Anomalous electrical transport properties of amorphous carbon films on Si substrates

Amorphous carbon (a-C) films are deposited on n-Si substrates at different temperatures using pulsed laser deposition. Some anomalous current-voltage (I-V) characteristics of the a-C/n-Si are reported. The films deposited at 27 °C have an apparent voltage-induced switch effect, and the value of the switch voltage decreases with increasing temperature. However, the I-V characteristics of the a-C/n-Si deposited at 300 °C and 500 °C are completely different from those deposited at 27 °C. The anomalous I-V characteristics should be of interest for various applications such as field effect devices. In addition, the magnetoresistance (MR) and the resistance of the a-C/n-Si have been studied. Finally, we interpret the anomalous I-V characteristics and MR observed by use of energy band theory.