Electrochemical Atomic Layer Deposition of CuInSe2 on Au Surface

CuInSe2 (CIS) thin film growth on Au/glass slide surface was investigated by electrochemical atomic layer deposition (E-ALD) in superlattice sequence in ambient laboratory conditions without any heat treatment processes involved. The electrochemical behavior of Cu, In, and Se on the Au surface was surveyed, the underpotential deposition phenomena of In was demonstrated for the first time and a various set of potentials for the three elements were considered to fabricate thin CIS films by specific superlattice sequencing. The crystal structure, elemental composition, topography, and photoelectrochemical behavior of each film produced were evaluated with the aim of finding a new set of conditions for producing stoichiometric CIS films. A good stoichiometric film of Cu0.99In0.98Se2.00 was successfully prepared by applying 50 periods of the superlattice sequence of 3(InaSeb) + 1(CucSed) with the new deposition potentials of 0.08, -0.55, and -0.05 V for Cu, In, and Se precursor solutions, respectively. The resulting E-ALD film was found to exhibit a p-type semiconductivity.