2024-03-28T21:35:23Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1355792022-12-15T08:23:15Zcom_10261_36com_10261_4col_10261_415
2016-08-17T07:45:49Z
urn:hdl:10261/135579
Optimization of bismuth telluride films and nano-wire arrays via electrodeposition for thermoelectric applications
Caballero-Calero, Olga
Abad Mayor, Begoña
Díaz Chao, Pablo
Muñoz Rojo, Miguel
Martín Pérez, Jaime
Manzano, Cristina V.
Martín-González, Marisol
Comunicación presentada en el 3rd Early Stage Researchers Workshop in Nanoscience, celebrado en Madrid el 27 y 28 de junio de 2013.
Due to the current world’s demand for energy, there is a great interest in thermoelectricity, which offers the
possibility of increasing the sustainability of our electrical system. Thermoelectric materials can convert heat into
electricity and vice versa, and thus they offer a way of recovering wasted heat produced in engines, industrial processes
and others into usable power. However, one of the main problems for their actual use is their low efficiency in this
conversion. This efficiency is directly related with what is called the thermoelectric figure of merit, described by
ZT=(S2·σ·T)/κ ,where S, σ, κ, and T stand for the Seebeck coefficient, electrical and thermal conductivities, and the
absolute temperature, respectively. Given that in classical physics S, σ, and κ, are correlated, the improvement of the
efficiency is not straightforward. Nevertheless, in 1993 a theoretical work suggested that the efficiency could be greatly
enhanced by reducing the dimensionality of the structures under studied and working in the nano-scale. Therefore, much
experimental effort has been done to achieve these kind of structures and in some cases, an enhancement of the ZT
value has been achieved, although this has not been due to the quantum confinement to the charge carriers, as it was
theoretically predicted, but to an increase of the κ due to the increased number of interface boundaries in nanostructures.
Among the most efficient thermoelectric materials used for applications at room temperature, bismuth telluride
(Bi2Te3) and its different alloys stand out, with a ZT for Bi2Te3of around 1 at RT [2]. We present here an optimized
method of obtaining films and nanowire arrays via electrochemical deposition in a conventional three-electrode cell.
Different ways of improving the quality of the obtained films have been studied (working electrode, constant and
pulsed potentials, different chemical baths, etc.) in order to obtain highly oriented (110) films, which are the most
favorable for out-of-plane applications. Then, nanostructuration has been achieved by changing the working
electrode to porous alumina templates and realizing the electrochemical deposition inside the pores. The samples
produced have been characterized using SEM, EDX, AFM, XRD, and Raman spectrometry, and in the case of the
films, their transport properties have also been measured.
2016-08-17T07:45:49Z
2016-08-17T07:45:49Z
2013-06
2016-08-17T07:45:49Z
comunicación de congreso
3rd Early Stage Researchers Workshop in Nanoscience (2013)
http://hdl.handle.net/10261/135579
eng
Sí
openAccess