PHOTOELECTROCHEMISTRY OF THE INSERTION COMPOUNDS NAXINSE AND LIXINSE

The insertion reaction of Li and Na in lamellar InSe single crystal wa s performed electrochemically in a non-aqueous electrolyte at room tem perature. The insertion product was, at the electrode surface, an inte rcalation compound (LixInSe, NaxInSe) or the result of the chemical de composition of the electrode material (Li2Se, Na2Se). The development of the reaction was followed by photoelectrochemical spectroscopy and by cyclic photocurrent voltammetry performed in situ in the reaction e lectrolyte. A Fermi level shift in the intercalation compound was dedu ced by a flatband shift to lower potential and a small increase of the bandgap energy resulted from the intercalation reaction. The Na-inser ted samples have been analyzed by grazing angle incidence X-ray diffra ction and an increase in the interlayer distance was observed.