Effect of Heat and Light on Electrical Properties of Si-CNT Junction

Abstract

Plasma sputtering was used to deposit carbon layer from pure graphite with thicknesses (20, 54, 63 nm) on a p-type silicon wafer substrate for the preparation of a Si-CNT (Silicon-Carbon Nano Tubes) junction without any catalyst. The I-V characteristics of the junction were found to be similar to that of the diode, which confirm that the carbon layer or, in other words, that the carbon nanotubes are acting as an n-type semiconductor. The effect of heat and light illumination on the I-V characteristics is studied. At temperatures (32, 40, 50 and 60 o C), the I-V characteristics shows increase in conductivity with increasing the temperature for a certain thickness. The effect of light on I-V characteristics has also been studied showing an increase in current flow, the effect of both heat and light illumination is more pronounced at low values of the thickness of the CNT layer due to their low resistivity.