Investigation of Seebeck Effect in Metal Oxide Nanowires for Powering Autonomous Microsystems
The Seebeck effect in ZnO (n-type) and CuO (p-type) nanowire bundles grown on alumina substrates has been investigated. By combining n- and p-type nanostructured elements, a planar thermoelectric device has been proposed and characterized, confirming the
- PDF / 206,811 Bytes
- 5 Pages / 439.37 x 666.142 pts Page_size
- 95 Downloads / 153 Views
1 Introduction Quasi-monodimensional metal oxide nanostructures have been recently considered as promising candidates to develop high-efficiency and high-temperature thermoelectric devices due to their reduced dimensionality and excellent durability at high temperature [1]. The fabrication of a thermoelectric generator (TEG) requires both n- and p-type elements. To this purpose, bundles of ZnO (n-type) and CuO (p-type) nanowires have been grown by thermal evaporation process [2] and thermal oxidation techniques [3], respectively, and a planar thermoelectric generator has been fabricated.
2 Material Preparation The deposition technique for zinc oxide nanowires consists in the thermally driven evaporation of a powder of bulk metal oxides followed by condensation on a substrate in an alumina tubular furnace capable to reach high temperatures (≈1,500 °C), needed to initiate the decomposition and the evaporation of metal oxide powder [2]. The nanowires have been fabricated on alumina 20 × 20 mm2 substrates with Au nanoparticles deposited by RF sputtering as catalyst.
S. Dalola (*) • V. Ferrari Dipartimento di Ingegneria dell’Informazione, Università degli Studi di Brescia, Via Branze 38, 25123 Brescia, Italy e-mail: [email protected] G. Faglia • E. Comini • M. Ferroni • C. Soldano • D. Zappa • G. Sberveglieri SENSOR Lab, Università degli Studi di Brescia and CNR-IDASC, Via Valotti 9, 25133 Brescia, Italy C. Di Natale et al. (eds.), Sensors and Microsystems: Proceedings of the 17th National Conference, Brescia, Italy, 5-7 February 2013, Lecture Notes in Electrical Engineering 268, DOI 10.1007/978-3-319-00684-0_1, © Springer International Publishing Switzerland 2014
3
4
a
S. Dalola et al.
b
DVma Probing tip
Probing tip
Peltier cell A
Peltier cell B
Nanowires
Temperature Sensor Pt100
TA
DT
TB
Temperature Sensor Pt100
Fig. 1 (a) Picture of the fabricated planar TEG. (b) Schematic diagram of the experimental setup for the measurement of the thermoelectric response of nanowires samples
Copper oxide nanowires have been grown by thermal oxidation of metallic Cu thin film layer, previously deposited by RF magnetron sputtering on 20 × 20 mm2 alumina substrates [3]. By combining n- and p-type nanostructured elements, a planar TEG consisting of five ZnO and CuO thermocouples, electrically connected in series and thermally in parallel, has been designed and fabricated. Thermoelectric material depositions have been patterned via shadow mask technique on alumina 20 × 20 mm2 substrates to form an array of elements. Each element consists of an S-shaped strip 20 mm in length and 1 mm in width. The electrical contact is provided by the overlap of adjacent strips. ZnO nanowires have been grown by thermal evaporation technique before copper deposition, to avoid contaminations; then the entire device has been oxidized in a furnace. A top-view picture of the planar thermoelectric generator is shown in Fig. 1a.
3 Measurement of the Thermoelectric Response The thermoelectric response of the fabricated samples
Data Loading...
