Amorphous and nanocrystalline Mg2Si thin-film electrodes

Abstract

Mg 2 Si films, prepared by pulsed laser deposition (PLD), were amorphous, as prepared, and nanocrystalline following annealing. Their micro-structure and electrochemical characteristics were studied by high resolution transmission electron microscopy (HRTEM) and electrochemical cycling against lithium. HRTEM analysis revealed that some excess Si was present in the films. The more amorphous thinner film exhibited excellent cyclability. However, when the film becomes crystalline, the irreversible capacity loss was more significant during the initial cycling and after ∼50 cycles.Interpretations of the superior stability of the amorphous films are examined.

Oxidation resistance of magnesium silicide under high-temperature air exposure

“…It can also work as a negative electrode component in lithium-ion batteries due to its high capacity and low potential versus lithium even at ambient temperatures [10,11], in thermoelectric [12,13] and in photovoltaic [14] devices. Also it is suitable for structure applications due to low density (1.99 g cm -3 ), high melting point (1085°C) and high Young's modulus (120 GPa.)…”

Polycrystalline Mg2Si thin films: A theoretical investigation of their electronic transport properties

“…Although an abundant literature exists on the fabrication of Mg 2 Si thin films [6][7][8][9][10][11][12][13][14], their thermoelectric properties have not been experimentally investigated. Only a few theoretical studies have been reported on the calculations of Mg 2 Si thin films, either dealing with the structural and electronic characteristics [15], or the thermoelectric properties of the films [16].…”

Optoelectronic properties of Mg2Si semiconducting layers with high absorption coefficients

“…5 So far, various Mg 2 Si layers have been fabricated using (i) sputtering methods, 9,15,16 (ii) solid phase crystallization of Mg/Si stacked layer, 17,18 (iii) co-evaporation of Mg and Si in molecular beam epitaxy (MBE), 5 (iv) pulsed laser deposition, 19 and (v) implantation of Mg ions into Si substrates, followed by rapid thermal annealing. 20 Among these techniques, conventional rf magnetron sputtering is the most suitable technique for the preparation of large-area solar cell modules.…”