Silver-Doped Diamond-Like Carbon (DLC:Ag) Nanocomposite Films for Solar Tracking Applications

Diamond-like carbon (DLC) films are often investigated for their mechanical properties. In this report, we assessed the electrical and photovoltaic characteristics of DLC:Ag composite films produced for solar tracking and/or photodetector device purposes. We used the magnetron sputtering technique to prepare DLC:Ag thin films where DLC and Ag were co-deposited on Si wafers. Structural characterization of the thin films was performed using AFM, EDX, and Raman spectroscopy. Current–voltage, capacitance–voltage and conductance–voltage characterizations were employed to assess the electrical characteristics and photovoltaic characteristics of the DLC:Ag thin films. I–V characteristics were characterized under various illumination intensities to assess the effect of light intensity on the DLC:Ag composite films. We found that silver-doped DLC composite thin films are responsive to light and exhibit detector-like behaviour. Barrier height was found to be between 0.55 eV and 0.81 eV while the ideality factor was calculated to be between 1.94 and 7.11. It was found that photovoltaic and diode properties were affected by applied illumination intensities. C–V characteristics indicated that the electrical properties of the thin films are responsive to the signal frequency. The density of interface states was calculated which was thought to be a factor related to this behaviour.