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

Abstract

Layer-by-layer (LbL) deposition of CUInS2 (CIS) thin films at room temperature (25 degrees C) from alkaline CUSO4 + In-2(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 2,2',2"-nitrilotriethanol (TEA). CIS films were annealed at 200 degrees C 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. (c) 2005 Published by Elsevier B.V.