Fe-, Ni- and Co-induced crystallization of ge thin films fabricated on different substrates for photovoltaic applications

2018-07-06
Kabaçelik, İsmail
Kulakcı, Mustafa
Turan, Raşit
Metal-induced (Fe-, Ni- and Co-) crystallization of amorphous germanium (a-Ge) thin films were investigated by depositing Ge on c-Si (100) and glass substrates by means of electron beam evaporation. The samples were exposed to post-annealing temperatures of 300, 400 and 500 o C for 1 hour (h). The crystal structure of the Ge films was characterized with a Raman spectrum and X-ray diffraction (XRD) measurements. The Raman spectrum of the samples as-deposited and annealed at a temperature of 300 °C gives broad Raman band with a peak position at around 277 cm-1. The broad and weak peaks observed near 277 cm-1 can be assigned to the amorphous Ge–Ge TO modes. As the annealing temperature increased from 300 o C to 400 o C, the peak intensity of crystalline Ge–Ge mode increased and amorphous Ge–Ge mode decreased due to improvements in the structural order [1,2]. The XRD diffraction patterns of the as-deposited and annealed at 300 o C Ge films show a very broad peak which indicates amorphous structure of films. The samples annealed at 400 o C exhibit three diffraction peaks at 27o , 46o and 53o , corresponding to the diffraction from (111), (220), and (311) planes of the Ge films for both substrates, respectively. When the annealing temperature is increased to 500 o C, the intensity of the Ge (111) peaks increased significantly. Also, the intensity of the Ge (220) and Ge (311) orientations become gradually stronger with the increase of the annealing temperature. These findings could be very useful to realize inexpensive Ge based electronic and photovoltaic applications.
Citation Formats
İ. Kabaçelik, M. Kulakcı, and R. Turan, “Fe-, Ni- and Co-induced crystallization of ge thin films fabricated on different substrates for photovoltaic applications,” Ankara, Turkey, 2018, p. 178, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/88323.