Thermoelectric properties of nanostructured porous-polysilicon thin films - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Nano Energy Année : 2021

Thermoelectric properties of nanostructured porous-polysilicon thin films

Résumé

In this paper, we address the optimization of the electrical and thermoelectrical properties of nanostructured polysilicon material for integration in thermoelectric (TE) devices. In particular, we describe an original method to build a superficial and nanostructured porous polysilicon (POpSi) thin film on a Silicon substrate. This latter is electrically isolated from the conductive Silicon substrate by an SiO2 interlayer for Van der Pauw electric and home-made thermoelectric measurements. From the characterization data, we demonstrate that the nano-structuration brought by porosification of polysilicon layers (polySi) breaks their thermal conductivity by a factor of about 30 and has no detrimental impact on their Seebeck coefficient: a POpSi with up to 62% porosity has an experimental Seebeck value of 260 μV/K when the standard polysilicon, it is built from, is n type with a carrier density of 3.4E+19/cm3. On the other hand, the benefit of the thermal conductivity reduction clearly over-compensates the degradation of the experimental electrical conductivity measured in the POpSi layers: in terms of the figure of merit ZT, a 25-fold increase in a POpSi layer with 44% porosity is seen compared to the standard polySi layer (it increases from 0.004 to 0.1). Such a novel material is a viable candidate for planar thermoelectric devices using Silicon technologies. In this effort, we discuss the integration of a POpSi thin film with optimum porosity into a planar TE microgenerator (μTEG) with suspended membranes supported by a simulated conversion efficiency increased by 28% compared to a μTEG integrating the standard polySi layer counterpart.
Fichier principal
Vignette du fichier
Ziouche_NANOEN_105553_2021.pdf (1.32 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-02990079 , version 1 (06-07-2021)

Identifiants

Citer

Katir Ziouche, Ibrahim Bel-Hadj, Zahia Bougrioua. Thermoelectric properties of nanostructured porous-polysilicon thin films. Nano Energy, 2021, 80, pp.105553. ⟨10.1016/j.nanoen.2020.105553⟩. ⟨hal-02990079⟩
53 Consultations
105 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More