One-dimensional electron system and nanoscale thermoelectrics
Density of states (DOS) calculated for InAs nanowires with 10 nm and 20 nm diameter indicate 1D quantum confinement.
Continued scaling, the introduction of non-planar CMOS transistors (FinFET, Gate-all-around FET, nanowire FET) and the changeover to high-mobility channel materials will ultimately lead to noticeable quantum size effects in device characteristics.
We are investigating the transition from 3-dimensional (3D) to 1-dimensional (1D) electronic transport in III–V semiconductor nanowires. Moreover, we aim to improve thermoelectric devices by exploiting the unique electronic and thermal properties of semiconducting nanowires.
We are focusing on advancing the fundamental understanding of thermoelectric on the nanoscale, developing test structures for the precise measurement of relevant parameters and fabricating nanowire-based device structures with enhanced performance.
S. Karg, V. Schaller, A. Gaul, K. Moselund, H. Schmid, B. Gotsmann, J. Gooth, H. Riel
Solid-State Device Research Conference “ESSDERC” (2016).
Experimental investigation of enhanced thermoelectric powerfactor in 1D InAs nanowires.
F. Menges, P. Mensch, H. Schmid, H. Riel, A. Stemmer, B. Gotsmann
Nature Communications 7 (2016).
Imaging temperature fields at the nanoscale is a central challenge in various areas of science and technology. Nanoscopic hotspots, such as those observed in integrated circuits or plasmonic nanostructures, can be used to modify the local properties of matter, govern physical processes, activate chemical reactions and trigger biological mechanisms in living organisms.
P. Mensch, S. Karg, B. Gotsmann, P. Das Kanungo, V. Schmidt, V. Troncale, H. Schmid, H. Riel Solid-State Device Research Conference “ESSDERC” (2013).
Measurements of electrical conductivity and Seebeck coefficient are reported varying the carrier concentration through application of a gate voltage. The temperature dependence of the electron mobility is examined.
Using the Seebeck coefficient to determine charge carrier concentration, mobility, and relaxation time in InAs nanowires
V. Schmidt, P. Mensch, S. Karg, B. Gotsmann, P. Das Kanungo, H. Schmid, H. Riel
Applied Physics Letters 104, 012113 (2014).
Analysis and modelling of the thermoelectric properties of InAs nanowires infer charge carrier concentration, charge carrier mobility, and relaxation time..
S. F. Karg, V. Troncale, U. Drechsler, P. Mensch, P. Das Kanungo, H. Schmid, V. Schmidt, L. Gignac, H. Riel, B. Gotsmann
Nanotechnology 25(30), 305702 (2014).
Precise measurements of a complete set of thermoelectric parameters in a single indium-arsenide nanowire have been performed using highly sensitive, micro-fabricated sensing devices based on the heater/sensor principle.
S. Karg, P. Mensch, B. Gotsmann, H. Schmid, P. Das Kanungo, H. Ghoneim, V. Schmidt, M. T. Björk, V. Troncale, H. Riel
J. Electron. Mater. 42(7) 2409-2414 (2013).
We evaluated a self-heating method to determine the thermal conductivity of individual silicon and indium arsenide (InAs) nanowires. Further, electrical conductivity and Seebeck coefficient (thermopower) were measured.