Investigation of optical and electrical properties of Cobalt-doped Ge-Sb-S thin film

• Published in: Results in physics 2019-06, Vol.13, p.102218, Article 102218
• Main Authors: Musa, Ishaq, Qamhieh, Zaid, Mahmoud, Saleh, El-Shaer, Mohamad, Ayesh, Ahmad, Qamhieh, Naser
• Format: Article
• Language: English
• Subjects: Amorphous chalcogenides; Capacitance measurements; Cobalt doping; Optical band gap; Raman spectroscopy
• ISSN: 2211-3797; 2211-3797
• DOI: 10.1016/j.rinp.2019.102218

•Amorphous Germanium Antimony Sulphide (Ge30 Sb10 S60) doped with Co.•Calculation the optical band gap of Ge30 Sb10 S60 doped with Co from UV–Visible Investigation the vibrational modes of Ge30 Sb10 S60 doped with Co.•Measurements the capacitance and conductance versus voltage, and the activation energy. Amorphous Germanium Antimony Sulphide (Ge-Sb-S) doped with Cobalt (Co) have been deposited on glass substrates by thermal evaporation technique on a glass substrate. The films deposited onto glass substrates are characterized by Energy Dispersive X-ray Fluorescence Spectrometer, UV–VIS spectrophotometer, Raman spectroscopy, and Capacitance-Voltage Keithley meter. The optical band gap was calculated from the UV–Visible spectrum and found to be 2.05 eV. Raman spectroscopy measurements reveal that a wide band spectrum from 300 to 410 cm−1 centered at 355 cm−1. The Raman shift peaks at 325 cm−1 and 350 cm−1 are as-signed to the bond stretching mode Sb-S and Ge-S, respectively. In addition, from the obtained Raman spectra it is concluded that the presence of Co doped with Ge-Sb-S. The capacitance and conductance versus voltage measurements were performed at different temperatures. The results show a slight increase in the capacitance with temperature and it reaches a maximum value around 150 °C, and eventually it becomes negative. This behavior is interpreted in terms of the nucleation growth process and the thermally activated conduction process with measured activation energy of 0.79 eV.