This work investigates the growth of polycrystalline alpha-HgI2 thick films from physical vapor deposition. By varying the growth conditions, the as-deposited thick films are characterized by scanning electron microscopy, X-ray diffraction, current-voltage and photoconductivity measurements. The growth mechanism and its effects to the properties of these polycrystalline alpha-HgI2 thick films are then discussed. Finally, the best deposition conditions for polycrystalline alpha-HgI2 thick films compactly formed by separated columnar monocrystallines with uniform orientation along c-direction and with good crystallinity are reported. (c) 2005 Elsevier B.V. All rights reserved.