fischer
Phys. Rev. B 91, 024302 (2015).
DOI: 10.1103/PhysRevB.91.024302
Short abstract
Dielectrophoretic investigation of Bi2Te3 nanowires — a microfabricated thermoelectric characterization platform for measuring the thermoelectric and structural properties of single nanowires
Z. Wang, D. Kojda, N. Peranio, M. Kröner, R. Mitdank, K. Nielsch, W. Töllner, S. F. Fischer, S. Gutsch, M. Zacharias, O. Eibl, and P. Woias
Nanotechnology 26, 125707 (2015).
DOI: 10.1088/0957-4484/26/12/125707
Short abstract
The Effect of a Distinct Diameter Variation on the Thermoelectric Properties of Individual Bi0.39Te0.61 Nanowires
D. Kojda, R. Mitdank, A. Mogilatenko, W. Töllner, Z. Wang, M. Kröner, P. Woias, K. Nielsch, and S. F. Fischer
Semicond. Sci. Technol. 29, Special Issue, 124006 (2014).
DOI: 10.1088/0268-1242/29/12/124006
Short abstract
2014 - Highlight Article
Thermoelectric Properties Investigation of Single Nanowires by Utilizing a Thermoelectric Nanowire Characterization Platform
Z. Wang, J. Ruhhammer, S. Adhikari, R. Rostek, D. Moser, O. Paul, D. Kojda, R. Mitdank, S. F. Fischer, W. Toellner, K. Nielsch, M. Kroener, and P. Woias
Proc. IEEE NEMS 2013, 738-741 (2013).
DOI: 10.1109/NEMS.2013.6559834
Electrical conductivity and Seebeck coefficient measurements of single nanowires by utilizing a microfabricated thermoelectric nanowire characterization platform
Z. Wang, S. S. Adhikari, M. Kroener, D. Kojda, R. Mitdank, S. F. Fischer, W. Toellner, K. Nielsch, and P. Woias
IEEE 26th International Conference on Micro Electro Mechanical Systems (MEMS), 508-511, (20.-24. Jan. 2013).
DOI: 10.1109/MEMSYS.2013.6474290
Porous Nanostructures and Thermoelectric Power Measurement of Electro-Less Etched Black Silicon
G.D. Yuan, R. Mitdank, A. Mogilatenko, and S. F. Fischer
J. Phys. Chem. C 116, 13767−13773 (2012).
DOI: 10.1021/jp212427g
Enhanced magneto-thermoelectric power factor of a 70 nm Ni-nanowire
R. Mitdank, M. Handwerg, C. Steinweg, W. Töllner, M. Daub, K. Nielsch, and S. F. Fischer
J. Appl. Phys. 111, 104320 (2012).
DOI: 10.1063/1.4721896
Coherent spin dynamics in Permalloy-GaAs hybrids at room-temperature
P. E. Hohage, J. Nannen, S. Halm and G. Bacher, M. Wahle, S. F. Fischer, U. Kunze D. Reuter, and A. D. Wieck
Appl. Phys. Lett. 92, 241920 (2008).
DOI: 10.1063/1.2943279
Aging phenomena in nanopatterned permalloy wires
T. Last, M. Wahle, S. Hacia, S. F. Fischer, and U. Kunze
Physica B 384, 9-11 (2006).
DOI: 10.1016/j.physb.2006.05.022
Magnetotransport study of nanoscale Permalloy-Si tunnelling structures in lateral spin-valve geometry
S. Hacia, T. Last, S. F. Fischer, and U. Kunze
J. Phys. D: Applied Physics 37 (9), 1310-1315 (2004).
DOI: 10.1088/0022-3727/37/9/002
Optimization of nanostructured permalloy electrodes for a lateral hybrid spin-valve structure
T. Last, S. Hacia, S. F. Fischer, and U. Kunze
J. Appl. Phys. 96, 6706-6711 (2004).
DOI: 10.1063/1.1810197
Study of spin-valve operation in Permalloy-SiO2-Silicon nanostructures
S. Hacia, T. Last, S. F. Fischer, and U. Kunze
J. Supercond.: Incorperating Novel Magnetism 16 (1), 187-190 (2003).
DOI: 10.1023/A:1023242330715
Hexagonally ordered 100 nm period nickel nanowire arrays
K. Nielsch, R.B. Wehrspohn, J. Barthel, J. Kirschner, and U. Gösele, S. F. Fischer, and H. Kronmüller
Appl. Phys. Lett. 79 (9), 1360-1362 (2001).
DOI: 10.1063/1.1399006