Mo/CIGS/CdS Structures by E‐ALD

The chalcopyrite CuIn(1‐x)GaxSe2 (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.