The chalcopyrite CuIn (1-x) Ga x Se 2 (CIGS) thin films were grown on Mo substrate by electrochemical atomic layer deposition (E-ALD) of superlattice sequencing 2InSe/2GaSe/1CuSe, recently developed on model Au surface by Stickney and coworkers (J. Electrochem. Soc. 161, D141 (2014)). The cyclic voltammetry studies were conducted on copper, selenium, indium and gallium on molybdenum substrate and CIGS films were grown by different numbers of superlattice sequencing. The deposited films were examined for phase and microstructure formations by X-ray diffraction (XRD), scanning electron microscopy (SEM), scanning tunneling microscopy (STM) and energy dispersive spectroscopy (EDS). The XRD pattern corresponded to those of chalcopyrite crystalline phase of CIGS and the crystallite size increased with the number of cycles or periods of whole superlattice sequencing increased. The SEM and STM results were in line with those of XRD by showing that the particle size increased as the number of E-ALD cycles increased. The EDS results revealed the CIGS with near stoichiometry. Finally, the deposited E-ALD films were shown to be photoelectrochemically active with p-type conductivity. We wish to describe the preparation of CuIn (1-x) Ga x Se 2 (CIGS) by means of electrochemical atomic layer deposition (E-ALD) on Mo substrate of each component element in aqueous solutions at ambient laboratory conditions and to show that the resulting films are photoelectrochemically active with p-type conductivity.Solar energy, the prominent energy source of the universe could be properly utilized for the current increasing trends for energy needs of our entire planet. Alternate energy production technologies like thin film solar cells have been successfully competing traditional energy production methods raised over recent years.1-3 The chalcopyrite Cu(In,Ga)(Se/S) 2 modules of thin films are the promising tool in commercially manufacturing thin film photovoltaic (PV) technologies available in PV market today. 4 The chalcopyrites CIGS are compound semiconductors which are largely known for high absorption coefficient (1 × 10 5 cm −1 ) at photons above the bandgap. 5 The Ga substitution can make the compound with highly adjustable bandgap (1.04 eV for CuInSe 2 (x = 0) to 1.68 eV for CuGaSe 2 (x = 1)) 6 with high stability under high energy irradiation. 7,8 The bandgap of the material is more closely found with the optimum conversion efficiency range (1.4 ∼ 1.5 eV) of solar radiation.9 Because of these properties, it attracted considerable interests by the researchers and industrialists to use CIGS as light-absorbing materials for thin film photovoltaic cells.7-10 Recent works on CIGS have achieved the power conversion efficiency up to 22.6% in laboratory scale. [20][21][22][23] These synthesis methods need larger investment in machinery and workspace which involve highly complicated instruments. The difficulties are with the problems in maintaining the laboratory conditions, complicated procedures and unusual release of heat and toxic byprod...

The chalcopyrite CuIn (1-x) Ga x Se 2 (CIGS) thin films and their cadmium sulfide (CdS) window layer structures (CIGS/CdS) were grown on Mo foil substrate in layer-by-layer fashion by electrochemical atomic layer deposition (E-ALD) and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and photoelectrochemical (PEC) activity. XRD shows distinct pattern changes from chalcopyrite to chalcopyrite plus CdS structures upon adding E-ALD CdS layer to CIGS layers on Mo substrate. SEM shows that uniform and homogeneously distributed nanoparticles of CdS formed on top of CIGS layers, and EDS shows the successful preparation of CIGS/CdS structures with good atomic ratios in each layer. PEC performance reveals that bare CIGS films were of p-type conductivity but that CIGS/CdS structures n-type with p-type response near null.

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(In aSe b) + 1(Cu cSe d) 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.