Abstract
The field of amorphous carbon (a-C) contains a range of carbon-based materials: glassy carbon, graphite-like carbon, diamond-like carbon, hydrogenated a-C and doped a-C. These types of a-C can be distinguished by bonding configurations of carbon atoms and doping elements. Recently, it was found that a-C had remarkable electric, magnetic and optical properties. Heterostructures composed of a-C and n-type semiconductors could present good rectifying behaviors, showing the potential for various device applications. Non- or magnetically doped a-C also exhibited positive magnetoresistance (PMR), photovoltaic and photoconductive effects. All these physical properties can be attributed to their special disordered structure.
Here, we mainly investigate magnetoresistance, photoconductivity and strain effect of magnetically doped a-C/Si heterostructure. By doping cobalt into a-C films, remarkable physical properties could be emerged in such a system. . Transmission electron microscopy (TEM) was used to investigate the microstructure of our samples. It was observed that self-assembled Co nanoparticles were formed in a-C matrix. The great enhancement of magnetoresistance, photoconductivity and strain effect of a-C films might be attributed to this feature.