Electrodeposition of copper indium diselenide (CuInSe2), which is an absorption layer for thin film solar cells, has been studied in the solution containing 11 mmol L-1 CuCl2, 25 mmol L-1 InCl3, 24 mmol L-1 H2SeO3, and 0-500 mmol L-1 KCl. The concentration of KCl was found to strongly influence the morphology, ratio of copper selenides to chalcopyrite, and composition of the CuInSe2 electrodeposit. Increasing the concentration of KCl solution enhanced the Cu and Se content of the CuInSe2 deposit, meanwhile the formation of granular copper selenide secondary phases was promoted. The effect of the concentration of KCl solution on the content of copper selenides was analyzed using energy dispersive spectroscopy, the corresponding reduction current of cyclic voltammetry, and the anodic stripping method. The distinguishable anodic potential between copper selenides and CuInSe2 provided a selective electrochemical etching method to remove the secondary phases from the CuInSe2 electrodeposits. Moreover, the stability of plating solutions as a function of KCl concentrations was tested. The presence of KCl effectively suppressed the suspension formation, signifying enhanced solution stability. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.076302jes] All rights reserved.