Rapid growth of nanocrystalline CuInS2 thin films in alkaline medium at room temperature

Layer-by-layer (LbL) deposition of CuInS2 (CIS) thin films at room temperature (25 8C) from alkaline CuSO4 + In2(SO4)3 and Na2S precursor solutions was reported. The method allowed self-limited growth of CIS films with nanocrystalline structure and composed of densely packed nanometer-sized grains. The as-deposited CIS film was 250 nm thick and composed of closely packed particles of 20–30 nm in diameter. The alkaline cationic precursor solution was obtained by dissolving CuSO4 and InSO4 in deionized water with a appropriate amount of hydrazine monohydrate (H–H) and 2,20,200-nitrilotriethanol (TEA). CIS films were annealed at 200 8C for 2 h and effect of annealing on structural, optical, and surface morphological properties was thoroughly investigated by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV– vis spectrometer, C-V, and water contact angle techniques, respectively.