Electrical properties of Mg₂Si thin films on flexible polyimide substrates fabricated by radio-frequency magnetron sputtering

Abstract

Mg₂Si thin films were successfully fabricated on 125-µm-thick flexible polyimide substrates by radio-frequency (RF) magnetron sputtering deposition using a sintered polycrystalline Mg₂Si target. The crystalline orientation of the films was influenced by the substrate temperature (Ts). The produced films exhibit n-type carriers. The electron concentration and mobility of nondoped Mg₂Si films at Ts = RT were 1.9 × 10¹⁶ cm⁻³ and 1.2 cm²/(V s), respectively. The Seebeck coefficient was −748 µV/K at 336 K, and its absolute value decreased with increasing temperature. The power factor was 3.3 × 10⁻⁷ W/(cm K²) at 710 K, which is approximately one order of magnitude lower than that of the bulk sintered Mg₂Si sample.