Various Ni-doped carbon (C：Ni) thin films were fabricated using different Ni target power densities by unbalanced magnetron sputtering (UBM). The effects of target power density on the structural, physical, surface, and electrical properties of C：Ni films were investigated. The UBM C：Ni thin films exhibited uniformly smooth surfaces. The rms surface roughness and friction coefficient values of the C：Ni films decreased with the increase in target power density. The physical properties of the films such as hardness and elastic moduli increased while their electrical properties such as resistivity decreased with the increase in the target power density. These results show that an increase of the power density leads to an increase in the proportion of Ni and nanocrystallization of the amorphous carbon film; this contributes to the changes observed in the physical and electrical characteristics.

Mo doped carbon (C:Mo) thin films were fabricated with various Mo target power densities by unbalanced magnetron sputtering (UBM). The effects of target power density on the surface, structural, and electrical properties of C:Mo films were investigated. UBM sputtered C:Mo thin films exhibited smooth and uniform surfaces. However, the rms surface roughness of C:Mo films were increased with the increase of target power density. Also, the resistivity value of C:Mo film as electrical properties was decreased with the increase of target power density. From the performance of organic thin filml transistor using conductive C:Mo gate electrode, the carrier mobility, threshold voltage, and on/off ratio of drain current (Ion/Ioff) showed 0.16 cm²/V·s, -6.0 V, and 7.7×10⁴, respectively.

We investigated the characterizations of carbon films fabricated by dual magnetron sputtering under various film thickness for the electrodes in TCO-less DSSC (dye-sensitized solar cells). Carbon films prepared at various conditions were exhibited smooth and uniform surfaces without defects. Also, the rms surface roughness of carbon films was decreased from 2.25 nm to 1.0 nm with the increase of film thickness. The sheet resistance as the electrical properties are improved from 11.2×10^-3 to 2.28×10^-3 with the increase of film thickness. In the results, the performance of TCO-less DSSC critically depended on the film thickness of working electrodes, indicating the conductivity of carbon films.