Electrochemical quartz crystal microbalance study of the electrodepositionmechanisms of CuInSe2 thin films

Electrodeposition mechanisms of CuInSe2 thin films from SCN- baths were stu died by cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The formation of CuInSe2 was confirmed to proceed via the induced c odeposition mechanism at more positive potentials than where Cu+ or In3+ al one are reduced. The reaction probably proceeds via Cu2-xSe formation becau se no InySe compounds could be deposited at the potential range where CuInS e2 formation was observed. The slope of the Deltaf vs. DeltaQ plot correspo nding to the CuInSe2 formation decreased during the cyclic voltammogram unt il it settled to a constant value which suggests that the compound formatio n begins on the previously formed Se film and that the deposition mechanism changes during the cyclic voltammogram when the Se film becomes covered wi th the compound. A wide potential range was observed where the slope of the Deltaf vs. DeltaQ plot was constant. Film deposition at constant potential s also yielded essentially equal slopes. (C) 2001 The Electrochemical Socie ty. All rights reserved.