Annealing Effect on Seebeck Coefficient of SiGe Thin Films Deposited on Quartz Substrate

Kaneez Fatima,Muhammad Asghar,Adnan Ali,Hadia Noor,Eduard Monakhov

doi:10.3390/coatings11121435

Abstract

Over the past few years, thermoelectrics have gained interest with regard to thermoelectricity interconversion. The improvement in the efficiency of the thermoelectric material at an ambient temperature is the main problem of research. In this work, silicon–germanium (SiGe) thin films, owing to superior properties such as nontoxicity, high stability, and their integrability with silicon technologies, were studied for thermoelectric applications. P-type SiGe thin films were deposited on quartz substrates by DC/RF magnetron sputtering and annealed at three different temperatures for 1 hour. Significant enhancement in the Seebeck coefficient was achieved for the sample annealed at 670 °C. A high power factor of 4.1 μWcm−1K−2 was obtained at room temperature.

Highlights

Over the last few years, thermoelectric materials have been compelling ample consideration among the scientific community for use in generating electricity from heat, establishing a sustainable and clean energy source [1]
The scanning electron microscopy (SEM) images of the as-deposited and annealed p-type SiGe thin films are presented in Figure 6; the average grain size in each image was estimated with the help of ImageJ software
The results show that the optimal annealing temperature for the p-type SiGe alloy thin films was around 670 °C

Summary

Experimental Details

The p-type SiGe films were deposited on a pre-cleaned quartz substrates using singlecrystal heavily doped p-type Si (99.9999% pure and ρ = 0.005–0.020 Ω.cm), and singlecrystal n-type Ge (99.999% pure and ρ > 0.1 Ω.cm) targets by DC/RF Magnetron SputterNanoPVD (Model: S10A, Moorfield, UK). The deposition was carried out at room temperature with a rotating substrate (rotation speed of 2 rpm). Pre-sputtering was carried out to clean the surface of the targets with closed shutters to avoid any contamination of the deposited film. 1. Schematic diagram of co-sputtering physical vapor deposition (nano-PVD). 1. Schematic diagram of co-sputtering by physicalby vapor deposition (nano-PVD)

Parameters for deposition of SiGe thin

Results and Discussion

The from

Influence

Thermoelectric

Conclusions