Silicon electrodeposition from the KF–KCl–KI–K2SiF6 melt

Yu. P. Zaikov, S. I. Zhuk, A. V. Isakov, O. V. Grishenkova, V. A. Isaev

ABSTRACT:

The initial stages of silicon electrodeposition on the glassy carbon electrode in molten mixture of fluoride, chloride, iodide, and potassium hexafluosilicate were investigated at 750°C. The silicon nucleation and growth processes were studied using cyclic voltamperometry, chronamperometry, and scanning electron microscopy. At all stages being studied the silicon electrocrystallization process was established to occur according to the mechanism of instantaneous nucleation with diffusion controlled growth, and the potassium iodide addition of 2–4 wt % does not affect significantly on the silicon depositions morphology, obtained under galvanostatic conditions. The increase of the potassium iodide concentration in melt was shown to result in formation of more compact silicon deposits.

KEYWORDS:

 electrodeposition, silicon, melt, nucleation, growth, diffusion