Wagner, Michael Florian Peter (2018)
Bi and Sb Nanowire Assemblies for Thermoelectric Applications.
Technische Universität Darmstadt
Dissertation, Erstveröffentlichung
Kurzbeschreibung (Abstract)
This thesis presents the fabrication and characterization of Bi(1-x)Sb(x) nanowire assemblies with wellcontrolled and systematically adjusted wire diameter, composition, and vertical or tilted geometrical alignment. The nanowire assemblies were fabricated by means of ion-track technology combining chemical etching of ion-irradiated polymer membranes with electrodeposition of Bi and Sb into track-etched nanochannels. By systematic variation of the etching and deposition conditions, including pulsed potential parameters and surfactant concentration in the electrolyte, the fabrication process was optimized yielding homogeneously grown, uniform nanowire assemblies and networks. The influence of the deposition parameters on morphology and crystalline structure of the resulting Bi, Sb and Bi(1-x)Sb(x) nanowires and networks was investigated by means of X-ray diffraction, high resolution transmission and scanning electron microscopy. Seebeck coefficient and electrical resistance of the nanowire assemblies were investigated in detail as a function of nanowire diameter and temperature. The results confirm the p- and n-type behavior of the Sb and Bi nanowires and provide evidence of the influence of size effects on the thermoelectric transport properties. In addition, a method to measure all relevant thermoelectrical cross-plane properties to deduce the thermoelectric efficiency of a given nanowire assembly was developed. This includes the measurement of the electrical and thermal conductivity as well as the Seebeck coefficient of a nanowire assembly. Finally, more complex nanowire systems were fabricated by combining ion-track nanotechnology and microtechnology to prepare thermocouples formed by Sb and Bi nanowire arrays. These three-dimensional nanowire assemblies of parallel or interconnected nanowires with adjustable diameter and density, embedded in polymer templates, are of great interest for future implementation as e.g. flexible infrared sensors.
Typ des Eintrags: | Dissertation | ||||
---|---|---|---|---|---|
Erschienen: | 2018 | ||||
Autor(en): | Wagner, Michael Florian Peter | ||||
Art des Eintrags: | Erstveröffentlichung | ||||
Titel: | Bi and Sb Nanowire Assemblies for Thermoelectric Applications | ||||
Sprache: | Englisch | ||||
Referenten: | Trautmann, Prof. Dr. Christina ; Ensinger, Prof. Dr. Wolfgang | ||||
Publikationsjahr: | 30 Mai 2018 | ||||
Ort: | Darmstadt | ||||
Datum der mündlichen Prüfung: | 24 August 2018 | ||||
URL / URN: | https://tuprints.ulb.tu-darmstadt.de/8063 | ||||
Kurzbeschreibung (Abstract): | This thesis presents the fabrication and characterization of Bi(1-x)Sb(x) nanowire assemblies with wellcontrolled and systematically adjusted wire diameter, composition, and vertical or tilted geometrical alignment. The nanowire assemblies were fabricated by means of ion-track technology combining chemical etching of ion-irradiated polymer membranes with electrodeposition of Bi and Sb into track-etched nanochannels. By systematic variation of the etching and deposition conditions, including pulsed potential parameters and surfactant concentration in the electrolyte, the fabrication process was optimized yielding homogeneously grown, uniform nanowire assemblies and networks. The influence of the deposition parameters on morphology and crystalline structure of the resulting Bi, Sb and Bi(1-x)Sb(x) nanowires and networks was investigated by means of X-ray diffraction, high resolution transmission and scanning electron microscopy. Seebeck coefficient and electrical resistance of the nanowire assemblies were investigated in detail as a function of nanowire diameter and temperature. The results confirm the p- and n-type behavior of the Sb and Bi nanowires and provide evidence of the influence of size effects on the thermoelectric transport properties. In addition, a method to measure all relevant thermoelectrical cross-plane properties to deduce the thermoelectric efficiency of a given nanowire assembly was developed. This includes the measurement of the electrical and thermal conductivity as well as the Seebeck coefficient of a nanowire assembly. Finally, more complex nanowire systems were fabricated by combining ion-track nanotechnology and microtechnology to prepare thermocouples formed by Sb and Bi nanowire arrays. These three-dimensional nanowire assemblies of parallel or interconnected nanowires with adjustable diameter and density, embedded in polymer templates, are of great interest for future implementation as e.g. flexible infrared sensors. |
||||
Alternatives oder übersetztes Abstract: |
|
||||
URN: | urn:nbn:de:tuda-tuprints-80631 | ||||
Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 500 Naturwissenschaften 500 Naturwissenschaften und Mathematik > 530 Physik 500 Naturwissenschaften und Mathematik > 540 Chemie 600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften und Maschinenbau |
||||
Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Ionenstrahlmodifizierte Materialien |
||||
Hinterlegungsdatum: | 14 Okt 2018 19:55 | ||||
Letzte Änderung: | 14 Okt 2018 19:55 | ||||
PPN: | |||||
Referenten: | Trautmann, Prof. Dr. Christina ; Ensinger, Prof. Dr. Wolfgang | ||||
Datum der mündlichen Prüfung / Verteidigung / mdl. Prüfung: | 24 August 2018 | ||||
Export: | |||||
Suche nach Titel in: | TUfind oder in Google |
Frage zum Eintrag |
Optionen (nur für Redakteure)
Redaktionelle Details anzeigen |