Silver-induced crystallizations of amorphous germanium (alpha-Ge) thin films were fabricated through electron beam evaporation on crystalline silicon (c-Si) (100), aluminum-doped zinc oxide (AZO), and glass substrates at room temperature. The solid-phase crystallization (SPC) of alpha-Ge films was investigated for various post-annealing temperatures between 300 and 500 degrees C for 60 min. Two crystallization approaches were compared: SPC and metal-induced crystallization (MIC). The structural properties of the Ge thin films fabricated by both methods were studied with Raman and X-ray diffraction (XRD) measurements. The Raman and XRD results indicated that the metal-induced crystallization of the Ge thin films yielded crystallization at temperatures considerably lower than those used in the SPC technique. As expected, the amount of crystallization and the quality of the films were improved with increased annealing temperatures. It was also demonstrated that the same material properties could be obtained using different substrates without any significant variation. (C) 2015 Elsevier B.V. All rights reserved.