Unlocking the thermoelectric potential of nanocrystalline magnesium selenide thin films grown by single stage horizontal tube furnace (SSHTF)

Abstract

In this manuscript, the thin films of Magnesium Selenide (MgSe) were synthesized on a glass substrate using a single-stage horizontal tube furnace (SSHTF) which is supposed to be the simplest and a cost-effective approach. Before the deposition of thin films, the substrate was cleaned using standard methods. A pellet was formed by taking an equal ratio (1:1) of magnesium (Mg) and selenium (Se) powders and then evaporating them at 700oC for 1 h. The flow rate of nitrogen gas (100 SCCM) was maintained during the deposition process to avoid unwanted oxygen. A number of samples were synthesized by varying the source to substrate distance, and some representative samples are chosen for this study. The post-growth samples were characterized using XRD, SEM, and Raman Spectroscopy. The thermoelectric potential of all samples was tested by a home-developed Seebeck system. We have observed some promising values of the Seebeck coefficient (7.175 × 10−5 V/°C) and power factor (6.35 × 10−8 Wm−1oC−2) at optimized source-to substrate distance. These encouraging results will open the door for MgSe-based thermoelectric research and further explore its power generation potential in the future.

keywords: MgSe thin films, Source to substrate distance, Thermoelectric power generation, Vacuum tube furnace